+publisher:"Old Dominion University" +contributor:("A. Sidney Roberts, Jr.")

1. Rust, William W., III. Two-Dimensional Heat Loss From a Building Slab Including Convective Effects in Saturated Soil.

Degree: PhD, Mechanical & Aerospace Engineering, 1991, Old Dominion University

URL: https://digitalcommons.odu.edu/mae_etds/271

► The heat loss from a building slab was investigated. The continuity equation, Darcy's Law and the energy equation were formulated to include the temperature… (more)

▼ The heat loss from a building slab was investigated. The continuity equation, Darcy's Law and the energy equation were formulated to include the temperature dependence of viscosity and density of water. The governing equations and appropriate boundary conditions were transformed into dimensionless variables. A finite difference numerical scheme was constructed based on the Gauss-Seidel method by lines and solved iteratively in alternating directions. A correlation between the geometrical characteristics of the domain, the convective surface heating parameters, and the total nondimensional slab heat loss in two dimensions was discovered. Furthermore, the correlation was extended to three-dimensional slabs and produced good agreement with analyses by other workers using different methods. Numerical results were validated by comparison with a proprietary finite element solver in two dimensions. Moreover, a scaled laboratory simulation of building slab heat loss was conducted. The agreement between the numerically predicted heat loss and the experimental results was good for solid media. For porous media, the apparent thermal conductivity for both dry and saturated media was measured and found to be in consonance with data produced by others. The observed dye tracer positions in the flow visualization confirmed the predicted positions. The results of the experiments indicated that: the volume averaged method of computing apparent thermal conductivity of the porous media was inadequate and experimentally determined conductivity should be used; and, the time required for a particle to transit a fixed path in the porous media is independent of the thermal conductivity of the media. Finally, the numerical model was extended to include surface evaporation at the earth interface. Surface evaporation increased slab heat transfer by approximately ten percent compared to a non-evaporating surface condition. Advisors/Committee Members: A. Sidney Roberts, Jr., Surendra N. Tiwari, Robert L. Ash, John J. Swetits, Ronald N. Jensen.

Subjects/Keywords: Heat; Porous materials; Thermal properties; Building slab; Saturated soil; Mechanical Engineering

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APA (6^th Edition):

Rust, William W., I. (1991). Two-Dimensional Heat Loss From a Building Slab Including Convective Effects in Saturated Soil. (Doctoral Dissertation). Old Dominion University. Retrieved from https://digitalcommons.odu.edu/mae_etds/271

Chicago Manual of Style (16^th Edition):

Rust, William W., III. “Two-Dimensional Heat Loss From a Building Slab Including Convective Effects in Saturated Soil.” 1991. Doctoral Dissertation, Old Dominion University. Accessed March 02, 2021. https://digitalcommons.odu.edu/mae_etds/271.

MLA Handbook (7^th Edition):

Rust, William W., III. “Two-Dimensional Heat Loss From a Building Slab Including Convective Effects in Saturated Soil.” 1991. Web. 02 Mar 2021.

Vancouver:

Rust, William W. I. Two-Dimensional Heat Loss From a Building Slab Including Convective Effects in Saturated Soil. [Internet] [Doctoral dissertation]. Old Dominion University; 1991. [cited 2021 Mar 02]. Available from: https://digitalcommons.odu.edu/mae_etds/271.

Council of Science Editors:

Rust, William W. I. Two-Dimensional Heat Loss From a Building Slab Including Convective Effects in Saturated Soil. [Doctoral Dissertation]. Old Dominion University; 1991. Available from: https://digitalcommons.odu.edu/mae_etds/271

2. Augustsson, Tommy Reinhold Robert. Effects of Multiple Scattering and Surface Albedo on the Photochemistry of the Troposphere.

Degree: PhD, Mechanical & Aerospace Engineering, 1981, Old Dominion University

URL: https://digitalcommons.odu.edu/mae_etds/214

► A one-dimensional photochemical model of the troposphere containing the species of the nitrogen, oxygen, carbon, hydrogen, and sulfur families has been developed and used… (more)

▼ A one-dimensional photochemical model of the troposphere containing the species of the nitrogen, oxygen, carbon, hydrogen, and sulfur families has been developed and used to investigate the vertical profiles and the natural (including atmospheric chemical reactions) and anthropogenic sources and sinks of these species. The species continuity equations are solved numerically applying prescribed boundary conditions. The vertical flux is simulated by use of the parameterized eddy diffusion coefficients. Heterogeneous losses (e.g. rainout, gas-to-particle chemistry, and dry deposition), are parameterized to make calculated profiles consistent with measurements. The photochemical model is coupled to a radiative transfer model that calculates the radiation field due to the incoming solar radiation which initiates much of the photochemistry of the troposphere. Comparisons of vertical profiles of tropospheric species are made between the Leighton approximation, widely used in most tropospheric models, and the detailed radiative transfer matrix inversion model used in this study. The radiative transfer code includes the effects of multiple scattering due to molecules and aerosols, pure absorption and surface albedo on the transfer of incoming solar radiation. The results indicate that significant differences exist for several key photolysis frequencies and species number density profiles between the Leighton approximation and the profiles generated with the more detailed radiative transfer matrix inversion technique used in this study. Most species show enhanced vertical profiles when the more realistic treatment of the incoming solar radiation field is included. Furthermore, most species increase in concentration as a function of increasing surface albedo. A few species, notably ozone, exhibit decreased levels of concentration when the realistic radiative transfer model is used. The effect of the detailed treatment of incoming solar radiation on the photochemistry of the troposphere is discussed. Advisors/Committee Members: Surendra N. Tiwari, Joel S. levine, Robert Ash, A. Sidney Roberts, Jr., Billy T. Upchurch.

Subjects/Keywords: Albedo; Scattering; Troposphere; Photochemical model; Mechanical Engineering

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APA (6^th Edition):

Augustsson, T. R. R. (1981). Effects of Multiple Scattering and Surface Albedo on the Photochemistry of the Troposphere. (Doctoral Dissertation). Old Dominion University. Retrieved from https://digitalcommons.odu.edu/mae_etds/214

Chicago Manual of Style (16^th Edition):

Augustsson, Tommy Reinhold Robert. “Effects of Multiple Scattering and Surface Albedo on the Photochemistry of the Troposphere.” 1981. Doctoral Dissertation, Old Dominion University. Accessed March 02, 2021. https://digitalcommons.odu.edu/mae_etds/214.

MLA Handbook (7^th Edition):

Augustsson, Tommy Reinhold Robert. “Effects of Multiple Scattering and Surface Albedo on the Photochemistry of the Troposphere.” 1981. Web. 02 Mar 2021.

Vancouver:

Augustsson TRR. Effects of Multiple Scattering and Surface Albedo on the Photochemistry of the Troposphere. [Internet] [Doctoral dissertation]. Old Dominion University; 1981. [cited 2021 Mar 02]. Available from: https://digitalcommons.odu.edu/mae_etds/214.

Council of Science Editors:

Augustsson TRR. Effects of Multiple Scattering and Surface Albedo on the Photochemistry of the Troposphere. [Doctoral Dissertation]. Old Dominion University; 1981. Available from: https://digitalcommons.odu.edu/mae_etds/214

3. Gartenberg, Ehud. Low Speed Flowfield Characterization by Infrared Measurements of Surface Temperatures.

Degree: PhD, Mechanical & Aerospace Engineering, 1989, Old Dominion University

URL: https://digitalcommons.odu.edu/mae_etds/233

► An experimental program was aimed at identifying areas in low speed aerodynamic research where infrared imaging systems can make significant contributions. Implementing a new… (more)

Subjects/Keywords: Surface temperatures; Low speed aerodynamic research; Mechanical Engineering; Structures and Materials

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APA (6^th Edition):

Gartenberg, E. (1989). Low Speed Flowfield Characterization by Infrared Measurements of Surface Temperatures. (Doctoral Dissertation). Old Dominion University. Retrieved from https://digitalcommons.odu.edu/mae_etds/233

Chicago Manual of Style (16^th Edition):

Gartenberg, Ehud. “Low Speed Flowfield Characterization by Infrared Measurements of Surface Temperatures.” 1989. Doctoral Dissertation, Old Dominion University. Accessed March 02, 2021. https://digitalcommons.odu.edu/mae_etds/233.

MLA Handbook (7^th Edition):

Gartenberg, Ehud. “Low Speed Flowfield Characterization by Infrared Measurements of Surface Temperatures.” 1989. Web. 02 Mar 2021.

Vancouver:

Gartenberg E. Low Speed Flowfield Characterization by Infrared Measurements of Surface Temperatures. [Internet] [Doctoral dissertation]. Old Dominion University; 1989. [cited 2021 Mar 02]. Available from: https://digitalcommons.odu.edu/mae_etds/233.

Council of Science Editors:

Gartenberg E. Low Speed Flowfield Characterization by Infrared Measurements of Surface Temperatures. [Doctoral Dissertation]. Old Dominion University; 1989. Available from: https://digitalcommons.odu.edu/mae_etds/233

4. Alfahaid, Ahmed F. Effects of Ventilation on Human Thermal Comfort in Rooms.

Degree: PhD, Mechanical Engineering, 2000, Old Dominion University

URL: 9780599965423 ; https://digitalcommons.odu.edu/mae_etds/99

► Nowadays, the majority of people spend up to 90% of their time indoors; as a result, the maintenance of optimal indoor climate conditions has… (more)

Subjects/Keywords: Indoor climate; Thermal comfort; Ventilation; Mechanical Engineering

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APA (6^th Edition):

Alfahaid, A. F. (2000). Effects of Ventilation on Human Thermal Comfort in Rooms. (Doctoral Dissertation). Old Dominion University. Retrieved from 9780599965423 ; https://digitalcommons.odu.edu/mae_etds/99

Chicago Manual of Style (16^th Edition):

Alfahaid, Ahmed F. “Effects of Ventilation on Human Thermal Comfort in Rooms.” 2000. Doctoral Dissertation, Old Dominion University. Accessed March 02, 2021. 9780599965423 ; https://digitalcommons.odu.edu/mae_etds/99.

MLA Handbook (7^th Edition):

Alfahaid, Ahmed F. “Effects of Ventilation on Human Thermal Comfort in Rooms.” 2000. Web. 02 Mar 2021.

Vancouver:

Alfahaid AF. Effects of Ventilation on Human Thermal Comfort in Rooms. [Internet] [Doctoral dissertation]. Old Dominion University; 2000. [cited 2021 Mar 02]. Available from: 9780599965423 ; https://digitalcommons.odu.edu/mae_etds/99.

Council of Science Editors:

Alfahaid AF. Effects of Ventilation on Human Thermal Comfort in Rooms. [Doctoral Dissertation]. Old Dominion University; 2000. Available from: 9780599965423 ; https://digitalcommons.odu.edu/mae_etds/99

5. Bayraktar, Tuba. Investigation of Port Fuel Injector Spray Mass Distribution by Laser Induced Fluorescence.

Degree: PhD, Mechanical Engineering, 2002, Old Dominion University

URL: 9780493883106 ; https://digitalcommons.odu.edu/mae_etds/111

► Modern internal combustion engines have stringent requirements for performance and reduced toxic emissions. The fuel delivery system, and particularly the fuel injectors, have a… (more)

▼ Modern internal combustion engines have stringent requirements for performance and reduced toxic emissions. The fuel delivery system, and particularly the fuel injectors, have a vital role in reducing unburned hydrocarbons (HC) and carbon monoxide (CO) in exhaust emission. The main goal of this study is to map the spatial and temporal distribution of the spray from a low-pressure gasoline fuel injector. To attain this goal, three tasks were performed: (1) the experimental investigation of the spray oscillation as functions of operating pressure and injector timing, (2) the determination of the appropriate dye/fuel combinations for one particular experimental technique, and (3) the demonstration of the capabilities of a Computational Fluid Dynamics (CFD) code, Fluent, in the dispersed two-phase flow solutions. An experimental technique, planar laser induced fluorescence (PLIF), was employed to investigate the spatial and temporal distribution of the spray mass from a set of four-hole, split-stream port fuel injectors. The spatial and temporal spray evolution in a horizontal cross-section was imaged instantaneously via detection of fluorescence intensities. The lateral displacement of the spray mass is clearly displayed in time sequence via the PLIF images, and the spray instability is shown to be sensitively dependent upon small geometric differences along the internal flow paths. In the course of a study to develop a quantitative PLIF diagnostic for the mass distribution emanating from a liquid fuel injector, spectroscopic results were assembled for certain dye/fuel solutions. Experiments were performed with combinations of hydrocarbon solvents and organic dyes. Results are presented in the form of absorption and emission spectra, including extinction coefficients with error analysis, comparisons with data in the literature, and Stokes shift estimates. A Computational Fluid Dynamics (CFD) code, Fluent, was employed to demonstrate its capabilities in the solution of dispersed two-phase flows. The dispersed two-phase flow consists of discrete elements surrounded by a continuous phase. The continuous phase equations were solved in an Eulerian reference frame. The Lagrangian approach was used to track packets of discrete phase elements. Inputs of the numerical dispersed two-phase flow model were obtained from the conditions of the PLIF experiments. Two cases were solved with the same input and boundary conditions. In the first case the spray consists of droplets with 100 μm diameter. A linear droplet diameter distribution between 40 and 100 μm was specified in the second case. Results indicate the existence of a core region with higher velocity values for both cases. The core region appears at the spray center close to the injection tip. The increase in the spray temperature towards the outlet boundary is larger for the constant droplet diameter case than the linear droplet diameter distribution case. Negligible evaporation is observed in the solution domain for both cases. Advisors/Committee Members: A. Sidney Roberts, Jr., Surendra N. Tiwari, Arthur C. Taylor, III, Amin N. Dharamsi.

Subjects/Keywords: Fuel injector; Fuel sprays; Mass distribution; Spray; Mechanical Engineering

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Bayraktar, T. (2002). Investigation of Port Fuel Injector Spray Mass Distribution by Laser Induced Fluorescence. (Doctoral Dissertation). Old Dominion University. Retrieved from 9780493883106 ; https://digitalcommons.odu.edu/mae_etds/111

Chicago Manual of Style (16^th Edition):

Bayraktar, Tuba. “Investigation of Port Fuel Injector Spray Mass Distribution by Laser Induced Fluorescence.” 2002. Doctoral Dissertation, Old Dominion University. Accessed March 02, 2021. 9780493883106 ; https://digitalcommons.odu.edu/mae_etds/111.

MLA Handbook (7^th Edition):

Bayraktar, Tuba. “Investigation of Port Fuel Injector Spray Mass Distribution by Laser Induced Fluorescence.” 2002. Web. 02 Mar 2021.

Vancouver:

Bayraktar T. Investigation of Port Fuel Injector Spray Mass Distribution by Laser Induced Fluorescence. [Internet] [Doctoral dissertation]. Old Dominion University; 2002. [cited 2021 Mar 02]. Available from: 9780493883106 ; https://digitalcommons.odu.edu/mae_etds/111.

Council of Science Editors:

Bayraktar T. Investigation of Port Fuel Injector Spray Mass Distribution by Laser Induced Fluorescence. [Doctoral Dissertation]. Old Dominion University; 2002. Available from: 9780493883106 ; https://digitalcommons.odu.edu/mae_etds/111

6. Haimovitch, Yaacov. Investigation of Wall Injectors for Supersonic Mixing Enhancement.

Degree: PhD, Mechanical Engineering, 1994, Old Dominion University

URL: https://digitalcommons.odu.edu/mae_etds/135

► A comparative study of the interaction between wall mounted swept-ramp injectors and injector nozzle shape has been conducted in a constant area duct to… (more)

▼ A comparative study of the interaction between wall mounted swept-ramp injectors and injector nozzle shape has been conducted in a constant area duct to explore techniques to enhance mixing in scramjet combustors. The scramjet combustors are currently being developed for propulsion systems applications on the envisioned hypersonic vehicles. Short combustor residence time, a requirement for fuel injection parallel to the main flow in the combustor, and an overall strong sensitivity of the vehicle performance to the propulsion system motivated the investigation. The swept-ramp injector investigated in this study produces vortex shedding and local separation downstream of the injector's nozzle exit, at the ramp's base. Six different injector nozzle inserts for preconditioning the fuel flow were tested to explore the interaction between the preconditioned fuel jet and the vortical flowfield produced by the ramp. The six injector nozzle inserts were: circular nozzle (baseline), nozzle with three downstream facing steps in the divergent section, nozzle with four vortex generators, elliptical nozzle, tapered-slot nozzle, and trapezoidal nozzle, all having equal exit and throat areas. The main flow was air at Mach 2, and the fuel was simulated by air injected at Mach 1.63 and by helium injected at Mach 1.7. The main portion of the research involved a series of experiments conducted at the NASA Langley Research Center in the Mach 2 Traverse Jet Facility. Extensive flow field surveys, combined with Mie and Rayleigh scattering visualization were used to investigate the flow field. An existing three-dimensional Navier-Stokes code was used to conduct a numerical study which closely tracked the experimental effort. The injector performance was evaluated in terms of both the experimental and computational results. The different nozzle inserts showed only minor performance differences, indicating that the injectant/air mixing in the far-field is independent of the injector geometry, molecular weight of the injectant, and the initial convective Mach number. However, the nozzle with vortex generators displayed the highest mixing performance, and there is evidence that the tapered-slot nozzle has a promising mixing performance. In the vicinity of the ramp base, the flow is dominated by the strong vortical flow field generated by the swept-ramp while well downstream of the base ramp the quasi-axisymmetric flow pattern indicates a "loss of memory" of the near-field stirring, the flow being controlled by small-scale turbulence. The flow field characteristics (mixing and losses) of this mixing scheme are determined by the ramp, the injector inner geometry having a very little effect. The injectant penetration into the main flow at an average angle that is equal to the initial injection angle, suggests that the penetration can be controlled by changing the injection angle. Advisors/Committee Members: A. Sidney Roberts, Jr., E. Gartenberg, G. B. Northam, S. Tiwari, O. Baysal.

Subjects/Keywords: Wall injectors; Supersonic mixing; Scramjet combustors; Aerospace Engineering; Mechanical Engineering; Structures and Materials

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APA (6^th Edition):

Haimovitch, Y. (1994). Investigation of Wall Injectors for Supersonic Mixing Enhancement. (Doctoral Dissertation). Old Dominion University. Retrieved from https://digitalcommons.odu.edu/mae_etds/135

Chicago Manual of Style (16^th Edition):

Haimovitch, Yaacov. “Investigation of Wall Injectors for Supersonic Mixing Enhancement.” 1994. Doctoral Dissertation, Old Dominion University. Accessed March 02, 2021. https://digitalcommons.odu.edu/mae_etds/135.

MLA Handbook (7^th Edition):

Haimovitch, Yaacov. “Investigation of Wall Injectors for Supersonic Mixing Enhancement.” 1994. Web. 02 Mar 2021.

Vancouver:

Haimovitch Y. Investigation of Wall Injectors for Supersonic Mixing Enhancement. [Internet] [Doctoral dissertation]. Old Dominion University; 1994. [cited 2021 Mar 02]. Available from: https://digitalcommons.odu.edu/mae_etds/135.

Council of Science Editors:

Haimovitch Y. Investigation of Wall Injectors for Supersonic Mixing Enhancement. [Doctoral Dissertation]. Old Dominion University; 1994. Available from: https://digitalcommons.odu.edu/mae_etds/135

7. Larsen, Jack Cutler. Inversion and Analysis of Remotely Sensed Atmospheric Water Vapor Measurements at 940nm.

Degree: PhD, Mechanical Engineering, 1998, Old Dominion University

URL: 9780591815825 ; https://digitalcommons.odu.edu/mae_etds/145

► The understanding and acceptance of remotely sensed atmospheric data depends strongly on the steps taken to characterize experiment error and validate observations through comparisons… (more)

▼ The understanding and acceptance of remotely sensed atmospheric data depends strongly on the steps taken to characterize experiment error and validate observations through comparisons to other independent measurements. A formal error analysis of the Stratospheric Aerosol and Gas Experiment II (SAGE II) water vapor operational inversion algorithm is performed and compared to previous results. Random measurement errors were characterized by segmented least-squares profile fitting of the slant path absorption which found the error to be uncorrelated in the stratosphere with estimated variances significantly smaller than expected from 18-30 km. Estimates of null space error were developed from radiosonde hygrometers in the troposphere and from SAGE II in the stratosphere. Systematic model bias errors are significant only in the troposphere where they reach 20% at the surface. Systematic errors associated with radiative transfer modeling are similar to previous analyses. A comparative error budget study between the operational inversion algorithm and several other algorithms was conducted with formal error analysis and by examining the error characteristics of two years' data inverted with each algorithm. Four other algorithms were considered; onion peel, Mill-Drayson, Mill-Drayson with stratospheric profile smoothing, and a sparse grid non-linear least-squares fitting method. Stratospheric random errors were largest for the onion peel due to the lack of stratospheric profile smoothing while the Mill-Drayson with smoothing was identical to the operational. The Mill-Drayson algorithm exhibited random error reduction greater than expected from the form of the contribution function with stratospheric random errors approaching operational levels. The sparse grid contribution function was found to be relatively insensitive to grid point density and computationally intensive. SAGE II upper tropospheric observations are compared to radiosonde climatologies and in situ radiosonde reports. SAGE II clear sky climatologies are shown to be half the level of the clear/cloudy sky radiosonde climatologies while correlative comparisons display nearly the same amount of bias. Much of the bias is attributed to the least sensitive hygrometers with SAGE II agreeing quite well with the most accurate and responsive hygrometer. Incorporating isentropic trajectories into the pair matching process greatly increases the number of correlative points but does not materially affect the comparisons. Advisors/Committee Members: Surendra N. Tiwari, Robert L. Ash, William P. Chu, Gary E. Copeland, A. Sidney Roberts, Jr..

Subjects/Keywords: Atmospheric data; Water vapor; Measurements; Aerosols; Atmospheric Sciences; Mechanical Engineering; Remote Sensing

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APA (6^th Edition):

Larsen, J. C. (1998). Inversion and Analysis of Remotely Sensed Atmospheric Water Vapor Measurements at 940nm. (Doctoral Dissertation). Old Dominion University. Retrieved from 9780591815825 ; https://digitalcommons.odu.edu/mae_etds/145

Chicago Manual of Style (16^th Edition):

Larsen, Jack Cutler. “Inversion and Analysis of Remotely Sensed Atmospheric Water Vapor Measurements at 940nm.” 1998. Doctoral Dissertation, Old Dominion University. Accessed March 02, 2021. 9780591815825 ; https://digitalcommons.odu.edu/mae_etds/145.

MLA Handbook (7^th Edition):

Larsen, Jack Cutler. “Inversion and Analysis of Remotely Sensed Atmospheric Water Vapor Measurements at 940nm.” 1998. Web. 02 Mar 2021.

Vancouver:

Larsen JC. Inversion and Analysis of Remotely Sensed Atmospheric Water Vapor Measurements at 940nm. [Internet] [Doctoral dissertation]. Old Dominion University; 1998. [cited 2021 Mar 02]. Available from: 9780591815825 ; https://digitalcommons.odu.edu/mae_etds/145.

Council of Science Editors:

Larsen JC. Inversion and Analysis of Remotely Sensed Atmospheric Water Vapor Measurements at 940nm. [Doctoral Dissertation]. Old Dominion University; 1998. Available from: 9780591815825 ; https://digitalcommons.odu.edu/mae_etds/145

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