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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
URL: http://hdl.handle.net/2152/68397 
► 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…
(more)
▼ 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 April 11, 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. 11 Apr 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 Apr 11].
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
University of Texas – Austin
2.
Ates, Murat, 1982-.
Fuel economy modeling of light-duty and heavy-duty vehicles, and coastdown study.
Degree: MSin Engineering, Mechanical Engineering, 2009, University of Texas – Austin
URL: http://hdl.handle.net/2152/ETD-UT-2009-05-80
► Development of a fuel economy model for light-duty and heavy-duty vehicles is part of the Texas Department of Transportation’s “Estimating Texas Motor Vehicle Operating Costs”…
(more)
▼ Development of a fuel economy model for light-duty and heavy-duty vehicles is
part of the Texas Department of Transportation’s “Estimating Texas Motor Vehicle
Operating Costs” project. A literature review for models that could be used to predict the
fuel economy of light-duty and heavy-duty vehicles resulted in selection of
coastdown
coefficients to simulate the combined effects of aerodynamic drag and tire rolling
resistance.
For light-duty vehicles, advantage can be taken of the modeling data provided by
the United States Environmental Protection Agency (EPA) for adjusting chassis
dynamometers to allow accurate determination of emissions and fuel economy so that
compliance with emissions standards and Corporate Average Fuel Economy (CAFE)
regulations can be assessed. Initially, EPA provided vehicle-specific data that were
relevant to a physics-based model of the forces at the tire-road interface. Due to some
limitations of these model parameters, EPA now provides three vehicle-specific
coefficients obtained from vehicle
coastdown data. These coefficients can be related
back to the original physics-based model of the forces at the tire-road interface, but not in
a manner that allows the original modeling parameters to be extracted from the
coastdown coefficients. Nevertheless, as long as the operation of a light-duty vehicle
does not involve extreme acceleration or deceleration transients, the coefficients available
from the EPA can be used to accurately predict fuel economy.
Manufacturers of heavy-duty vehicles are not required to meet any sort of CAFE
standards, and the engines used in heavy-duty vehicles, rather than the vehicles
themselves, are tested (using an engine dynamometer) to determine compliance with
emissions standards. Therefore, EPA provides no data that could be useful for predicting
the fuel economy of heavy-duty vehicles. Therefore, it is necessary to perform heavyduty
coastdown tests in order to predict fuel economy, and use these tests to develop
vehicle-specific coefficients for the force at the tire-road interface. Given these
coefficients, the fuel economy of a heavy-duty vehicle can be calculated for any driving
schedule. The heavy-duty vehicle model developed for this project is limited to pre-2007
calendar year heavy-duty vehicles due to the adverse effects of emissions components
that were necessary to comply with emissions standards that went into effect January
2007.
Advisors/Committee Members: Matthews, Ronald D. (advisor), Hall, Matthew J. (committee member).
Subjects/Keywords: Fuel Economy; Fuel Economy Modeling; Light-Duty; Heavy-Duty; Automotive; Vehicle; Coastdown; Coast-down; AVL ADVISOR; AVL CRUISE; AVL BOOST
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APA ·
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MLA ·
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CSE |
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APA (6th Edition):
Ates, Murat, 1. (2009). Fuel economy modeling of light-duty and heavy-duty vehicles, and coastdown study. (Masters Thesis). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/ETD-UT-2009-05-80
Chicago Manual of Style (16th Edition):
Ates, Murat, 1982-. “Fuel economy modeling of light-duty and heavy-duty vehicles, and coastdown study.” 2009. Masters Thesis, University of Texas – Austin. Accessed April 11, 2021.
http://hdl.handle.net/2152/ETD-UT-2009-05-80.
MLA Handbook (7th Edition):
Ates, Murat, 1982-. “Fuel economy modeling of light-duty and heavy-duty vehicles, and coastdown study.” 2009. Web. 11 Apr 2021.
Vancouver:
Ates, Murat 1. Fuel economy modeling of light-duty and heavy-duty vehicles, and coastdown study. [Internet] [Masters thesis]. University of Texas – Austin; 2009. [cited 2021 Apr 11].
Available from: http://hdl.handle.net/2152/ETD-UT-2009-05-80.
Council of Science Editors:
Ates, Murat 1. Fuel economy modeling of light-duty and heavy-duty vehicles, and coastdown study. [Masters Thesis]. University of Texas – Austin; 2009. Available from: http://hdl.handle.net/2152/ETD-UT-2009-05-80
3.
Hausmann, Austin Joseph.
Advances in Electric Drive Vehicle Modeling with Subsequent Experimentation and Analysis.
Degree: MS, Mechanical Engineering, 2012, University of Kansas
URL: http://hdl.handle.net/1808/10187
► A combination of stricter emissions regulatory standards and rising oil prices is leading many automotive manufacturers to explore alternative energy vehicles. In an effort to…
(more)
▼ A combination of stricter emissions regulatory standards and rising oil prices is leading many automotive manufacturers to explore alternative energy vehicles. In an effort to achieve zero tail pipe emissions, many of these manufacturers are investigating electric drive vehicle technology. In an effort to provide University of Kansas students and researchers with a stand-alone tool for predicting electric vehicle performance, this work covers the development and validation of various models and techniques. Chapter 2 investigates the practicality of vehicle coast down testing as a suitable replacement to moving floor wind tunnel experimentation. The recent implementation of full-scale moving floor wind tunnels is forcing a re-estimation of previous coefficient of drag determinations. Moreover, these wind tunnels are relatively expensive to build and operate and may not capture concepts such as linear and quadratic velocity dependency along with the influence of tire pressure on rolling resistance. The testing method explained here improves the accuracy of the fundamental vehicle modeling equations while remaining relatively affordable. The third chapter outlines various models used to predict battery capacity. The authors investigate the effectiveness of Peukert's Law and its application in lithium-based batteries. The work then presents the various effects of battery temperature on capacity and outlines previous work in the field. This paper then expands upon Peukert's equation in order to include both variable current and temperature effects. The method proposed captures these requirements based on a relative maximum capacity criterion. Experimental methods presented in the paper provide an economical testing procedure capable of producing the required coefficients in order to build a high-level, yet accurate state of charge prediction model. Moreover, this work utilizes automotive grade lithium-based batteries for realistic outcomes in the electrified vehicle realm. The fourth chapter describes an advanced numerical model for computing vehicle energy usage performance. This work demonstrates the physical and mathematical theories involved, while building on the principles of Newton's second law of motion. Moreover, this chapter covers the equipment, software, and processes necessary for collecting the required data. Furthermore, a real world, on-road driving cycle provides for a quantification of accuracy. Multiple University of Kansas student project vehicles are then studied using parametric studies applicable to the operating requirements of the vehicles. Further investigation demonstrates the accuracy and trends associated with the advanced models presented in Chapters 2 and 3. Lastly, chapter 5 investigates the design and building of a graphical user interface (GUI) for controlling the models created in the previous three chapters. The chapter continues to outline the creation of a stand-alone GUI as well as instructions for implementation, usage, and data analysis.
Advisors/Committee Members: Depcik, Christopher (advisor), Dougherty, Ronald L. (cmtemember), Faddis, Terry (cmtemember).
Subjects/Keywords: Automotive engineering; Mechanical engineering; Battery; Coastdown; Electric; Lithium; Modeling; Vehicle
…111
Table 2: VW coastdown study parameters determined using Chapter 2 derived model… …contains the findings associated with the
development of an advanced on-road coastdown method and… …velocity fitting
of coastdown data. Journal of Wind Engineering and Industrial Aerodynamics,
1991…
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APA ·
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APA (6th Edition):
Hausmann, A. J. (2012). Advances in Electric Drive Vehicle Modeling with Subsequent Experimentation and Analysis. (Masters Thesis). University of Kansas. Retrieved from http://hdl.handle.net/1808/10187
Chicago Manual of Style (16th Edition):
Hausmann, Austin Joseph. “Advances in Electric Drive Vehicle Modeling with Subsequent Experimentation and Analysis.” 2012. Masters Thesis, University of Kansas. Accessed April 11, 2021.
http://hdl.handle.net/1808/10187.
MLA Handbook (7th Edition):
Hausmann, Austin Joseph. “Advances in Electric Drive Vehicle Modeling with Subsequent Experimentation and Analysis.” 2012. Web. 11 Apr 2021.
Vancouver:
Hausmann AJ. Advances in Electric Drive Vehicle Modeling with Subsequent Experimentation and Analysis. [Internet] [Masters thesis]. University of Kansas; 2012. [cited 2021 Apr 11].
Available from: http://hdl.handle.net/1808/10187.
Council of Science Editors:
Hausmann AJ. Advances in Electric Drive Vehicle Modeling with Subsequent Experimentation and Analysis. [Masters Thesis]. University of Kansas; 2012. Available from: http://hdl.handle.net/1808/10187
4.
Lundberg, Petter.
Investigation of the transient nature of rolling resistance on an operating Heavy Duty Vehicle.
Degree: Physics, 2014, Umeå University
URL: http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-93298
► An operating vehicle requires energy to oppose the subjected driving resistances. This energy is supplied via the fuel combustion in the engine. Decreasing the…
(more)
▼ An operating vehicle requires energy to oppose the subjected driving resistances. This energy is supplied via the fuel combustion in the engine. Decreasing the opposing driving resistances for an operating vehicle increases its fuel efficiency: an effect which is highly valued in today’s industry, both from an environmental and economical point of view. Therefore a lot of progress has been made during recent years in the area of fuel efficient vehicles, even though some driving resistances still rises perplexity. These resistances are the air drag Fd generated by the viscous air opposing the vehicles propulsion and the rolling resistance Frr generated mainly by the hysteresis caused by the deformation cycle of the viscoelastic pneumatic tires. The energy losses associated with the air drag and rolling resistance account for the majority of the driving resistances facing an operating vehicle, and depends on numerous stochastic and ambient parameters, some of which are highly correlated both within and between the two resistances. To increase the understanding of the driving mechanics behind the energy losses associated with the complexity that is rolling resistance, a set of complete vehicle tests has been carried out. These tests were carried out on the test track Malmby Fairground, using a Scania CV AB developed R440 truck equipped with various sensors connected in one measurement system. Under certain conditions, these parameters can allow for an investigation of the rolling resistance, and a separation of the rolling resistance and air drag via explicit subtraction of the air drag from the measured traction force. This method is possible since the aerodynamic property AHDVCd(β) to some extent can be generated from wind tunnel tests and CFD simulations. Two measurement series that enable the above formulated method of separation were designed and carried out, using two separate measurement methods. One which enables the investigation of the transient nature of rolling resistance as it strives for stationarity, where the vehicle is operated under constant velocities i.e. no acceleration, and one using the well established method of coastdown, where no driving torque is applied. The drive cycles spanned a range of velocities, which allowed for dynamic and stationary analyses of both the tire temperature- and the velocity dependence of rolling resistance. When analysing the results of the transient analysis, a strong dependence upon tire temperature for given constant low velocity i.e. v ≤ 60 kmh−1 was clearly visible. The indicated dependency showed that the rolling resistance decreased as the tire temperature increased over time at a given velocity, and vice versa, towards a stationary temperature and thereby rolling resistance. The tire temperature evolution from one constant velocity to another, took place well within 50 min to a somewhat stationary value. However, even though the tire temperature had reached stationarity, rolling…
Subjects/Keywords: Rolling resistance; Air drag; Heavy Duty Vehicles; Vehicle dynamics; Complete vehicle test; Coastdown; Effective radius; ACEA; Pneumatic tires; Driving resistances; Energy efficiency; Rullmotstånd; Luftmotstånd; Tunga fordon; Fordonsdynamik; Helfordonstest; Utrullningstest; Effektiv radie; ACEA; Pneumatiska däck; Körmotstånd; Energieffektivitet.
…laps . . . .
D.3 Transient separation of driving resistances
D.4 Coastdown verification… …coastdown measurement series to verify
the potential possibility of energy loss separation and the… …equipage tires is the
so called coastdown method. By allowing the operating vehicle to coastdown… …requires the vehicle to coastdown, the
method only considers non-driven wheels under a…
Record Details
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Record Details
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❌
APA ·
Chicago ·
MLA ·
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CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Lundberg, P. (2014). Investigation of the transient nature of rolling resistance on an operating Heavy Duty Vehicle. (Thesis). Umeå University. Retrieved from http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-93298
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Lundberg, Petter. “Investigation of the transient nature of rolling resistance on an operating Heavy Duty Vehicle.” 2014. Thesis, Umeå University. Accessed April 11, 2021.
http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-93298.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Lundberg, Petter. “Investigation of the transient nature of rolling resistance on an operating Heavy Duty Vehicle.” 2014. Web. 11 Apr 2021.
Vancouver:
Lundberg P. Investigation of the transient nature of rolling resistance on an operating Heavy Duty Vehicle. [Internet] [Thesis]. Umeå University; 2014. [cited 2021 Apr 11].
Available from: http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-93298.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Lundberg P. Investigation of the transient nature of rolling resistance on an operating Heavy Duty Vehicle. [Thesis]. Umeå University; 2014. Available from: http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-93298
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
. 
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