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Viewing 1 to 30 of 1322
2017-03-28
Technical Paper
2017-01-0214
Simon O. Omekanda, Rezwanur Rahman, Eric M. Lott, Sadek S. Rahman, Daniel E. Hornback
Designing an efficient transient thermal system model has become a very important task in improving fuel economy. As opposed to steady-state thermal models, part of the difficulty in designing a transient model is optimizing a set of inputs. The first objective in this work is to develop an engine compatible physics-based 1D thermal model for fuel economy and robust control. In order to capture and study the intrinsic thermo-physical nature, both generic “Three Mass” and “Eight Mass” engine model are developed. The models have been correlated heuristically using Simulink and Flowmaster, respectively. In order to extend the lumped mass engine model it also has been extended to Simulink model. In contrast to the complexity of the models the “Heuristic search” of input parameters has been found to be challenging and time consuming.
2017-03-28
Technical Paper
2017-01-1207
Satyam Panchal, Scott Mathewson, Roydon Fraser, Richard Culham, Michael Fowler
Abstract Lithium-ion batteries, which are nowadays common in laptops, cell phones, toys, and other portable electronic devices, are also viewed as a most promising advanced technology for electric and hybrid electric vehicles (EVs and HEVs), but battery manufacturers and automakers must understand the performance of these batteries when they are scaled up to the large sizes needed for the propulsion of the vehicle. In addition, accurate thermo-physical property input is crucial to thermal modeling. Therefore, a designer must study the thermal characteristics of batteries for improvement in the design of a thermal management system and also for thermal modeling. This work presents a purely experimental thermal characterization in terms of measurement of the temperature gradient and temperature response of a lithium-ion battery utilizing a promising electrode material, LiFePO4, in a prismatic pouch configuration.
2017-03-28
Technical Paper
2017-01-1217
Jiangong Zhu, Zechang Sun, Xuezhe Wei, Haifeng Dai
Abstract An alternating current (AC) heating method for a NMC lithium-ion battery with 8Ah capacity is proposed. The effects of excitation frequency, current amplitudes, and voltage limit condition on the temperature evolution are investigated experimentally. Current amplitudes are set to 24A(3C), 40(5C), and 64A(8C), and excitation frequencies are set to 300Hz, 100Hz, 30Hz, 10Hz, 5Hz, and 1Hz respectively. The voltage limitations are necessary to protect cells from overcharge and over-discharge. Therefore the voltage limit condition (4.2V/2.75V, 4.3V/2.65V, and 4.4V/2.55V) are also considered in depth to verify the feasibility of the AC heating method. The temperature rises prominently as the current increases, and the decrement of frequencies also lead to the obvious growth of battery temperature. The battery obtain the maximum temperature rise at 64A and 1Hz, which takes 1800s to heat up the battery from -25°C to 18°C.
2017-03-28
Technical Paper
2017-01-0627
Bo Yang, Peter Woyciesjes, Aleksei Gershun
Abstract In this paper, new test results in the use of electrochemical techniques to measure corrosion in extended life engine coolants are presented. Corrosion protection performance of the engine coolants (including both fresh coolants and simulated used coolants) for typical cooling system metals under heat rejecting and heat accepting surface corrosion conditions for both general corrosion and localized corrosion are measured under conditions similar to the ones encountered in vehicle engine cooling systems as a function of immersion time. Fleet tests of the coolants were also conducted. They are used to provide support on the electrochemical test methodologies adopted. The effective use of electrochemical techniques to aid the development of the next generation of extended life coolant technologies with improved corrosion protection performance and a longer service life will be demonstrated and discussed.
2017-03-28
Technical Paper
2017-01-0629
John Kuo, George Garfinkel
Abstract Thermal modeling of liquid-cooled vehicle traction battery assemblies using Computational Fluid Dynamics (CFD) usually involves large models to accurately resolve small cooling channel details, and intensive computation to simulate drive-cycle transient solutions. This paper proposes a segregated method to divide the system into three parts: the cells, the cold plate and the interface between them. Each of the three parts can be separated and thermally characterized and then combined to predict the overall system thermal behavior for both steady-state and transient operating conditions. The method largely simplifies battery thermal analysis to overcome the limitations of using large 3D CFD models especially for pack level dynamic drive cycle simulations.
2017-03-28
Technical Paper
2017-01-0633
Kurt Stuart, Terry Yan, James Mathias
Abstract In this paper, the air-standard cycle analysis is performed for a 5-stroke engine to obtain the indicated thermal efficiency and power output over a range of operating points and design characteristics, including engine RPM, compression ratio, overall expansion ratio, expansion cylinder clearance volume, and transfer port volume. The results are compared with those of a baseline 4-stroke engine. This analysis is accomplished by an air-standard thermodynamic model for both engines with heat release function with heat transfer and mass loss for both the combustion cylinder and the expansion cylinder. The results indicate increased thermal efficiency and power output over the baseline 4-stroke engine, depending on the engine RPM and overall expansion ratios.
2017-03-28
Technical Paper
2017-01-0513
Jose Serrano, Luis Miguel García-Cuevas lng, Andres Tiseira, Tatiana Rodriguez Usaquen, Guillaume Mijotte
Abstract The growing concerns about emissions in internal combustion engines, makes necessary a good prediction of the after-treatment inlet temperature in fast one-dimensional engine simulation codes. Different simple models have been developed during the last years which improve the prediction of the turbocharger heat transfer phenomena. Although these models produce good results when computing the turbine outlet temperature, those models focus on the axial heat transfer paths and lack the capability of producing detailed results about the internal thermal behavior of the turbocharger. In this work, a new version of heat transfer model for automotive turbochargers is presented. This model discretizes the turbocharger in both the radial and axial directions, and computes the heat transfer and temperature at different parts of the machine.
2017-03-28
Technical Paper
2017-01-0124
V N Bhasker, Abhinav Agarwal, Abhishek Sharma, Avisek Das, Nirajkumar Mishra
Abstract Vehicle heat management has become a serious concern due to escalating under-hood and exhaust temperatures. Compact vehicle packaging caused by downsizing has further magnified this concern. In an automobile, fuel is stored in a metallic or plastic fuel tank. In addition to fuel storage, temperature inside fuel tank has to be maintained at a certain limit in order to control high fuel evaporation rate and prevent deterioration of parts. The fuel tank surface temperature is governed by heat rejection from the engine, exhaust system and heat radiated from the road. Generally, mechanical shielding has been found to be an efficient defense to the heat management problem. However ‘what to shield’, ‘where to place the shield’ and ‘how to shield’ are the major challenges. This paper describes a methodology followed to reduce temperature on fuel tank surface by varying material, geometry and layout of heat shields.
2017-03-28
Technical Paper
2017-01-0127
Norimitsu Matsudaira, Mitsuru Iwasaki, Junichiro Hara, Tomohiko Furuhata, Tatsuya Arai, Yasuo Moriyoshi, Naohiro Hasegawa
Abstract Among the emerging technologies in order to meet ever stringent emission and fuel consumption regulations, Exhaust Gas Recirculation (EGR) system is becoming one of the prerequisites particularly for diesel engines. Although EGR cooler is considered to be an effective measure for further performance enhancement, exhaust gas soot deposition may cause degradation of the cooling. To address this issue, the authors studied the visualization of the soot deposition and removal phenomena to understand its behavior. Based on thermophoresis theory, which indicates that the effect of thermophoresis depends on the temperature difference between the gas and the wall surface exposed to the gas, a visualization method using a heated glass window was developed. By using glass with the transparent conductive oxide: tin-doped indium oxide, temperature of the heated glass surface is raised.
2017-03-28
Technical Paper
2017-01-0154
Sudhi Uppuluri, Hemant R Khalane, Ajay Naiknaware
Abstract With the upcoming regulations for fuel economy and emissions, there is a significant interest among vehicle OEMs and fleet managers in developing computational methodologies to help understand the influence and interactions of various key parameters on Fuel Economy and carbon dioxide emissions. The analysis of the vehicle as a complete system enables designers to understand the local and global effects of various technologies that can be employed for fuel economy and emission improvement. In addition, there is a particular interest in not only quantifying the benefit over standard duty-cycles but also for real world driving conditions. The present study investigates impact of exhaust heat recovery system (EHRS) on a typical 1.2L naturally aspirated gasoline engine passenger car representative of the India market.
2017-03-28
Technical Paper
2017-01-0150
Ankit Kumar Shukla, Raj Dhami, Aashish Bhargava, Sanjay Tiwari
Abstract In the current landscape of commercial vehicle industry, fuel economy is one of the major parameter for fleet owner’s profitability as well as greenhouse gasses emission. Less fuel efficiency results in more fuel consumption; use of conventional fuel in engines also makes environment polluted. The rapid growth in fuel prices has led to the demand for technologies that can improve the fuel efficiency of the vehicle. Phase change material (PCMs) for Thermal energy storage system (TES) is one of the specific technologies that not only can conserve energy to a large extent but also can reduce emission as well as the dependency on convention fuel. There is a great variety of PCMs that can be used for the extensive range of temperatures, making them attractive in a number of applications in automobiles.
2017-03-28
Technical Paper
2017-01-0158
Masaaki Nakamura, Koichi Machida, Kiyohiro Shimokawa
Abstract A diesel engine is advantageous in its high thermal efficiency, however it still wastes about 50% of total input energy to exhaust and cooling losses. A feasibility study of thermoacoustic refrigerator was carried out as one of the means to recuperate waste heat. The thermoacoustic refrigerator prototyped for this study showed a capability to achieve cooling temperature lower than -20 degree C, which indicated that the system has a potential to be used in refrigerator trucks not only for cargo compartment cooling but also for cabin cooling.
2017-03-28
Technical Paper
2017-01-0142
Chunhui Zhang, Mesbah Uddin, Lee Foster
Abstract The demand for better fuel economy pushed by both consumer and Environmental Protection Agency (EPA), made OEMs to put more effort on other areas beside vehicle external aerodynamics. As one of these areas, under-hood aero-thermal management has taken an important role in the new road vehicle design process, due to the combination of growing engine power demands, utilization of sophisticated under-hood and underbody devices, and emission regulations. The challenge of the under-hood aerothermal management is not only due to the complexity of under-hood compartment, but also as a result of the complex heat transfer phenomena involving conduction, convention and thermal radiation. In this study, 3D CFD simulations were used to investigate the under-hood aerothermal flow features. The full vehicle model with detailed under-hood components used in this study is a Hyundai Veloster. A commercial CDF code Star-CCM+ version 11.04 from CD-adapco was used to run all the simulations.
2017-03-28
Technical Paper
2017-01-0144
Zhijia Yang, Song Lan, Richard Stobart, Edward Winward, Rui Chen, Iain Harber
Abstract The application of state-of-art thermoelectric generator (TEG) in automotive engine has potential to reduce more than 2% fuel consumption and hence the CO2 emissions. This figure is expected to be increased to 5%~10% in the near future when new thermoelectric material with higher properties is fabricated. However, in order to maximize the TEG output power, there are a few issues need to be considered in the design stage such as the number of modules, the connection of modules, the geometry of the thermoelectric module, the DC-DC converter circuit, the geometry of the heat exchanger especially the hot side heat exchanger etc. These issues can only be investigated via a proper TEG model. The authors introduced four ways of TEG modelling which in the increasing complexity order are MATLB function based model, MATLAB Simscape based Simulink model, GT-power TEG model and CFD STAR-CCM+ model. Both Simscape model and GT-Power model have intrinsic dynamic model performance.
2017-03-28
Technical Paper
2017-01-0162
Jun Li, Lili Feng, Pega Hrnjak
Abstract This paper presents the results of an experimental study to determine the effect of vapor-liquid refrigerant separation in a microchannel condenser of a MAC system. R134a is used as the working fluid. A condenser with separation and a baseline condenser identical on the air side have been tested to evaluate the difference in the performance due to separation. Two categories of experiments have been conducted: the heat exchanger-level test and the system-level test. In the heat exchanger-level test it is found that the separation condenser condenses from 1.6% to 7.4% more mass flow than the baseline at the same inlet and outlet temperature (enthalpy); the separation condenser condenses the same mass flow to a lower temperature than the baseline condenser does. In the system-level test, COP is compared under the same superheat, subcooling and refrigerating capacity. Separation condenser shows up to 6.6% a higher COP than the baseline condenser.
2017-03-28
Technical Paper
2017-01-0159
Peng Liu, Ge-Qun Shu, Hua Tian, Xuan Wang, Dongzhan Jing
Abstract The environmental issues combined with the rising of crude oil price have attracted more interest in waste heat recovery of marine engine. Currently, the thermal efficiency of marine diesels only reaches 48~51%, and the rest energy is rejected to the environment. Meanwhile, energy is required when generating electricity and cooling that are necessary for vessels. Hence, the cogeneration system is treated as the promising technology to conform the strict environment regulation while offering a high energy utilization ratio. In this paper, an electricity and cooling cogeneration system combined of Organic Rankine Cycle (ORC) and Absorption Refrigeration Cycle (ARC) is proposed to recover waste heat from marine engine. ORC is applied to recover exhaust waste heat to provide electricity while ARC is used to utilize condensation heat of ORC to produce additional cooling.
2017-03-28
Technical Paper
2017-01-0190
Neelakandan Kandasamy, Steve Whelan
Abstract The range of Plug-In Electric Vehicles (EVs) is highly influenced by the electric power consumed by various sub systems, the major part of the power being used for vehicle climate control strategies in order to ensure an acceptable level of thermal comfort for the passengers. Driving range decreases with low temperatures in particular because cabin heating system requires significant amount of electric power. Range also decreases with high ambient temperatures because of the air conditioning system with electrically-driven compressor. Both thermal systems reduce EV driving range under real life operating cycles, which can be a barrier against market penetration. The structure of a vehicle is capable of absorbing a significant amount of heat when exposed to hot climate conditions. 50-70% of this heat penetrates through the glazing and raises both the internal cabin air temperature and the interior trim surface temperature.
2017-03-28
Technical Paper
2017-01-0184
Miyoko Oiwake, Ozeki Yoshiichi, Sogo Obata, Hideaki Nagano, Itsuhei Kohri
Abstract In order to develop various parts and components for hybrid electric vehicles, understanding the effect of their structure and thermal performance on their fuel consumption and cruising distance is essential. However, this essential information is generally not available to suppliers of vehicle parts and components. In this report, following a previous study of electric vehicles, a simple method is proposed as the first step to estimate the algorithm of the energy transmission and then the cruising performance for hybrid electric vehicles. The proposed method estimates the cruising performance using only the published information given to suppliers, who, in general, are not supplied with more detailed information. Further, an actual case study demonstrating application of the proposed method is also discussed.
2017-03-28
Technical Paper
2017-01-0620
Chandrakant Parmar, Sethuramalingam Tyagarajan, Sashikant Tiwari, Ravindra Thonge, S Arun Paul
Abstract The engine compartment of passenger car application contains various source which radiates the produced heat and raises the temperature level of the compartment. The rise in compartment temperature increases the body temperature of individual component. The rise in body temperature of critical components can endanger the durability or functionality of the specific component or a system in which it operates. The aim of this paper is to strategize thermal protection of the rear mounted engine and its components of a vehicle having radiator and cooling fan mounted in front. An additional ventilation fan with speed sensor is fitted alongside rear mounted engine and a unique monitoring technique framed in the EMS ECU to protect critical components like HT cables, alternators, ECUs, wiring harness etc. from thermal damage. The EMS continuously monitors the engine speed, vehicle speed and the PWM signal of ventilation fan to ensure the intended operation of the ventilation fan.
2017-03-28
Technical Paper
2017-01-0527
Arya Yazdani, Jeffrey Naber, Mahdi Shahbakhti, Paul Dice, Chris Glugla, Stephen Cooper, Douglas McEwan, Garlan Huberts
An accurate estimation of cycle-by-cycle in-cylinder mass and the composition of the cylinder charge is required for spark-ignition engine transient control strategies to obtain required torque, Air-Fuel-Ratio (AFR) and meet engine pollution regulations. Mass Air Flow (MAF) and Manifold Absolute Pressure (MAP) sensors have been utilized in different control strategies to achieve these targets; however, these sensors have response delay in transients. As an alternative to air flow metering, in-cylinder pressure sensors can be utilized to directly measure cylinder pressure, based on which, the amount of air charge can be estimated without the requirement to model the dynamics of the manifold.
2017-03-28
Technical Paper
2017-01-0526
Oldrich Vitek, Jan Macek
Abstract The proposed paper deals with thermodynamic optimization of highly flexible ICE (variable compression ratio, intake/exhaust VVA) while comparing e-turbocharging concept with classical one. The e-turbocharging approach is based on idea that compressor/turbine has its own electric machine (motor/generator) and that additional electric energy can be supplied/attached from/to engine crank train. Hence it allows independent control of compressor/turbine. On the other hand, classical approach is based on a standard mechanical connection between turbine and compressor. The whole system (flexible engine + boost device) is optimized under steady operation – low load (BMEP of 4 bar), medium load (BMEP of 13 bar), high load (BMEP of 30, 25 and 18 bar) and maximum load are considered. Moreover, 3 combustion concepts are considered – classical SI and CI, and ideal RCCI.
2017-03-28
Technical Paper
2017-01-0521
Richard Merrett, John Murray, Doug Kolak
Abstract The development of experimental ORC systems is an extremely complex, time consuming and costly task. Running a range of experiments on a number of different component configurations may be prohibitively expensive and subject to equipment issues and failures. Yet ORC systems offer significant potential for automotive manufacturers to improve vehicle efficiency, reduce fuel consumption and vehicle emissions; the technology is particularly relevant for those involved in the design and/or manufacture of heavy duty trucks. This paper is focused on the validation of a computational ORC system simulation tool against a number of SAE published test results based on the European Stationary Cycle. Such studies on industry standard systems are essential in order to help promote confidence in a virtual prototype approach.
2017-03-28
Technical Paper
2017-01-0732
Stijn Broekaert, Thomas De Cuyper, Michel De Paepe, Sebastian Verhelst
Abstract Homogeneous Charge Compression Ignition (HCCI) engines can achieve both a high thermal efficiency and near-zero emissions of NOx and soot. However, their maximum attainable load is limited by the occurrence of a ringing combustion. At high loads, the fast combustion rate gives rise to pressure oscillations in the combustion chamber accompanied by a ringing or knocking sound. In this work, it is investigated how these pressure oscillations affect the in-cylinder heat transfer and what the best approach is to model the heat transfer during ringing combustion. The heat transfer is measured with a thermopile heat flux sensor inside a CFR engine converted to HCCI operation. A variation of the mass fuel rate at different compression ratios is performed to measure the heat transfer during three different operating conditions: no, light and severe ringing. The occurrence of ringing increases both the peak heat flux and the total heat loss.
2017-03-28
Technical Paper
2017-01-0730
Jose M Desantes, J. Javier Lopez, Jose M Garcia-Oliver, Dario Lopez-Pintor
Abstract In this work, a 5-zone model has been applied to replicate the in-cylinder conditions evolution of a Rapid Compression-Expansion Machine (RCEM) in order to improve the chemical kinetic analyses by obtaining more accurate simulation results. To do so, CFD simulations under motoring conditions have been performed in order to identify the proper number of zones and their relative volume, walls surface and temperature. Furthermore, experiments have been carried out in an RCEM with different Primary Reference Fuels (PRF) blends under homogeneous conditions to obtain a database of ignition delays and in-cylinder pressure and temperature evolution profiles. Such experiments have been replicated in CHEMKIN by imposing the heat losses and volume profiles of the experimental facility using a 0-D 1-zone model. Then, the 5-zone model has been analogously solved and both results have been compared to the experimental ones.
2017-03-28
Technical Paper
2017-01-1036
Silvia Marelli, Simone Gandolfi, Massimo Capobianco
Abstract In the last few years, the effect of diabatic test conditions on compressor performance maps has been widely investigated leading some Authors to propose different correction models. The aim of the paper is to investigate the effect of heat transfer phenomena on the experimental definition of turbocharger maps, focusing on turbine performance. An experimental investigation on a small turbocharger for automotive application has been carried out and presented. The study focused onto the effects of internal heat transfer on turbine thermomechanical efficiency. The experimental campaign was developed considering the effect of different heat transfer state by varying turbine inlet temperature, oil and coolant temperature and compressor inlet pressure. An original model previously developed by the Authors is adopted for the correction of compressor steady flow maps.
2017-03-28
Technical Paper
2017-01-0157
Forrest Jehlik, Simeon Iliev, Eric Wood, Jeff Gonder
Abstract This work details two approaches for evaluating transmission warming technology: experimental dynamometer testing and development of a simplified transmission efficiency model to quantify effects under varied real world ambient and driving conditions. Two vehicles were used for this investigation: a 2013 Ford Taurus and a highly instrumented 2011 Ford Fusion (Taurus and Fusion). The Taurus included a production transmission warming system and was tested over hot and cold ambient temperatures with the transmission warming system enabled and disabled. A robot driver was used to minimize driver variability and increase repeatability. Additionally the instrumented Fusion was tested cold and with the transmission pre-heated prior to completing the test cycles. These data were used to develop a simplified thermally responsive transmission model to estimate effects of transmission warming in real world conditions.
2017-03-28
Technical Paper
2017-01-0192
Antti Lajunen
Abstract The energy used for cabin cooling and heating can drastically reduce the operating range of electric vehicles. The energy efficiency and performance of the cabin heating, ventilation and air conditioning (HVAC) system depend on the system configuration and ambient conditions. The presented research investigates the energy efficiency and performance of cabin thermal management in electric vehicles. A simulation model of cabin heating and cooling systems was developed in the AMESim software. Simulations were carried out in the standard test cycles and one real-world driving cycle to take into account different driving behaviors and environments. The cabin thermal management performance was analyzed in relation to ambient temperature, system efficiency and cabin thermal balance. The simulation results showed that the driving range can shorten more than 50% in extreme cold conditions.
2017-03-28
Technical Paper
2017-01-0191
Gene Titov, Jason Aaron Lustbader
Abstract The National Renewable Energy Laboratory’s (NREL’s) CoolSim MATLAB/Simulink modeling framework was used to explore control strategies for an electric vehicle combined loop system. Three system variants of increased complexity and efficiency were explored: a glycol-based positive temperature coefficient heater (PTC), PTC with power electronics and electric motor (PEEM) waste heat recovery, and PTC with PEEM waste heat recovery plus heat pump versions. Additionally, the benefit of electric motor preheating was considered. A two-level control strategy was developed where the mode selection and component control were treated separately. Only the parameters typically available by vehicle sensors were used to control the system. The control approach included a mode selection algorithm and controllers for the compressor speed, cabin blower flow rate, coolant flow rate, and the front-end heat exchanger coolant bypass rate.
2017-03-28
Technical Paper
2017-01-0631
David C. Ogbuaku, Timothy Potter, James M. Boileau
Abstract The need to increase the fuel-efficiency of modern vehicles while lowering the emission footprint is a continuous driver in automotive design. This has given rise to the use of engines with smaller displacements and higher power outputs. Compared to past engine designs, this combination generates greater amounts of excess heat which must be removed to ensure the durability of the engine. This has resulted in an increase in the number and size of the heat exchangers required to adequately cool the engine. Further, the use of smaller, more aerodynamic front-end designs has reduced the area available in the engine compartment to mount the heat exchangers. This is an issue, since the reduced engine compartment space is increasingly incapable of supporting an enlarged rectangular radiator system.
2017-03-28
Technical Paper
2017-01-0624
Jiaxin Liu, Sicheng Qin, Yankun Jiang, Shumo He
Abstract In this work, a XD132 Road Roller from XCMG in China was employed as a research basis to study the heat exchange performance of the heat dissipation module under varied working conditions. The module in the XD132 consists of a cooling fan and three radiators. At first, the numerical investigation on the elementary units of radiators was performed to obtain Colburn j factor and Fanning friction f factor, which were used for the ε-NTU method to predict the radiator performance. The fan was numerically tested in a wind test tunnel to acquire the performance curve. The performance data from both investigations were transformed into the boundary conditions of the numerical vehicle model in a virtual tunnel. A field experiment was carried out to validate the simulation accuracy, and an entrance coefficient was proposed to discuss the performance regularity under four working conditions.
Viewing 1 to 30 of 1322

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