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You searched for +publisher:"University of Texas – Austin" +contributor:("Roberts, Charles E."). Showing records 1 – 2 of 2 total matches.

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University of Texas – Austin

1. -1322-3556. Fuel economy predictions for heavy‐duty vehicles and quasi‐dimensional DI diesel engine numerical modeling.

Degree: PhD, Mechanical Engineering, 2018, University of Texas – Austin

A research team developed the University of Texas Fuel Economy Model to estimate the fuel consumption of both light-duty and heavy-duty vehicles operated on Texas roads. One of the objectives of the model was to be as flexible as possible in order to be capable of simulating a variety of vehicles, payloads, and traffic conditions. For heavy-duty vehicles, there are no prescribed driving cycles, there are no coastdown coefficients available from the EPA, and we relied on experimental brake specific fuel consumption maps for a few heavy-duty diesel engines. Heavy-duty vehicle drive cycles highly depend upon the vehicle load, the grade of the road, the engine size, and the traffic conditions. In order to capture real driving conditions 54 drive cycles with three different Class 8 trucks, three weight configurations, three traffic congestion levels, and two drivers are collected. Drive cycles obtained in this research include road grade and vehicle speed data with time. Due to the lack of data from EPA for calculating the road load force for heavy-duty vehicles, coastdown tests were performed. To generate generic fuel maps for the fuel economy model, a direct injection quasi-dimensional diesel engine model was developed based on in-cylinder images available in the literature. Sandia National Laboratory researchers obtained various images describing diesel spray evolution, spray mixing, premixed combustion, mixing controlled combustion, soot formation, and NOx formation via imaging technologies. Dec combined all of the available images to develop a conceptual diesel combustion model to describe diesel combustion from the start of injection up to the quasi-steady form of the jet. The end of injection behavior was left undescribed in this conceptual model because no clear image was available due to the chaotic behavior of diesel combustion. A conceptual end-of-injection diesel combustion behavior model was proposed to capture diesel combustion in its life span. A full-cycle quasi-dimensional direct injection diesel engine model was developed that represents the physical models, utilizing the conceptual model developed from imaging experiments and available experiment-based spray models, of the in-cylinder processes. The compression, expansion, and gas exchange stages are modeled via zero-dimensional single zone calculations. A full cycle simulation is necessary in order to capture the initial conditions of the closed section of the cycle and predict the brake specific fuel consumption accurately. Advisors/Committee Members: Matthews, Ronald D. (advisor), Hall, Matthew John (advisor), Ellzey, Janet L. (committee member), Ezekoye, Ofodike A. (committee member), Biros, George (committee member), Roberts, Charles E. (committee member).

Subjects/Keywords: Quasi-dimensional; Diesel; Engine; Heavy-duty; Direct injection; Numerical; Modeling; Combustion; Coastdown; Drive cycle; Fuel economy; Mathematical; Vehicle; Simulation; Class 8

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APA (6th Edition):

-1322-3556. (2018). Fuel economy predictions for heavy‐duty vehicles and quasi‐dimensional DI diesel engine numerical modeling. (Doctoral Dissertation). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/68397

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete

Chicago Manual of Style (16th Edition):

-1322-3556. “Fuel economy predictions for heavy‐duty vehicles and quasi‐dimensional DI diesel engine numerical modeling.” 2018. Doctoral Dissertation, University of Texas – Austin. Accessed March 05, 2021. http://hdl.handle.net/2152/68397.

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete

MLA Handbook (7th Edition):

-1322-3556. “Fuel economy predictions for heavy‐duty vehicles and quasi‐dimensional DI diesel engine numerical modeling.” 2018. Web. 05 Mar 2021.

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete

Vancouver:

-1322-3556. Fuel economy predictions for heavy‐duty vehicles and quasi‐dimensional DI diesel engine numerical modeling. [Internet] [Doctoral dissertation]. University of Texas – Austin; 2018. [cited 2021 Mar 05]. Available from: http://hdl.handle.net/2152/68397.

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete

Council of Science Editors:

-1322-3556. Fuel economy predictions for heavy‐duty vehicles and quasi‐dimensional DI diesel engine numerical modeling. [Doctoral Dissertation]. University of Texas – Austin; 2018. Available from: http://hdl.handle.net/2152/68397

Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete

2. Byun, Jung Joo. Laminar burning velocities and laminar flame speeds of multi-component fuel blends at elevated temperatures and pressures.

Degree: PhD, Mechanical Engineering, 2011, University of Texas – Austin

Iso-octane, n-heptane, ethanol and their blends were tested in a constant volume combustion chamber to measure laminar burning velocities. The experimental apparatus was modified from the previous version to an automatically-controlled system. Accuracy and speed of data acquisition were improved by this modification. The laminar burning velocity analysis code was also improved for minimized error and fast calculation. A large database of laminar burning velocities at elevated temperatures and pressures was established using this improved experimental apparatus and analysis code. From this large database of laminar burning velocities, laminar flame speeds were extracted. Laminar flame speeds of iso-octane, n-heptane and blends were investigated and analysed to derive new correlations to predict laminar flame speeds of any blending ratio. Ethanol and ethanol blends with iso-octane and/or n-heptane were also examined to see the role of ethanol in the blends. Generally, the results for iso-octane and n-heptane agree with published data. Additionally, blends of iso-octane and n-heptane exhibited flame speeds that followed linear blending relationships. A new flame speed model was successfully applied to these fuels. Ethanol and ethanol blends with iso-octane and/or n-heptane exhibited a strongly non-linear blending relationship and the new flame speed model was not applied to these fuels. It was shown that the addition of ethanol into iso-octane and/or n-heptane accelerated the flame speeds. Advisors/Committee Members: Hall, M. J. (Matthew John) (advisor), Matthews, Ronald D. (advisor), Ellzey, Janet L. (committee member), Ezekoye, Ofodike A. (committee member), Roberts, Charles E. (committee member).

Subjects/Keywords: Laminar flame speed; Laminar burning velocity; Fuel blends; Iso-octane; n-heptane; Ethanol

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

APA (6th Edition):

Byun, J. J. (2011). Laminar burning velocities and laminar flame speeds of multi-component fuel blends at elevated temperatures and pressures. (Doctoral Dissertation). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/ETD-UT-2011-05-516

Chicago Manual of Style (16th Edition):

Byun, Jung Joo. “Laminar burning velocities and laminar flame speeds of multi-component fuel blends at elevated temperatures and pressures.” 2011. Doctoral Dissertation, University of Texas – Austin. Accessed March 05, 2021. http://hdl.handle.net/2152/ETD-UT-2011-05-516.

MLA Handbook (7th Edition):

Byun, Jung Joo. “Laminar burning velocities and laminar flame speeds of multi-component fuel blends at elevated temperatures and pressures.” 2011. Web. 05 Mar 2021.

Vancouver:

Byun JJ. Laminar burning velocities and laminar flame speeds of multi-component fuel blends at elevated temperatures and pressures. [Internet] [Doctoral dissertation]. University of Texas – Austin; 2011. [cited 2021 Mar 05]. Available from: http://hdl.handle.net/2152/ETD-UT-2011-05-516.

Council of Science Editors:

Byun JJ. Laminar burning velocities and laminar flame speeds of multi-component fuel blends at elevated temperatures and pressures. [Doctoral Dissertation]. University of Texas – Austin; 2011. Available from: http://hdl.handle.net/2152/ETD-UT-2011-05-516

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