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Oregon State University
1.
Morse, Daniel R.
Experiments on a low aspect ratio wing at low Reynolds numbers.
Degree: PhD, Mechanical Engineering, 2008, Oregon State University
URL: http://hdl.handle.net/1957/10009 
► At the start of the 21st century much of the focus of aircraft design has been turned to unmanned aerial vehicles (UAVs) which generally operate…
(more)
▼ At the start of the 21st century much of the focus of aircraft design has been turned to unmanned aerial vehicles (UAVs) which generally operate at much lower speeds in higher risk areas than manned aircraft. One subset of UAVs are Micro Air Vehicles (MAVs) which usually are no larger than 20cm and rely on non-traditional shapes to generate lift at very low velocities. This purpose of this work is to describe, in detail with experimental methods, the flow field around a low aspect ratio wing operating at low Reynolds numbers and at high angles of attack. Quantitative measurements are obtained by Three Component Time Resolved Particle Image Velocimetry (3C TR PIV) which describe the mean and turbulent flow field. This research focuses on the leading edge separation zone and the vortex shedding process which occurs at the leading edge. Streamwise wing tip vortices which dominate the lift characteristics are described with flow visualization and 3C TR PIV measurements. Turbulent Kinetic Energy (TKE) is described at the leading edge over several angles of attack. Turbulent Reynolds stresses in all three directions are described over the wing span and several Reynolds numbers. Two primary cyclic processes are observed within the flow field; one low frequency oscillation in the separated region and one high frequency event associated with leading edge vortex formation and convection. Two length scales are proposed and are shown to match well with each other, one based on leading edge vortex shedding frequency and convective velocity and the other based on mean vortex separation distance. A new method of rendering velocity frequency content over large data sets is proposed and used to illustrate the different frequencies observed at the leading edge.
Advisors/Committee Members: Narayanan, Vinod (committee member).
Subjects/Keywords: Time Resolved; Airplanes – Wings – Fluid dynamics
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APA (6th Edition):
Morse, D. R. (2008). Experiments on a low aspect ratio wing at low Reynolds numbers. (Doctoral Dissertation). Oregon State University. Retrieved from http://hdl.handle.net/1957/10009
Chicago Manual of Style (16th Edition):
Morse, Daniel R. “Experiments on a low aspect ratio wing at low Reynolds numbers.” 2008. Doctoral Dissertation, Oregon State University. Accessed April 15, 2021.
http://hdl.handle.net/1957/10009.
MLA Handbook (7th Edition):
Morse, Daniel R. “Experiments on a low aspect ratio wing at low Reynolds numbers.” 2008. Web. 15 Apr 2021.
Vancouver:
Morse DR. Experiments on a low aspect ratio wing at low Reynolds numbers. [Internet] [Doctoral dissertation]. Oregon State University; 2008. [cited 2021 Apr 15].
Available from: http://hdl.handle.net/1957/10009.
Council of Science Editors:
Morse DR. Experiments on a low aspect ratio wing at low Reynolds numbers. [Doctoral Dissertation]. Oregon State University; 2008. Available from: http://hdl.handle.net/1957/10009
Oregon State University
2.
Krebs, Daniel P.
A technique for spatially resolved wall temperature measurements in microchannel heat sinks using infrared thermography.
Degree: MS, Mechanical Engineering, 2008, Oregon State University
URL: http://hdl.handle.net/1957/8753
► A non-intrusive measurement technique for direct quantitative thermal visualization of channel wall temperatures in two phase microchannel flows using infrared thermography (IRT) is presented. Specifically,…
(more)
▼ A non-intrusive measurement technique for direct quantitative thermal visualization of channel wall temperatures in two phase microchannel flows using infrared thermography (IRT) is presented. Specifically, the measurement of top channel wall temperatures in a fractal-like branching microchannel silicon heat sink during flow boiling is demonstrated and thoroughly documented. Obtaining quantitative local temperature measurements involving IRT poses significant challenges and requires careful consideration with regard to heat sink design, fabrication and calibration as well as data acquisition, reduction and analysis procedures – all of which are addressed and discussed in detail. Also discussed and rigorously quantified are the potentially significant measurement uncertainties associated with obtaining non-intrusive, local data of this nature. Results indicate that temperature maps of the microchannel top wall during flow boiling can be obtained with a spatial resolution of 10 μm and an uncertainty varying from 0.82°C-1.67°C at 25 °C and 0.96°C-2.80°C.
Advisors/Committee Members: Narayanan, Vinod (advisor), Narayanan, Vinod (committee member).
Subjects/Keywords: Infrared; Heat sinks (Electronics)
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APA (6th Edition):
Krebs, D. P. (2008). A technique for spatially resolved wall temperature measurements in microchannel heat sinks using infrared thermography. (Masters Thesis). Oregon State University. Retrieved from http://hdl.handle.net/1957/8753
Chicago Manual of Style (16th Edition):
Krebs, Daniel P. “A technique for spatially resolved wall temperature measurements in microchannel heat sinks using infrared thermography.” 2008. Masters Thesis, Oregon State University. Accessed April 15, 2021.
http://hdl.handle.net/1957/8753.
MLA Handbook (7th Edition):
Krebs, Daniel P. “A technique for spatially resolved wall temperature measurements in microchannel heat sinks using infrared thermography.” 2008. Web. 15 Apr 2021.
Vancouver:
Krebs DP. A technique for spatially resolved wall temperature measurements in microchannel heat sinks using infrared thermography. [Internet] [Masters thesis]. Oregon State University; 2008. [cited 2021 Apr 15].
Available from: http://hdl.handle.net/1957/8753.
Council of Science Editors:
Krebs DP. A technique for spatially resolved wall temperature measurements in microchannel heat sinks using infrared thermography. [Masters Thesis]. Oregon State University; 2008. Available from: http://hdl.handle.net/1957/8753
Oregon State University
3.
Kapsenberg, Florian.
Lateral fluid motion in nucleate boiling through asymmetric surface structures.
Degree: MS, Mechanical Engineering, 2011, Oregon State University
URL: http://hdl.handle.net/1957/21760
► This thesis presents a feasibility study of a means to passively effect liquid motion parallel to a heated surface though surface geometrical modifications. Such a…
(more)
▼ This thesis presents a feasibility study of a means to passively effect liquid motion parallel to a heated surface though surface geometrical modifications. Such a passive system is beneficial for electronics cooling applications as it reduces the pumping equipment normally required in flow loops and is desired for space applications, where launch costs greatly restrict the weight of onboard systems. The surface geometry considered was a repeated array of asymmetric silicon ratchets with reentrant cavities located on the shallow face. A serpentine thin film heater provided heat to the surface. A complete experimental facility in which to perform experiments was designed and constructed as part of this work to comply with requirements set by microgravity flight services in anticipation of future experiments in microgravity.
Experiments were performed using deionized and degassed water at atmospheric pressure at subcoolings of 5°C and 20°C. Applied area averaged heat flux was varied between 2 W/cm² and 19 W/cm² at these conditions. Magnified high-speed videos were used to resolve bubble behavior near the surface. A preferential bubble growth and departure direction was confirmed for both subcoolings and lateral fluid motion was confirmed in the high subcooling condition. Repeatability was confirmed with separate experiment performed 58 days later. Tracking of bubbles was accomplished using a custom bubble-tracking algorithm, designed to resolve only bubbles within a two-dimensional plane normal to the viewing direction.
Instantaneous velocities of individual bubbles parallel to the surface were shown to be in excess of 600 mm/s immediately following departure, and liquid flows with mean velocities between 25 mm/s and 35 mm/s parallel to surface were observed in the plume farther from the surface. A simplified semi-empirical model of bubble growth phase is proposed to explain the observed mean liquid velocities.
Advisors/Committee Members: Narayanan, Vinod (advisor), Liburdy, James A. (committee member).
Subjects/Keywords: Nucleate boiling
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APA (6th Edition):
Kapsenberg, F. (2011). Lateral fluid motion in nucleate boiling through asymmetric surface structures. (Masters Thesis). Oregon State University. Retrieved from http://hdl.handle.net/1957/21760
Chicago Manual of Style (16th Edition):
Kapsenberg, Florian. “Lateral fluid motion in nucleate boiling through asymmetric surface structures.” 2011. Masters Thesis, Oregon State University. Accessed April 15, 2021.
http://hdl.handle.net/1957/21760.
MLA Handbook (7th Edition):
Kapsenberg, Florian. “Lateral fluid motion in nucleate boiling through asymmetric surface structures.” 2011. Web. 15 Apr 2021.
Vancouver:
Kapsenberg F. Lateral fluid motion in nucleate boiling through asymmetric surface structures. [Internet] [Masters thesis]. Oregon State University; 2011. [cited 2021 Apr 15].
Available from: http://hdl.handle.net/1957/21760.
Council of Science Editors:
Kapsenberg F. Lateral fluid motion in nucleate boiling through asymmetric surface structures. [Masters Thesis]. Oregon State University; 2011. Available from: http://hdl.handle.net/1957/21760
Oregon State University
4.
Cardenas, Ruander.
Study of a constrained-film bubble absorber under cycle operating conditions.
Degree: MS, Mechanical Engineering, 2009, Oregon State University
URL: http://hdl.handle.net/1957/11942
► An experimental and numerical study of absorption of ammonia vapor bubbles into a constrained thin film of ammonia-water solution is presented in the context of…
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▼ An experimental and numerical study of absorption of ammonia vapor bubbles into a constrained thin film of ammonia-water solution is presented in the context of a potential reduction in size of a heat-actuated heat pump component. A large-aspect-ratio channel with a depth of 600 µm restricts the thickness of the weak solution film, while ammonia vapor bubbles are injected from a porous wall. Experiments are performed at a nominal system pressure of 6.2 bar absolute and at an inlet weak solution temperature of 75ºC. A counter-flowing coolant in a minichannel removes the generated heat of absorption. The mass flow rate of the weak solution, vapor flow rate, coolant inlet temperature, and mass flow rate of the coolant solution are varied. Two absorber channel geometries are considered: 1) a smooth 600 µm channel, and 2) a stepped geometry that has 2-mm deep trenches across the width of one of the channel walls. The 1-D, steady
state species and energy transport equations, are solved for the smooth-channel absorber to yield, along the length of the channel, concentration and temperature profiles of the solution stream and the temperature profile of the coolant fluid stream.
Experimental results indicate that overall heat transfer coefficients vary from 700 W/m²-K to 2,300 W/m²-K, while the mass transfer conductances range from 0.024 kg/s-m² to 0.24 kg/s-m². The coolant inlet temperature has a significant effect on the mass transfer rates. At the highest inlet coolant temperature of 58ºC, up to 1.5 g/min of vapor is at best absorbed into 35 g/min of weak solution for the smooth absorber plate, while at the lowest coolant temperature of 30ºC, up tp 3 g/min of vapor is absorbed in 35 g/min of weak solution with the same absorber plate. For the stepped absorber geometry, only 1 g/min of vapor is absorbed into 35 g/min of weak solution for the highest coolant temperature of 58ºC, while for the lowest coolant temperature of 30ºC, 5 g/min of vapor is absorbed in 40 g/min of weak solution. Trends of local variation of temperature and convected vapor from the numerical parametric study complement experimental results and provide further insight into the performance of the absorber. Based on the experimental results, a preliminary size estimate for the absorber to operate in a cooling cycle with a 6 kW evaporator load is provided. Other considerations such as strong solution exit subcooling and porous plate pressure drop are also addressed.
Advisors/Committee Members: Narayanan, Vinod (advisor), Apte, Sourabh V. (committee member).
Subjects/Keywords: Ammonia-water absorption; Heat pumps
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APA (6th Edition):
Cardenas, R. (2009). Study of a constrained-film bubble absorber under cycle operating conditions. (Masters Thesis). Oregon State University. Retrieved from http://hdl.handle.net/1957/11942
Chicago Manual of Style (16th Edition):
Cardenas, Ruander. “Study of a constrained-film bubble absorber under cycle operating conditions.” 2009. Masters Thesis, Oregon State University. Accessed April 15, 2021.
http://hdl.handle.net/1957/11942.
MLA Handbook (7th Edition):
Cardenas, Ruander. “Study of a constrained-film bubble absorber under cycle operating conditions.” 2009. Web. 15 Apr 2021.
Vancouver:
Cardenas R. Study of a constrained-film bubble absorber under cycle operating conditions. [Internet] [Masters thesis]. Oregon State University; 2009. [cited 2021 Apr 15].
Available from: http://hdl.handle.net/1957/11942.
Council of Science Editors:
Cardenas R. Study of a constrained-film bubble absorber under cycle operating conditions. [Masters Thesis]. Oregon State University; 2009. Available from: http://hdl.handle.net/1957/11942
Oregon State University
5.
Chewning, Scott R.
Micro adiabatic combustion engine : concept development, simulation and combustion experiments.
Degree: MS, Mechanical Engineering, 2008, Oregon State University
URL: http://hdl.handle.net/1957/9125
► The current proliferation of portable electronic devices for personal communication, business and entertainment has created a demand for high energy density power supplies. A hydrocarbon…
(more)
▼ The current proliferation of portable electronic devices for personal
communication, business and entertainment has created a demand for high energy density
power supplies. A hydrocarbon fuel with a conversion efficiency of over
15% can provide greater energy density than current battery technology for these
applications. Current micro-scale heat engines do not operate at an efficiency great
enough to displace the current electrochemical battery. The MACE concept was
developed to address the key issues limiting the current micro-scale heat engines: heat
losses to the surroundings, leakage, friction and combustion. This thesis covers the
development of a concept micro-scale engine which consists of two pistons,
connected by a regenerator. The pistons are driven by a specific motion linkage to
produce the desired flow patterns and to isolate heat to one region in the engine to
reduce losses. The engine utilizes catalytic combustion which was characterized
using a test apparatus to determine the effects of the equivalence ratio, volumetric
flow rates and volume amounts on the combustion temperature of propane-air on a
platinum catalyst under various flow conditions.
Advisors/Committee Members: Peterson, Richard B (advisor), Narayanan, Vinod (committee member).
Subjects/Keywords: Micro Engine; Adiabatic engines – Design and construction
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APA (6th Edition):
Chewning, S. R. (2008). Micro adiabatic combustion engine : concept development, simulation and combustion experiments. (Masters Thesis). Oregon State University. Retrieved from http://hdl.handle.net/1957/9125
Chicago Manual of Style (16th Edition):
Chewning, Scott R. “Micro adiabatic combustion engine : concept development, simulation and combustion experiments.” 2008. Masters Thesis, Oregon State University. Accessed April 15, 2021.
http://hdl.handle.net/1957/9125.
MLA Handbook (7th Edition):
Chewning, Scott R. “Micro adiabatic combustion engine : concept development, simulation and combustion experiments.” 2008. Web. 15 Apr 2021.
Vancouver:
Chewning SR. Micro adiabatic combustion engine : concept development, simulation and combustion experiments. [Internet] [Masters thesis]. Oregon State University; 2008. [cited 2021 Apr 15].
Available from: http://hdl.handle.net/1957/9125.
Council of Science Editors:
Chewning SR. Micro adiabatic combustion engine : concept development, simulation and combustion experiments. [Masters Thesis]. Oregon State University; 2008. Available from: http://hdl.handle.net/1957/9125
Oregon State University
6.
Kwak, Younghoon.
Experimental study of two-phase gas-liquid flow in a microscale fractal-like branching flow network.
Degree: PhD, Mechanical Engineering, 2008, Oregon State University
URL: http://hdl.handle.net/1957/9049
► Two-phase gas-liquid flows in microscale fractal-like branching channel flow networks were experimentally studied to assess the validity of existing void fraction correlations and flow regimes…
(more)
▼ Two-phase gas-liquid flows in microscale fractal-like branching channel flow networks were experimentally studied to assess the validity of existing void fraction correlations and flow regimes based on superficial gas and liquid velocities. Void fractions were assessed using two different methods. First, void fraction data were acquired using a High-Speed-High-Resolution (HSHR) camera and computed by area-based two-dimensional image analysis. Void fraction data were also computed using a slip ratio, defined as gas velocity over liquid velocity. Liquid velocity represents the bulk-averaged liquid velocity as determined by microscale particle image velocimetry (micro-PIV). Gas velocity was determined by averaging gas-liquid interface velocities made at the channel centerline.
The fractal-like branching channel flow network has five bifurcation levels of different channel widths varying from 400 µm to 100 µm with a fixed channel depth of 250 µm. Each downstream width decreases by 30% whereas the downstream lengths increase by 40%. The total flow length through a single path is approximately 18 mm. Filtered air and deionized water were used as the gas and liquid working fluids, respectively. Mass flow rates of air and water into each k=0 branch were varied from 0.3 g/min to 2.5 g/min and from 5.2x10⁻⁵ g/min to 1.3x10⁻² g/min, respectively. These flow rates yielded superficial air and water velocities through the same branch level between 0.007 m/s and 1.8 m/s and between 0.05 m/s and 0.42 m/s, respectively.
For each branching level, due to an increase in flow area, the superficial liquid and gas flow rates change. A two-phase flow regime map was generated for each level of the fractal-like branching flow network and compared to maps developed using the Taitel and Dukler (1976) model and to maps presented in Chung and Kawaji (2004). Flow regime transitions are well predicted with the Taitel and Dukler (1976) model for each branching level.
Void fraction assessed using the slip ratio shows very good agreement with the homogeneous void fraction model for all branching levels. On the other hand, void fraction determined by area-based two-dimensional image analysis shows better agreement with the void fraction correlation of Zivi (1964).
Advisors/Committee Members: Pence, Deborah V. (advisor), Narayanan, Vinod (committee member).
Subjects/Keywords: microchannel; Two-phase flow
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APA (6th Edition):
Kwak, Y. (2008). Experimental study of two-phase gas-liquid flow in a microscale fractal-like branching flow network. (Doctoral Dissertation). Oregon State University. Retrieved from http://hdl.handle.net/1957/9049
Chicago Manual of Style (16th Edition):
Kwak, Younghoon. “Experimental study of two-phase gas-liquid flow in a microscale fractal-like branching flow network.” 2008. Doctoral Dissertation, Oregon State University. Accessed April 15, 2021.
http://hdl.handle.net/1957/9049.
MLA Handbook (7th Edition):
Kwak, Younghoon. “Experimental study of two-phase gas-liquid flow in a microscale fractal-like branching flow network.” 2008. Web. 15 Apr 2021.
Vancouver:
Kwak Y. Experimental study of two-phase gas-liquid flow in a microscale fractal-like branching flow network. [Internet] [Doctoral dissertation]. Oregon State University; 2008. [cited 2021 Apr 15].
Available from: http://hdl.handle.net/1957/9049.
Council of Science Editors:
Kwak Y. Experimental study of two-phase gas-liquid flow in a microscale fractal-like branching flow network. [Doctoral Dissertation]. Oregon State University; 2008. Available from: http://hdl.handle.net/1957/9049
Oregon State University
7.
Eilers, Benn J.
Microchannel steam-methane reforming under constant and variable surface temperature distributions.
Degree: MS, Mechanical Engineering, 2010, Oregon State University
URL: http://hdl.handle.net/1957/16395
► Steam-methane reforming is a well understood industrial process used for generating hydrogen and synthesis gas. The reaction is generally carried out with residence times on…
(more)
▼ Steam-methane reforming is a well understood industrial process used for generating hydrogen and synthesis gas. The reaction is generally carried out with residence times on the order of one second. By performing this reaction at microscales it is possible to take advantage of increased heat transfer rates and low diffusion times allowing equipment size and residence times to be decreased by an order of magnitude.
The energy required for the steam-methane reforming reaction could be supplied by solar energy through the use of a solar collector/receiver, thus providing a "cleaner" pathway for hydrogen generation. In such reactors, it is expected that the heat flux and temperature distribution is non-uniform. This study presents a first step in characterizing reforming performance under such variable temperature conditions. The design of the channel was such that the non-uniform heat flux profile expected inside of a solar receiver could be simulated by a controllable temperature profile along the reactor surface.
Experiments were conducted over four catalyst configurations and the effects of average reactor temperature, temperature distribution, residence time, steam-methane ratio, and long duration testing were all evaluated. Results demonstrated over 60% conversion of methane at 900°C and a residence time of 26 milliseconds. Methane conversion was found to be strongly dependent on reactor temperature. Ramping temperature distributions demonstrated a 46% greater hydrogen output than isothermal reactions performed at the same average temperature.
This work was performed in conjunction with development of a CFD model of reacting flow through a microchannel [1]. The experiments were used to determine the pre-exponential constants of the global reaction rates.
Advisors/Committee Members: Narayanan, Vinod (advisor), Schmitt, John (committee member).
Subjects/Keywords: Steam; Microreactors
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APA (6th Edition):
Eilers, B. J. (2010). Microchannel steam-methane reforming under constant and variable surface temperature distributions. (Masters Thesis). Oregon State University. Retrieved from http://hdl.handle.net/1957/16395
Chicago Manual of Style (16th Edition):
Eilers, Benn J. “Microchannel steam-methane reforming under constant and variable surface temperature distributions.” 2010. Masters Thesis, Oregon State University. Accessed April 15, 2021.
http://hdl.handle.net/1957/16395.
MLA Handbook (7th Edition):
Eilers, Benn J. “Microchannel steam-methane reforming under constant and variable surface temperature distributions.” 2010. Web. 15 Apr 2021.
Vancouver:
Eilers BJ. Microchannel steam-methane reforming under constant and variable surface temperature distributions. [Internet] [Masters thesis]. Oregon State University; 2010. [cited 2021 Apr 15].
Available from: http://hdl.handle.net/1957/16395.
Council of Science Editors:
Eilers BJ. Microchannel steam-methane reforming under constant and variable surface temperature distributions. [Masters Thesis]. Oregon State University; 2010. Available from: http://hdl.handle.net/1957/16395
Oregon State University
8.
Berberovic, Adin.
The impact of wood variability on the drying rate at different moisture content levels.
Degree: PhD, Wood Science, 2010, Oregon State University
URL: http://hdl.handle.net/1957/17702
► Variability in wood properties causes boards within a stack of lumber to dry at different rates and reach different moisture content levels after drying is…
(more)
▼ Variability in wood properties causes boards within a stack of lumber to
dry at different rates and reach different moisture content levels after drying is
completed. The consequence is that the boards will have properties that differ from
ones that were intended to be achieved by the drying process.
The impact of basic density, initial moisture content, percentage of
heartwood, position of heartwood within a board, ring count, distance from the
pith, growth ring angle, chemical composition of wood volatile compounds,
earlywood and latewood coverage of board faces on the drying behavior was
investigated for western hemlock (Tsuga heterophylla) lumber. Board weights
were monitored during drying at 80°C and 115°C to obtain the drying rate.
Mathematical relations for the effect of wood properties and board geometric
features related to the position within its parental log were developed to predict the
drying rate at four moisture content levels. These relations were used for
predicting the drying times of individual boards which were used as a criterion for
sorting green boards prior to drying.
Basic density, initial moisture content, heartwood percentage, and growth
ring angle were found to affect drying rate at 80°C and initial moisture content
only at 115°C. The calculated final moisture content distributions for nonpresorted
and presorted boards using the results from low temperature drying
indicated that presorting reduced the standard deviation of the final moisture
content distribution by 65%. The composition of head space volatiles appeared to
be predictive of the final moisture reached by boards and with further development
might be useful for presorting.
Advisors/Committee Members: Milota, Mike (advisor), Narayanan, Vinod (committee member).
Subjects/Keywords: Wood Drying; Western hemlock – Drying – Mathematical models
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APA (6th Edition):
Berberovic, A. (2010). The impact of wood variability on the drying rate at different moisture content levels. (Doctoral Dissertation). Oregon State University. Retrieved from http://hdl.handle.net/1957/17702
Chicago Manual of Style (16th Edition):
Berberovic, Adin. “The impact of wood variability on the drying rate at different moisture content levels.” 2010. Doctoral Dissertation, Oregon State University. Accessed April 15, 2021.
http://hdl.handle.net/1957/17702.
MLA Handbook (7th Edition):
Berberovic, Adin. “The impact of wood variability on the drying rate at different moisture content levels.” 2010. Web. 15 Apr 2021.
Vancouver:
Berberovic A. The impact of wood variability on the drying rate at different moisture content levels. [Internet] [Doctoral dissertation]. Oregon State University; 2010. [cited 2021 Apr 15].
Available from: http://hdl.handle.net/1957/17702.
Council of Science Editors:
Berberovic A. The impact of wood variability on the drying rate at different moisture content levels. [Doctoral Dissertation]. Oregon State University; 2010. Available from: http://hdl.handle.net/1957/17702
9.
King, Brian M. (Brian Matthew).
Natural circulation scaling of a pressurized conduction cooldown event in the upper plenum of the modular high temperature gas reactor.
Degree: MS, Nuclear Engineering, 2012, Oregon State University
URL: http://hdl.handle.net/1957/30342
► In a Modular High Temperature Gas Reactor (MHGTR), the Pressurized Conduction Cooldown (PCC) event is an accident scenario in which there is a loss of…
(more)
▼ In a Modular High Temperature Gas Reactor (MHGTR), the Pressurized Conduction Cooldown (PCC) event is an accident scenario in which there is a loss of forced convection of the coolant through the system but the pressure boundary remains intact. When the PCC event occurs, natural circulation onsets which results in a flow and temperature reversal, resulting in hot helium flowing into the upper plenum which could imping upon the upper plenum head. The High Temperature Test Facility (HTTF), which is being designed and constructed at
Oregon State University, is a scaled thermal test facility of the MHTGR which is being built for both code validation purposes and to examine specific flow phenomena of the gas reactor. This study is being performed to determine how the HTTF simulates the same conditions as the MHTGR under this scenario through the use of scaling parameters and computational fluid dynamics.
Advisors/Committee Members: Woods, Brian (advisor), Narayanan, Vinod (committee member).
Subjects/Keywords: Modular high temperature gas reactors; Gas cooled reactors – Cooling
…3
1-2: Oregon State University High Temperature Test Facility… …23
3-2: Oregon State University High Temperature Test Facility… …study is part of work done at Oregon State University (OSU) in collaboration with… …HTTF vessel can be seen in Figure 1-2.
Figure 1-2: Oregon State University High Temperature… …computer rendered model of the HTTF can be seen in Figure 3-2.
26
Figure 3-2: Oregon State…
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APA (6th Edition):
King, B. M. (. M. (2012). Natural circulation scaling of a pressurized conduction cooldown event in the upper plenum of the modular high temperature gas reactor. (Masters Thesis). Oregon State University. Retrieved from http://hdl.handle.net/1957/30342
Chicago Manual of Style (16th Edition):
King, Brian M (Brian Matthew). “Natural circulation scaling of a pressurized conduction cooldown event in the upper plenum of the modular high temperature gas reactor.” 2012. Masters Thesis, Oregon State University. Accessed April 15, 2021.
http://hdl.handle.net/1957/30342.
MLA Handbook (7th Edition):
King, Brian M (Brian Matthew). “Natural circulation scaling of a pressurized conduction cooldown event in the upper plenum of the modular high temperature gas reactor.” 2012. Web. 15 Apr 2021.
Vancouver:
King BM(M. Natural circulation scaling of a pressurized conduction cooldown event in the upper plenum of the modular high temperature gas reactor. [Internet] [Masters thesis]. Oregon State University; 2012. [cited 2021 Apr 15].
Available from: http://hdl.handle.net/1957/30342.
Council of Science Editors:
King BM(M. Natural circulation scaling of a pressurized conduction cooldown event in the upper plenum of the modular high temperature gas reactor. [Masters Thesis]. Oregon State University; 2012. Available from: http://hdl.handle.net/1957/30342
10.
Haley, David B. (David Brien).
Performance characterization of an integrated microscale hydrogen combustor recuperator and oil heat exchanger.
Degree: MS, Mechanical Engineering, 2011, Oregon State University
URL: http://hdl.handle.net/1957/21877
► Experiments on a novel, microscale hydrogen combustor heat exchanger (µCHX) are presented in this thesis. The µCHX has been designed to efficiently transfer thermal energy…
(more)
▼ Experiments on a novel, microscale hydrogen combustor heat exchanger (µCHX) are presented in this thesis. The µCHX has been designed to efficiently transfer thermal energy to a heat transfer fluid for use in desorption of hydrogen from a metal hydride storage system of a hydrogen-powered fuel cell vehicle. The experimental study demonstrates proof of concept for the design and examines the effect of varying selected fluidic and geometric conditions on the overall efficiency of the µCHX.
The small-scale device characterized in this thesis is a unit cell consisting of a combustion channel, a recuperator channel and an oil heat exchange channel. This unit cell device has the potential to be scaled up to a reactor in the tens of kilowatts range required for a vehicle scale system. Combusted gases flow back through the device in a counter-flow configuration between the combustion channel and the oil channel, preheating the inlet gas stream and transferring heat to the oil. Platinum has been selectively deposited on the stainless steel inner wall of the combustion channel to facilitate heterogeneous combustion of hydrogen and air. The performance of the µCHX is characterized based on a global efficiency, defined as the ratio of the energy transferred to the oil stream compared to the energy content of the supplied hydrogen gas.
The effects of residence time, equivalence ratio and average oil temperature have been investigated. Repeated testing of the catalyst over 80 hours indicated stable and repeatable results. Maximum hydrogen conversion in excess of 92 % was achieved for residence times greater than 20 ms at a stoichiometric equivalence ratio. Efficiencies above 90 % were obtained for equivalence ratios greater than 0.5 and for average oil temperatures between 63 °C and 105 °C. Experiments were conducted with catalyst deposited over 87 % and 20 % of the channel length. The longer catalyst demonstrated the highest efficiency and hydrogen conversion.
This work was performed concurrently with the development of a CFD model by Ghazvini and
Narayanan [1] with preliminary comparisons showed qualitatively good agreement. A preliminary design and financial analysis of a full size combustor was developed based on the demonstrated performance of the µCHX.
Advisors/Committee Members: Narayanan, Vinod (advisor), Brooks, Raymond (committee member).
Subjects/Keywords: Hydrogen
…collection of Oregon
State University libraries. My signature below authorizes release of my thesis…
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APA (6th Edition):
Haley, D. B. (. B. (2011). Performance characterization of an integrated microscale hydrogen combustor recuperator and oil heat exchanger. (Masters Thesis). Oregon State University. Retrieved from http://hdl.handle.net/1957/21877
Chicago Manual of Style (16th Edition):
Haley, David B (David Brien). “Performance characterization of an integrated microscale hydrogen combustor recuperator and oil heat exchanger.” 2011. Masters Thesis, Oregon State University. Accessed April 15, 2021.
http://hdl.handle.net/1957/21877.
MLA Handbook (7th Edition):
Haley, David B (David Brien). “Performance characterization of an integrated microscale hydrogen combustor recuperator and oil heat exchanger.” 2011. Web. 15 Apr 2021.
Vancouver:
Haley DB(B. Performance characterization of an integrated microscale hydrogen combustor recuperator and oil heat exchanger. [Internet] [Masters thesis]. Oregon State University; 2011. [cited 2021 Apr 15].
Available from: http://hdl.handle.net/1957/21877.
Council of Science Editors:
Haley DB(B. Performance characterization of an integrated microscale hydrogen combustor recuperator and oil heat exchanger. [Masters Thesis]. Oregon State University; 2011. Available from: http://hdl.handle.net/1957/21877
11.
Ghazvini, Mohammad.
Compact integrated microchannel combustor, recuperator and heat exchanger For hydrogen storage applications.
Degree: PhD, Mechanical Engineering, 2013, Oregon State University
URL: http://hdl.handle.net/1957/43337
► A novel microscale combustor-heat exchanger (μCHX) for hydrogen storage applications is presented in this dissertation. The design of the μCHX is motivated by its application…
(more)
▼ A novel microscale combustor-heat exchanger (μCHX) for hydrogen storage applications is presented in this dissertation. The design of the μCHX is motivated by its application to two particular systems for automotive use- those that utilize metal hydrides (MH) and cryo-adsorbents (CA) to store hydrogen. Thermal energy needs to be supplied to the MH bed to raise its temperature to 170 °C in order to desorb hydrogen for use in a fuel cell. On the other hand, in a CA system, hydrogen gas that exits the storage tank needs to be heated to a minimum temperature of -40 °C prior to entering the fuel cell. During cold start conditions, heat exchange with ambient air or with the fuel cell coolant is insufficient to provide this minimum temperature, thereby requiring an additional source of thermal energy. For both storage systems, the required thermal energy can be provided by oxidizing a small amount of hydrogen and transferring the heat from combustion to the working fluid, which is an oil in a MH system and hydrogen in a CA system. The μCHX presented herein is a compact and highly efficient way of providing the required thermal energy rate. The µCHX is comprised of repeating unit cells that each perform identical unit operations, namely (a) catalytic combustion of a hydrogen-air mixture, (b) transfer of produced thermal energy rate to a heat transfer fluid, and (c) recuperation between the exhaust gas stream and incoming reactant gases. Heterogeneous catalytic combustion occurs on the walls of microchannels in the presence of a platinum catalyst. A multi-kilowatt µCHX device can be achieved by having multiple unit cells with appropriate fluidic distribution headers. The µCHX design is common for both hydrogen storage systems with minor changes. The design of the µCHX is performed using computational fluid dynamics simulations (CFD) at the unit cell and device level. At the unit cell level, the performance is documented using validated CFD simulations for variations in geometric and fluidic parameters. Varied geometric parameters include the length and location of the catalyst bed, length of the device, and the height of the combustion channel. Varied fluidic parameters include the working fluid inlet temperature, flow rates of the working fluid and reactants, and the equivalence ratio of the reactants. Performance is characterized using a global efficiency, heat transfer effectiveness and hydrogen conversion. The parametric variations are captured non-dimensionally as variations in Damkohler and Peclet numbers, which are in turn used to describe the changes in hydrogen conversion and efficiency. Performance maps for hydrogen conversion and pressure drop in the combustion channel are presented based on values of the Damkohler and Peclet numbers and regions of desired operability of the combustor are identified. For the CA µCHX, it is shown that with the help of a novel distributed catalyst arrangement, extinction of the reaction due to the cold gas stream is prevented and hydrogen conversion in excess of 95 percent is…
Advisors/Committee Members: Narayanan, Vinod (advisor), Apte, Sourabh (committee member).
Subjects/Keywords: Microchannel; Hydrogen as fuel
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APA (6th Edition):
Ghazvini, M. (2013). Compact integrated microchannel combustor, recuperator and heat exchanger For hydrogen storage applications. (Doctoral Dissertation). Oregon State University. Retrieved from http://hdl.handle.net/1957/43337
Chicago Manual of Style (16th Edition):
Ghazvini, Mohammad. “Compact integrated microchannel combustor, recuperator and heat exchanger For hydrogen storage applications.” 2013. Doctoral Dissertation, Oregon State University. Accessed April 15, 2021.
http://hdl.handle.net/1957/43337.
MLA Handbook (7th Edition):
Ghazvini, Mohammad. “Compact integrated microchannel combustor, recuperator and heat exchanger For hydrogen storage applications.” 2013. Web. 15 Apr 2021.
Vancouver:
Ghazvini M. Compact integrated microchannel combustor, recuperator and heat exchanger For hydrogen storage applications. [Internet] [Doctoral dissertation]. Oregon State University; 2013. [cited 2021 Apr 15].
Available from: http://hdl.handle.net/1957/43337.
Council of Science Editors:
Ghazvini M. Compact integrated microchannel combustor, recuperator and heat exchanger For hydrogen storage applications. [Doctoral Dissertation]. Oregon State University; 2013. Available from: http://hdl.handle.net/1957/43337
12.
Jo, Myeong Chan.
Thermally actuated pumping of a single-phase fluid using surface asymmetry.
Degree: MS, Mechanical Engineering, 2008, Oregon State University
URL: http://hdl.handle.net/1957/9004
► An experimental study of thermally actuated pumping of a single-phase, single-component fluid is presented in the context of thermal management of a heat source. The…
(more)
▼ An experimental study of thermally actuated pumping of a single-phase, single-component fluid is presented in the context of thermal management of a heat source. The prominent feature of this pumping method is that the very heat that is to be removed from the heat source causes a net fluid motion. Therefore, such a thermal management system tends to be passive and noiseless. The dominant driving force for
convection in this study is surface tension. An asymmetry in this force is created by the use of a surface with repeated asymmetric triangular structures.
Silicone oil was used as the working fluid. Independent parameters consisted of the
channel surface-to-ambient temperature difference and the fluid thickness. A dye-tracking imaging method was developed to determine the fluid interfacial velocity.
The flow results were corroborated with interfacial temperature measurements
obtained using infrared thermography.
Dye tracking experiments indicate that the direction of net fluid motion is from the less-steep side of the ratchet towards its steeper side, resulting in a clockwise flow direction in the closed loop channel for all three liquid depths of 0.5 mm, 1.0 mm and 2.7 mm. The range of the net flow velocities varies from 0.18 mm/min to 0.86
mm/min. A fluid height of 1 mm results in a maximum net fluid velocity at both surface-to-ambient temperatures studied. Interfacial temperature contour maps
indicate the presence of thermal structures that are indicative of convection cells, and
that an optimum thickness exists for maximum heat transfer coefficient. Difference in streamwise gradients of temperature (and hence surface tension) on either side of the thermal structures causes a net streamwise surface tension gradient in the direction of net fluid motion. An optimal fluid thickness for heat transfer as well as net interfacial fluid velocity is suggested by the results.
Advisors/Committee Members: Narayanan, Vinod (advisor), Pence, Deborah (committee member).
Subjects/Keywords: Marangoni convection; Integrated circuits – Cooling
…THESIS
submitted to
Oregon State University
in partial fulfillment of
the requirements for the… …collection of Oregon
State University libraries. My signature below authorizes release of my thesis… …and encouragement throughout the course of this study at
Oregon State University. The…
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APA (6th Edition):
Jo, M. C. (2008). Thermally actuated pumping of a single-phase fluid using surface asymmetry. (Masters Thesis). Oregon State University. Retrieved from http://hdl.handle.net/1957/9004
Chicago Manual of Style (16th Edition):
Jo, Myeong Chan. “Thermally actuated pumping of a single-phase fluid using surface asymmetry.” 2008. Masters Thesis, Oregon State University. Accessed April 15, 2021.
http://hdl.handle.net/1957/9004.
MLA Handbook (7th Edition):
Jo, Myeong Chan. “Thermally actuated pumping of a single-phase fluid using surface asymmetry.” 2008. Web. 15 Apr 2021.
Vancouver:
Jo MC. Thermally actuated pumping of a single-phase fluid using surface asymmetry. [Internet] [Masters thesis]. Oregon State University; 2008. [cited 2021 Apr 15].
Available from: http://hdl.handle.net/1957/9004.
Council of Science Editors:
Jo MC. Thermally actuated pumping of a single-phase fluid using surface asymmetry. [Masters Thesis]. Oregon State University; 2008. Available from: http://hdl.handle.net/1957/9004
13.
Cardenas, Ruander.
Submerged jet impingement boiling thermal management.
Degree: PhD, Mechanical Engineering, 2011, Oregon State University
URL: http://hdl.handle.net/1957/23702
► Technologies such as avionics and power electronics are driving the demand for thermal management schemes towards high heat fluxes and low surface temperatures. Typically, these…
(more)
▼ Technologies such as avionics and power electronics are driving the demand for thermal management schemes towards high heat fluxes and low surface temperatures. Typically, these applications require the dissipation of heat fluxes in the rage of 100-1000 W/cm² while maintaining surface temperatures lower than about 85 °C. Phase-change heat transfer schemes such as pool boiling, flow boiling in mini/micro-channel heat sinks, and sprays and jet impingement boiling are frequently used to meet this demand. This dissertation documents global heat transfer characteristics of submerged jet impingement boiling for high heat flux, low surface temperature applications. The effect of geometrical and flow parameters on heat transfer performance are examined for a single circular jet using water and FC-72 as working fluids. Exclusive to this
study is the comparison of distinct jet fluids at a fixed saturation temperature, which is achieved by comparing sub-atmospheric jet impingement boiling data of water with atmospheric FC-72 experiments. Under sub-atmospheric conditions, the liquid-to-vapor density ratio of water is within a range that has not been studied in previous jet impingement boiling experiments. Varied geometrical parameters include the surface-to-nozzle diameter ratio, surface roughness, and jet configuration. Varied fluidic parameters include pressure, jet exit Reynolds number, fluid subcooling, and fluid properties. Global experimental data collected during this study are used to document the relationship between surface temperature and surface heat flux through boiling curves. The global data are augmented by qualitative high-speed visualization.
Experimental data demonstrate enhanced heat transfer capabilities beyond those of pool boiling by using a submerged impinging jet. For a fixed saturation temperature, significantly higher heat transfer rates are attainable using water in comparison to FC-72. A CHF map for submerged jet impingement boiling is developed based on experimental evidence. A general submerged jet impingement CHF correlation is developed based on a well known CHF model in literature. A novel, passive means of preventing temperature overshoot of highly-wetting fluids during submerged jet impingement boiling is introduced.
Advisors/Committee Members: Narayanan, Vinod (advisor), Apte, Sourabh V. (committee member).
Subjects/Keywords: jet impingement boiling; Electronic apparatus and appliances – Cooling
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APA (6th Edition):
Cardenas, R. (2011). Submerged jet impingement boiling thermal management. (Doctoral Dissertation). Oregon State University. Retrieved from http://hdl.handle.net/1957/23702
Chicago Manual of Style (16th Edition):
Cardenas, Ruander. “Submerged jet impingement boiling thermal management.” 2011. Doctoral Dissertation, Oregon State University. Accessed April 15, 2021.
http://hdl.handle.net/1957/23702.
MLA Handbook (7th Edition):
Cardenas, Ruander. “Submerged jet impingement boiling thermal management.” 2011. Web. 15 Apr 2021.
Vancouver:
Cardenas R. Submerged jet impingement boiling thermal management. [Internet] [Doctoral dissertation]. Oregon State University; 2011. [cited 2021 Apr 15].
Available from: http://hdl.handle.net/1957/23702.
Council of Science Editors:
Cardenas R. Submerged jet impingement boiling thermal management. [Doctoral Dissertation]. Oregon State University; 2011. Available from: http://hdl.handle.net/1957/23702
14.
Bowser, Christopher Jordan.
RELAP5-3D modeling of ADS blowdown of MASLWR facility.
Degree: MS, Nuclear Engineering, 2012, Oregon State University
URL: http://hdl.handle.net/1957/30438
► Oregon State University has hosted an International Atomic Energy Agency (IAEA) International Collaborative Standard Problem (ICSP) through testing conducted on the Multi-Application Small Light Water…
(more)
▼ Oregon State University has hosted an International Atomic Energy Agency (IAEA)
International Collaborative Standard Problem (ICSP) through testing conducted on the
Multi-Application Small Light Water (MASLWR) facility. The MASLWR facility features
a full-time natural circulation loop in the primary vessel and a unique pressure suppression
device for accident scenarios. Automatic depressurization system (ADS) lines connect
the primary vessel to a high pressure containment (HPC) which dissipates steam heat
through a heat transfer plate thermally connected to another vessel with a large cool
water inventory. This feature drew the interest of the IAEA and an ICSP was developed
where a loss of feedwater to the steam generators prompted a depressurization of the
primary vessel via a blowdown through the ADS lines.
The purpose of the ICSP is to evaluate the applicability of thermal-hydraulic computer
codes to unique experiments usually outside of the validation matrix of the code
itself. RELAP5-3D 2:4:2 was chosen to model the ICSP. RELAP5-3D is a best-estimate
code designed to simulate transient
fluid and thermal behavior in light water reactors.
Modeling was conducted in RELAP5-3D to identify the strengths and weaknesses of the
code in predicting the experimental trends of the IAEA ICSP. This extended to nodalization
sensitivity studies, an investigation of built-in models and heat transfer boundary
conditions. Besides a qualitative analysis, a quantitative analysis method was also performed.
Advisors/Committee Members: Woods, Brian G. (advisor), Narayanan, Vinod (committee member).
Subjects/Keywords: Nuclear; Light water reactors – Safety measures
…will become part of the permanent collection of Oregon State
University libraries. My… …Light Water Reactor (MASLWR) facility at Oregon State University (OSU)…
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APA (6th Edition):
Bowser, C. J. (2012). RELAP5-3D modeling of ADS blowdown of MASLWR facility. (Masters Thesis). Oregon State University. Retrieved from http://hdl.handle.net/1957/30438
Chicago Manual of Style (16th Edition):
Bowser, Christopher Jordan. “RELAP5-3D modeling of ADS blowdown of MASLWR facility.” 2012. Masters Thesis, Oregon State University. Accessed April 15, 2021.
http://hdl.handle.net/1957/30438.
MLA Handbook (7th Edition):
Bowser, Christopher Jordan. “RELAP5-3D modeling of ADS blowdown of MASLWR facility.” 2012. Web. 15 Apr 2021.
Vancouver:
Bowser CJ. RELAP5-3D modeling of ADS blowdown of MASLWR facility. [Internet] [Masters thesis]. Oregon State University; 2012. [cited 2021 Apr 15].
Available from: http://hdl.handle.net/1957/30438.
Council of Science Editors:
Bowser CJ. RELAP5-3D modeling of ADS blowdown of MASLWR facility. [Masters Thesis]. Oregon State University; 2012. Available from: http://hdl.handle.net/1957/30438
15.
Mani, Preeti.
Local heat transfer rate and bubble dynamics during jet impingement boiling.
Degree: PhD, Mechanical Engineering, 2012, Oregon State University
URL: http://hdl.handle.net/1957/35039
► Characterization of local boiling trends, in addition to the typically reported area-averaged trends, is essential for the robust design and implementation of phase change technologies…
(more)
▼ Characterization of local boiling trends, in addition to the typically reported area-averaged trends, is essential for the robust design and implementation of phase change technologies to sensitive heat transfer applications such as electronics cooling. Obtaining the values of heat fluxes corresponding to locally varying surface temperatures has been a challenge limiting most investigations to area-averaged results. This thesis illustrates the importance of a spatially local heat transfer analysis during boiling.
Pool and submerged jet impingement boiling scenarios on a silicon surface are considered at the macroscale (27.5 mm heater with multiple nucleation sites) and microscale (1000 μm heater for isolated bubble generation), by the use of two thin film serpentine heater geometries. The macroscale heater highlights the effect of spatial variations in imposed heat flux on boiling heat transfer with a circumferentially uniform but radially non-uniform heat flux distribution. The microscale heater simulates a local hot-spot for spot cooling on an electronic device.
Spatial variation in boiling heat transfer and bubble dynamics with and without a jet flow are documented using thin film voltage sensors along with qualitative and quantitative high speed imaging and infra-red thermography. Unique to this study is the documentation of local boiling curves for different radial locations on the heat transfer surface and their comparison with the corresponding area-averaged representations. It is shown here that sectionally averaged representations of boiling curves over regions of like-imposed heat flux can substantially simplify the interpretation of data while retaining important information of the local variations in heat transfer.
The radial influence of the convective jet flow on the bubble dynamics and boiling heat transfer is assessed for a single circular submerged jet configuration. Varied parameters include jet exit Reynolds numbers, nozzle geometry, test fluid (deionized water and FC-72), fluid subcooling and the supplied heat flux. Distinct modifications of the surface temperature distribution imposed by the impinging jet flow are highlighted by comparing radial temperature profiles during pool and jet impingement boiling. It is demonstrated that in contrast with pool boiling, thermal overshoots during jet impingement boiling for a highly wetting fluid like FC-72 are highest in regions farthest from the impingement point.
The effect of jet inertia on bubble departure characteristics are compared with pool boiling under subcooled conditions for FC-72. Qualitative high speed visualization indicates the presence of two modes of bubble generation during jet impingement boiling (a) bubble departure from the surface and (b) bubble separation from the source resulting in sliding bubbles over the surface. The effect of jet flow on bubble entrainment is depicted. Quantitative results indicate that in general departure diameters for pool and jet impingement boiling increase and plateau at a maximum value with…
Advisors/Committee Members: Narayanan, Vinod (advisor), Liburdy, James A. (committee member).
Subjects/Keywords: Jet impingement boiling; Electronic apparatus and appliances – Cooling
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APA (6th Edition):
Mani, P. (2012). Local heat transfer rate and bubble dynamics during jet impingement boiling. (Doctoral Dissertation). Oregon State University. Retrieved from http://hdl.handle.net/1957/35039
Chicago Manual of Style (16th Edition):
Mani, Preeti. “Local heat transfer rate and bubble dynamics during jet impingement boiling.” 2012. Doctoral Dissertation, Oregon State University. Accessed April 15, 2021.
http://hdl.handle.net/1957/35039.
MLA Handbook (7th Edition):
Mani, Preeti. “Local heat transfer rate and bubble dynamics during jet impingement boiling.” 2012. Web. 15 Apr 2021.
Vancouver:
Mani P. Local heat transfer rate and bubble dynamics during jet impingement boiling. [Internet] [Doctoral dissertation]. Oregon State University; 2012. [cited 2021 Apr 15].
Available from: http://hdl.handle.net/1957/35039.
Council of Science Editors:
Mani P. Local heat transfer rate and bubble dynamics during jet impingement boiling. [Doctoral Dissertation]. Oregon State University; 2012. Available from: http://hdl.handle.net/1957/35039
16.
Rymal, Charles.
Numerical design of a high-flux microchannel solar receiver.
Degree: MS, Mechanical Engineering, 2014, Oregon State University
URL: http://hdl.handle.net/1957/54897
► This thesis discusses the design of several microchannel solar receiver devices for use in CSP (concentrated solar power) using CFD (computational fluid dynamics) simulations. The…
(more)
▼ This thesis discusses the design of several microchannel solar receiver devices for use in CSP (concentrated solar power) using CFD (computational fluid dynamics) simulations. The goal is to demonstrate that, by taking advantage of the higher heat transfer coefficienct of microchannels, solar receivers can achieve higher efficiency than current receiver technology, reducing the cost of solar thermal power. Design using CFD simulations is necessary in order to estimate the performance of different designs and identify potential issues before investing in a real device. The lack of previous research into such devices is most likely due to challenges concerning (a) the manufacturing of microchannels in materials that are suited to the high temperature and stress of the application and (b) the design of a headering system for a large scale implementation. Both supercritical carbon-dioxide and molten salt are used as heat-transfer fluids. The required inlet and outlet temperatures of the fluid are 773 K and 923 K for carbon-dioxide and 573 K and 873 K for molten salt. These values are determined by the CSP application and the properties of the fluids. Designs presented range in size from 1 cm² to 4 cm² and in heat transfer rates from 200 W to 400 W. These values are determined by the capacity of the solar simulator, which will be used for testing. For carbon-dioxide, three designs are developed with varying manufacturability. The high risk design features a circular micro-pin-fin array created using chemical etching and is constructed using diffusion bonding. The low risk design features machined and welded parts and parallel circular channels. The medium risk design features machined and diffusion bonded parts and parallel rectangular channels. For molten salt, two designs are developed: one using parallel rectangular channels and one using a circular pin-fin array. Conjugate CFD simulations of each design are used to evaluate pressure drop, receiver efficiency, and flow distribution. Two- and three-dimensional structural analyses are used to ensure that the devices will withstand the mechanical and thermal stress. An efficiency of 89.7%, pressure drop of 0.2 bar, and structural safety factor of 1.3 was achieved for carbon-dioxide. An efficiency of 92.1%, pressure drop of 0.5 bar, and structural safety factor of 2.5 was achieved for molten salt. The results demonstrate that microchannel devices can withstand the high flux, temperature, and stress of a CSP appliction and have high efficiency. However, additional work is needed before these designs can be implemented on a large scale.
Advisors/Committee Members: Apte, Sourabh V. (advisor), Narayanan, Vinod (committee member).
Subjects/Keywords: microchannel; Microreactors – Design and construction
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APA (6th Edition):
Rymal, C. (2014). Numerical design of a high-flux microchannel solar receiver. (Masters Thesis). Oregon State University. Retrieved from http://hdl.handle.net/1957/54897
Chicago Manual of Style (16th Edition):
Rymal, Charles. “Numerical design of a high-flux microchannel solar receiver.” 2014. Masters Thesis, Oregon State University. Accessed April 15, 2021.
http://hdl.handle.net/1957/54897.
MLA Handbook (7th Edition):
Rymal, Charles. “Numerical design of a high-flux microchannel solar receiver.” 2014. Web. 15 Apr 2021.
Vancouver:
Rymal C. Numerical design of a high-flux microchannel solar receiver. [Internet] [Masters thesis]. Oregon State University; 2014. [cited 2021 Apr 15].
Available from: http://hdl.handle.net/1957/54897.
Council of Science Editors:
Rymal C. Numerical design of a high-flux microchannel solar receiver. [Masters Thesis]. Oregon State University; 2014. Available from: http://hdl.handle.net/1957/54897
17.
Strid, Logan.
Passive pumping in pool and open channel configurations via meso-scale asymmetric surface patterning.
Degree: MS, Mechanical Engineering, 2013, Oregon State University
URL: http://hdl.handle.net/1957/43253
► The research presented in this thesis is a continuation of collaboration between Oregon State University and Auburn University studying the feasibility of passively pumping liquid…
(more)
▼ The research presented in this thesis is a continuation of collaboration between
Oregon State University and Auburn
University studying the feasibility of passively pumping liquid during boiling in a preferential direction using meso-scaled asymmetric surface patterns. Such a passive phase-change mechanism has great potential for thermal management in spacecraft and in zero-gravity environments. Fluid pumping is demonstrated in two configurations – one in which the patterned surface is immersed in a pool of liquid, and a second in which two patterned surfaces form the vertical walls of an open channel. The surface pattern consists of 60-30 degree millimeter scale ratchets. In the pool configuration, ratchets have a cavity on the 30 degree slope of the ratchets for preferential nucleation. In the pool configuration, the asymmetric geometry causes bubbles to preferentially grow normal to the surface rather than in a vertical direction. A semi-empirical model predicting resultant liquid velocities is validated with particle tracking velocimetry. A single bubble was found to have an area of influence on the surrounding liquid equal to the average projected area of the bubbles during its growth cycle and was capable of imparting average fluid velocities of 75 mm¹s⁻¹ at an angle 32.7° from vertical. In the open channel configuration, high-speed videos document the dramatic preferential motion of vapor slugs with velocities ranging from 13.4 mm¹s⁻¹ to 96.3 mm¹s⁻¹ under both diabatic and flash boiling conditions. Four regimes of channel flow are identified and bubble kinematics is presented. A thin liquid film is observed to exist in between the ratchet wall and the vapor slug. A model to determine slug velocities based on a balance of the net Young-Laplace pressure gradient in the thin liquid film and the viscous drag of the channel walls is put forth.
Advisors/Committee Members: Narayanan, Vinod (advisor), Pence, Deborah V. (committee member).
Subjects/Keywords: Boiling; Pumping machinery – Fluid dynamics
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APA (6th Edition):
Strid, L. (2013). Passive pumping in pool and open channel configurations via meso-scale asymmetric surface patterning. (Masters Thesis). Oregon State University. Retrieved from http://hdl.handle.net/1957/43253
Chicago Manual of Style (16th Edition):
Strid, Logan. “Passive pumping in pool and open channel configurations via meso-scale asymmetric surface patterning.” 2013. Masters Thesis, Oregon State University. Accessed April 15, 2021.
http://hdl.handle.net/1957/43253.
MLA Handbook (7th Edition):
Strid, Logan. “Passive pumping in pool and open channel configurations via meso-scale asymmetric surface patterning.” 2013. Web. 15 Apr 2021.
Vancouver:
Strid L. Passive pumping in pool and open channel configurations via meso-scale asymmetric surface patterning. [Internet] [Masters thesis]. Oregon State University; 2013. [cited 2021 Apr 15].
Available from: http://hdl.handle.net/1957/43253.
Council of Science Editors:
Strid L. Passive pumping in pool and open channel configurations via meso-scale asymmetric surface patterning. [Masters Thesis]. Oregon State University; 2013. Available from: http://hdl.handle.net/1957/43253
Oregon State University
18.
Patil, Vishal.
Application of infrared thermography for temperature measurement in microscale internal and external flows.
Degree: MS, Mechanical Engineering, 2005, Oregon State University
URL: http://hdl.handle.net/1957/22411
► Infrared (IR) thermography is applied to estimate heat transfer rates in external and internal microscale convective flows. The technique and analysis are developed in the…
(more)
▼ Infrared (IR) thermography is applied to estimate heat transfer rates in external and internal microscale convective flows. The technique and analysis are developed in the context of external jet impingement flow and internal single-phase liquid flows. A heated-thin-foil thermography technique is applied to perform surface temperature visualization on a submerged 125-[mu]m circular microscale jet impingement. Microscale jets flows are associated with low exit Reynolds number (Re) due to the small characteristic length of the nozzle, but correspondingly high exit
velocities, and hence, a high subsonic Mach number. Detailed distributions of heated and adiabatic wall temperature, and local and average Nusselt number (Nu) variations are presented for a single 125-[mu]m diameter air jet impingement for five laminar exit Re in the range of 690 to 1770 at three nozzle-to-surface spacing of 2, 4, and 6 times the nozzle diameter. The corresponding jet exit Mach numbers vary between 0.26 and 0.63. Lateral heat conduction along the impingement surface is significant and warrants inclusion in the calculation of heat transfer coefficient. Results indicate that the adiabatic surface temperature distribution is relatively insensitive to nozzle-to-surface spacing within the parameter range studied. With an increase in Re, the adiabatic surface temperature decreases significantly near the stagnation point. The
average Nu is higher compared to the turbulent macroscale Martin's correlation for large Re.
A technique for quantitative temperature visualization of single-phase liquid flows in silicon (Si) microchannels using infrared thermography is presented. This technique offers a new way to measure, non-intrusively, local variations in wall temperature, or fluid temperature at the fluid-wall interface, in a microchannel fabricated entirely of silicon. The experimental setup and measurement procedure required to obtain high signal-to-noise ratio is elaborated. A single 13-mm long, 50 [mu]m wide by 135 [mu]m deep Si microchannel was used in this study. Experiments were performed with a constant electrical heat input rate to the heat sink surface for four fluid flow rates between 0.6 g/min and 1.2 g/min, corresponding to a Re range from 200 to 300. The estimated experimental fully developed Nu compares reasonably well with the solution provided in literature for laminar flows. Results indicate that axial non-uniformity can be significant for the large Peclet number flows.
Advisors/Committee Members: Narayanan, Vinod (advisor).
Subjects/Keywords: Heat – Transmission – Measurement
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APA (6th Edition):
Patil, V. (2005). Application of infrared thermography for temperature measurement in microscale internal and external flows. (Masters Thesis). Oregon State University. Retrieved from http://hdl.handle.net/1957/22411
Chicago Manual of Style (16th Edition):
Patil, Vishal. “Application of infrared thermography for temperature measurement in microscale internal and external flows.” 2005. Masters Thesis, Oregon State University. Accessed April 15, 2021.
http://hdl.handle.net/1957/22411.
MLA Handbook (7th Edition):
Patil, Vishal. “Application of infrared thermography for temperature measurement in microscale internal and external flows.” 2005. Web. 15 Apr 2021.
Vancouver:
Patil V. Application of infrared thermography for temperature measurement in microscale internal and external flows. [Internet] [Masters thesis]. Oregon State University; 2005. [cited 2021 Apr 15].
Available from: http://hdl.handle.net/1957/22411.
Council of Science Editors:
Patil V. Application of infrared thermography for temperature measurement in microscale internal and external flows. [Masters Thesis]. Oregon State University; 2005. Available from: http://hdl.handle.net/1957/22411
Oregon State University
19.
Fackrell, Kurt.
Flow boiling of lithium bromide-water solution in microchannels, with application to desorption.
Degree: MS, Mechanical Engineering, 2004, Oregon State University
URL: http://hdl.handle.net/1957/22730
► Recent studies of flow boiling within microchannels have shown high heat fluxes, leading to successful design and testing of compact heat exchangers, cooling systems for…
(more)
▼ Recent studies of flow boiling within microchannels have shown high heat fluxes,
leading to successful design and testing of compact heat exchangers, cooling systems
for electronics and other high efficiency, miniature components. An experimental
study of flow boiling of a concentrated salt solution in microchannels is presented.
Experiments examined flow in single, circular microchannels, with a length of 25 mm
and diameters of 0.127 mm and 0.25 mm, and in arrays of five rectangular
microchannels, each with a length of 8.5 mm and a hydraulic diameter of 0.133 mm.
Inlet concentrations of lithium bromide were varied from 47% to 57% by mass, heat
inputs from 2.2 to 7.0 W per channel, and flow rates from 0.60 to 0.80 g/min per
channel. Single channel tests yielded as much as 0.05 g/min of water vapor for the
conditions examined. If an array of channels could produce vapor at a similar rate, it
may be possible to apply microchannel flow boiling in a compact desorber or
evaporator. Unequal flow distribution in the microchannel arrays limited testing to
heat input rates too low to verify array desorption.
Infrared visualization of flow at the exit of the microchannel was performed to
document solution exit condition based on flow rate, heat input rate, and lithium
bromide concentration. Visualization identified four basic exit conditions: steady
dripping at low heat input rates, unsteady dripping with occasional vapor at moderate
heat input rates, continuous droplet spraying at high heat input rates and flow rates,
and long period oscillation between unsteady dripping and droplet spraying at high
heat input rates and low flow rates.
Advisors/Committee Members: Narayanan, Vinod (advisor).
Subjects/Keywords: Microfluidics
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APA (6th Edition):
Fackrell, K. (2004). Flow boiling of lithium bromide-water solution in microchannels, with application to desorption. (Masters Thesis). Oregon State University. Retrieved from http://hdl.handle.net/1957/22730
Chicago Manual of Style (16th Edition):
Fackrell, Kurt. “Flow boiling of lithium bromide-water solution in microchannels, with application to desorption.” 2004. Masters Thesis, Oregon State University. Accessed April 15, 2021.
http://hdl.handle.net/1957/22730.
MLA Handbook (7th Edition):
Fackrell, Kurt. “Flow boiling of lithium bromide-water solution in microchannels, with application to desorption.” 2004. Web. 15 Apr 2021.
Vancouver:
Fackrell K. Flow boiling of lithium bromide-water solution in microchannels, with application to desorption. [Internet] [Masters thesis]. Oregon State University; 2004. [cited 2021 Apr 15].
Available from: http://hdl.handle.net/1957/22730.
Council of Science Editors:
Fackrell K. Flow boiling of lithium bromide-water solution in microchannels, with application to desorption. [Masters Thesis]. Oregon State University; 2004. Available from: http://hdl.handle.net/1957/22730
Oregon State University
20.
Jenks, Jeromy W.
An experimental study of ammonia-water bubble absorption in a constrained microscale film.
Degree: MS, Mechanical Engineering, 2007, Oregon State University
URL: http://hdl.handle.net/1957/6350
► An experimental study of absorption of ammonia into a constrained thin film of ammonia-water solution is presented. A large aspect ratio microchannel with one of…
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▼ An experimental study of absorption of ammonia into a constrained thin film of ammonia-water solution is presented. A large aspect ratio microchannel with one of its walls formed by a porous material is used to constrain the thickness of the liquid film. Experiments were performed at a pressure of 1, 2.5 and 4 bar absolute and a fixed weak solution inlet temperature. Weak solution flow rates were varied from 10 to 30 g/min, inlet mass concentrations from 0 to 15 percent, and gas flow rates between 1 and 3 g/min. Six geometries, including three smooth-bottom-walled channels of differing depths and three channels with structured bottom walls are considered. Results indicate that for identical rates of vapor absorption, the overall heat transfer coefficient for the 400 um smooth microchannel is significantly larger than of the 150 um and 1500 um smooth channels. For the 150 um channel, the largest overall heat and mass transfer coefficients were achieved for the highest vapor to solution flow rate ratio, where the ratio of heat generated to heat removed was unity.
A numerical model is also presented that predicts temperature and concentration profiles along the length of the absorber. In the present
state, the model is not adequate for realistic sizing due to assuming instantaneous absorption of ammonia vapor. An updated model is proposed that accounts for local mass transfer phenomena that accounts for bubble size reduction and eventual absorption.
Finally, sizing estimates are introduced by scaling up the absorber using the highest flow rate ratio case, 3/10. The magnitude of the scale is dependent upon the application (residential or vehicular). Absorber dimensions for a vehicle are estimated at 4 cm x 14 cm x 28 cm, and the residential absorber dimensions, 4 cm x 29 cm x 58 cm.
Advisors/Committee Members: Narayanan, Vinod (advisor), Kanury, Murty (committee member).
Subjects/Keywords: Microscale; Absorption – Mathematical models
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APA (6th Edition):
Jenks, J. W. (2007). An experimental study of ammonia-water bubble absorption in a constrained microscale film. (Masters Thesis). Oregon State University. Retrieved from http://hdl.handle.net/1957/6350
Chicago Manual of Style (16th Edition):
Jenks, Jeromy W. “An experimental study of ammonia-water bubble absorption in a constrained microscale film.” 2007. Masters Thesis, Oregon State University. Accessed April 15, 2021.
http://hdl.handle.net/1957/6350.
MLA Handbook (7th Edition):
Jenks, Jeromy W. “An experimental study of ammonia-water bubble absorption in a constrained microscale film.” 2007. Web. 15 Apr 2021.
Vancouver:
Jenks JW. An experimental study of ammonia-water bubble absorption in a constrained microscale film. [Internet] [Masters thesis]. Oregon State University; 2007. [cited 2021 Apr 15].
Available from: http://hdl.handle.net/1957/6350.
Council of Science Editors:
Jenks JW. An experimental study of ammonia-water bubble absorption in a constrained microscale film. [Masters Thesis]. Oregon State University; 2007. Available from: http://hdl.handle.net/1957/6350
Oregon State University
21.
Thirunavukarasu, Balamurugesh.
A study of solidification dynamics with liquid mass influx.
Degree: MS, Mechanical Engineering, 2003, Oregon State University
URL: http://hdl.handle.net/1957/31591
► A computational model is developed to study the effects of alumina layer formation on an ablative surface when exposed to high temperature particle laden gas…
(more)
▼ A computational model is developed to study the effects of alumina layer formation
on an ablative surface when exposed to high temperature particle laden gas
flow. The solidification dynamics i.e., the solid and liquid alumina layer growth rate,
and the heat transferred to the ablative surface are investigated. A one-dimensional
model is developed taking into consideration the thermal loading, particle loading
and the temperature dependence of the thermo-physical properties of alumina. A
fully implicit finite volume method is used to solve the coupled set of non-linear heat
conduction equations. The solidification interface is tracked using the Lagrangian
interpolation technique. The particle mass flux was found to be the major factor
affecting the solid layer growth rate. The gas heat flux also has a major effect on
the solid growth rate and the heat transferred to the ablative surface, but only for
lower particle mass fluxes. On other hand the particle temperature has a linear
effect on the solidification dynamics and the heat transferred to the ablative surface
for all particle mass fluxes. The heat transferred to the ablative surface is reduced
by approximately 39% to 88%, depending on the mass fluxes, due to the formation
of the alumina layer.
Advisors/Committee Members: Liburdy, James A. (advisor), Narayanan, Vinod (committee member).
Subjects/Keywords: Solidification – Mathematical models
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APA (6th Edition):
Thirunavukarasu, B. (2003). A study of solidification dynamics with liquid mass influx. (Masters Thesis). Oregon State University. Retrieved from http://hdl.handle.net/1957/31591
Chicago Manual of Style (16th Edition):
Thirunavukarasu, Balamurugesh. “A study of solidification dynamics with liquid mass influx.” 2003. Masters Thesis, Oregon State University. Accessed April 15, 2021.
http://hdl.handle.net/1957/31591.
MLA Handbook (7th Edition):
Thirunavukarasu, Balamurugesh. “A study of solidification dynamics with liquid mass influx.” 2003. Web. 15 Apr 2021.
Vancouver:
Thirunavukarasu B. A study of solidification dynamics with liquid mass influx. [Internet] [Masters thesis]. Oregon State University; 2003. [cited 2021 Apr 15].
Available from: http://hdl.handle.net/1957/31591.
Council of Science Editors:
Thirunavukarasu B. A study of solidification dynamics with liquid mass influx. [Masters Thesis]. Oregon State University; 2003. Available from: http://hdl.handle.net/1957/31591
Oregon State University
22.
Hawke, Shane R.
Effects of a thin, flexible nozzle on droplet formation and impingement.
Degree: MS, Mechanical Engineering, 2007, Oregon State University
URL: http://hdl.handle.net/1957/3817
► The droplet formation process in the vicinity of the nozzle exit and the behavior of a spreading droplet during impingement on a smooth glass surface…
(more)
▼ The droplet formation process in the vicinity of the nozzle exit and the behavior of a spreading droplet during impingement on a smooth glass surface were studied. Two nozzle geometries were tested. The first case was a stiff stainless steel nozzle plate 0.787 mm thick. The second case was a flexible stainless steel nozzle plate 0.102 mm thick. In each case, two different waveforms were used to drive the piezoelectric element in the droplet generator. This resulted in different meniscus behavior at the nozzle exit in each case. Leading and trailing edge velocities and the position of the leading edge relative to the nozzle were measured through use of double-frame images taken with a high-speed camera to describe the formation process at the nozzle. This data was displayed in both dimensional and non-dimensional form using capillary parameters. At the impingement surface, the high speed camera was used to record the spread rate and contact angle of the droplets. This research concluded that the flexible nozzle had a significant impact on droplet formation. Exit velocities were more than double those of the stiff nozzle, and break-off times were shorter for the flexible nozzle. One drawback of the flexible nozzle
was that satellite droplets were produced along with the main droplet, which did not happen with a stiff nozzle. Behavior at the impingement surface was also noted to be different in each case. However, this is not directly related to the different nozzles themselves, but rather the fact that the nozzles resulted in different droplet velocities. The spread rate of the droplets was observed to increase as the impingement velocity was increased. The dynamic contact angles were also measured and compared to existing models found in the literature. Although there were discrepancies, it is likely that these are due to the difference in Weber numbers between this experiment and the models.
Advisors/Committee Members: Liburdy, James A. (advisor), Narayanan, Vinod (committee member).
Subjects/Keywords: droplet formation; Spray nozzles
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APA (6th Edition):
Hawke, S. R. (2007). Effects of a thin, flexible nozzle on droplet formation and impingement. (Masters Thesis). Oregon State University. Retrieved from http://hdl.handle.net/1957/3817
Chicago Manual of Style (16th Edition):
Hawke, Shane R. “Effects of a thin, flexible nozzle on droplet formation and impingement.” 2007. Masters Thesis, Oregon State University. Accessed April 15, 2021.
http://hdl.handle.net/1957/3817.
MLA Handbook (7th Edition):
Hawke, Shane R. “Effects of a thin, flexible nozzle on droplet formation and impingement.” 2007. Web. 15 Apr 2021.
Vancouver:
Hawke SR. Effects of a thin, flexible nozzle on droplet formation and impingement. [Internet] [Masters thesis]. Oregon State University; 2007. [cited 2021 Apr 15].
Available from: http://hdl.handle.net/1957/3817.
Council of Science Editors:
Hawke SR. Effects of a thin, flexible nozzle on droplet formation and impingement. [Masters Thesis]. Oregon State University; 2007. Available from: http://hdl.handle.net/1957/3817
Oregon State University
23.
Tobias, Jason A.
Characterization of the near-field flow structure of an acoustically self-excited jet in a large enclosure using particle image velocimetry (PIV).
Degree: MS, Mechanical Engineering, 2007, Oregon State University
URL: http://hdl.handle.net/1957/5580
► An experimental study of the near-field flow structure produced by an incompressible turbulent Acoustically Self-Excited Jet (ASEJ) in a large enclosure using Particle Image Velocimetry…
(more)
▼ An experimental study of the near-field flow structure produced by an incompressible turbulent Acoustically Self-Excited Jet (ASEJ) in a large enclosure using Particle Image Velocimetry (PIV) is presented. The salient feature of this jet is that it provides an increase in near-field mixing and turbulence without additional external power input. In the present experiments, the jet exits into an enclosure whose nearest wall is 26 jet diameters from the nozzle center. Three nozzle exit Reynolds numbers (Re) of 27,000, 49,000 and 71,000 were studied for two frequencies of excitation of the jet, and compared with the free pipe jet without excitation. Results indicate that the peak turbulence intensity based on nozzle exit velocity in the nearfield is enhanced by as much as 50 percent for the ASEJ compared to the unexcited jet at downstream locations less than 2 nozzle diameters away from the nozzle exit. The second stage of excitation is found to increase the near-field turbulence to a greater extent than the first stage of excitation. Entrainment of surrounding air in the nearfield of the jet is enhanced due to the acoustic self-excitation. Streamwise variations of streamwise mean velocity along the centerline of the jet compare well with data reported by Hasan and Hussain (1982) for both the unexcited jet and first stage ASEJ. Peak turbulent intensity along the jet centerline is lower than that reported by Hasan and Hussain (1982) for first stage ASEJ but higher for second stage ASEJ. This
enhancement in turbulent intensity for second stage ASEJ is thought to be due to
acoustic feedback from the enclosure walls.
Advisors/Committee Members: Narayanan, Vinod (advisor), Liburdy, James A. (committee member).
Subjects/Keywords: axisymmetric turbulent jet; Jets – Fluid dynamics
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APA (6th Edition):
Tobias, J. A. (2007). Characterization of the near-field flow structure of an acoustically self-excited jet in a large enclosure using particle image velocimetry (PIV). (Masters Thesis). Oregon State University. Retrieved from http://hdl.handle.net/1957/5580
Chicago Manual of Style (16th Edition):
Tobias, Jason A. “Characterization of the near-field flow structure of an acoustically self-excited jet in a large enclosure using particle image velocimetry (PIV).” 2007. Masters Thesis, Oregon State University. Accessed April 15, 2021.
http://hdl.handle.net/1957/5580.
MLA Handbook (7th Edition):
Tobias, Jason A. “Characterization of the near-field flow structure of an acoustically self-excited jet in a large enclosure using particle image velocimetry (PIV).” 2007. Web. 15 Apr 2021.
Vancouver:
Tobias JA. Characterization of the near-field flow structure of an acoustically self-excited jet in a large enclosure using particle image velocimetry (PIV). [Internet] [Masters thesis]. Oregon State University; 2007. [cited 2021 Apr 15].
Available from: http://hdl.handle.net/1957/5580.
Council of Science Editors:
Tobias JA. Characterization of the near-field flow structure of an acoustically self-excited jet in a large enclosure using particle image velocimetry (PIV). [Masters Thesis]. Oregon State University; 2007. Available from: http://hdl.handle.net/1957/5580
. 
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