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2017-03-28
Technical Paper
2017-01-0210
Ahmed Imtiaz Uddin, Abd El-Rahman Ali Hekal, Dipan P. Arora, Alaa El-Sharkawy, Sadek S. Rahman
With the increase in demand of fuel efficient transportation system, various efforts have been made to collect waste energies to reduce the fuel consumption and emissions in the automobiles. Currently, in a typical internal combustion engine, approximately one third of the fossil fuel combustion by-product is wasted heat. By collecting the heat emitted through the exhaust systems using heat exchanger concept can be used to increase the passenger heating and comfort during cold ambient conditions as well as reduction of exhaust system surface temperatures. Lower exhaust surface temperature improves the durability of various under-hood and underbody components near the exhaust pipe. In this paper, the effects of integrating a gas/coolant heat exchanger close to the engine catalytic converter on reduction of the exhaust surface temperature for various real-world dynamic driving conditions are presented.
2017-03-28
Technical Paper
2017-01-0215
Mohammad Nahid, Amin Sharfuzzaman, Joydip Saha, Harry Chen, Sadek S. Rahman
More stringent Federal emission regulations and fuel economy requirements have driven the automotive industry toward more sophisticated vehicle thermal management systems to best utilize the waste heat and improve driveline efficiency. The final drive unit in light and heavy duty trucks usually consists of geared transmission and differential housed in a lubricated axle. The automotive rear axles is one of the major sources of power loss in the driveline due to gear friction, churning and bearing loss and have a significant effect on overall vehicle fuel economy. These losses vary significantly with the viscosity of the lubricant. Also the temperatures of the lubricant are critical to the overall axle performance in terms of power losses, fatigue life and wear.
2017-03-28
Technical Paper
2017-01-0213
Rezwanur Rahman, Sadek S. Rahman
The demand for Hybrid Electrified Vehicles (HEVs) is increasing due to government regulations on fuel economy. The battery systems in a PHEV have achieved tremendous efficiency over past few years. The system has become more delicate and complex in architecture which requires sophisticated thermal management. Primary reason behind this is to ensure effective cooling of the cells. Hence the current work has emphasized on developing a “Physics based” thermal management modeling framework for a typical battery system. In this work the thermal energy conservation has been analyzed thoroughly in order to develop necessary governing equations for the system. Since cooling is merely a complex process in HEV battery systems, the underlying mechanics has been investigated using the current model. The framework was kept generic so that it can be applied with various architectures. In this paper the process has been standardized in this context.
2017-03-28
Technical Paper
2017-01-0629
John Kuo, George Garfinkel
Detailed thermal modeling of liquid-cooled vehicle traction battery assemblies using Computational Fluid Dynamics (CFD) analysis techniques usually involves large models to accurately resolve small cooling channel details. For large battery packs, some of these meshes may exceed current computational capabilities or result in long and expensive computational efforts. Moreover, only steady-state thermal predictions are usually performed, as drive-cycle transient simulations become impractical due to the exceedingly long solving times. To tackle this problem, an innovative segregated method has been developed for thermal analysis of liquid-cooled traction batteries, where battery cells and their active cooling system are divided into three parts: the cell, the cold plate and the interface between them.
2017-03-28
Technical Paper
2017-01-0732
Stijn Broekaert, Thomas De Cuyper, Michel De Paepe, Sebastian Verhelst
In recent years, Homogeneous Charge Compression Ignition (HCCI) engines have received much interest, because they combine a high thermal efficiency with near-zero emissions of NOx and soot. However, the maximum attainable load is limited by the occurrence of ringing combustion. This happens when the combustion rate is too fast, leading to pressure oscillations in the combustion chamber accompanied by a knocking sound. Some researchers have hypothesized that these pressure oscillations increase the heat transfer from the combustion gases to the cylinder wall, due to the breakup of the thermal boundary layer. No experimental results are available to support this hypothesis, as no experimental studies have been conducted to investigate the heat transfer during ringing operation.
2017-03-28
Technical Paper
2017-01-0134
Jan Eller, Heinrich Reister, Thomas Binner, Nils Widdecke, Jochen Wiedemann
There is a growing need for life-cycle data – so-called collectives – when developing components like elastomer engine mounts. Current standardized extreme load cases are not sufficient for establishing such collectives. Instead of using endurance testing data – which necessitates full vehicle on-road tests – a prediction methodology for component temperature collectives utilizing existing 3D CFD simulation models is presented. The method uses support points to approximate the full collective. Each support point is defined by a component temperature and a position on the time axis of the collective. Since it is the only currently available source for component temperature data, endurance testing data is used to develop the new method. The component temperature range in this data set is divided in temperature bands. Groups of driving states are determined which are each representative of an individual band.
2017-03-28
Technical Paper
2017-01-0141
Ray Host, Peter Moilanen, Marcus Fried, Bhageerath Bogi
Future vehicle North American emissions standards (e.g., North American SULEV 30) require the exhaust catalyst to be >80% efficient by 20 seconds after the engine has been started in the Federal Test Procedure. Turbocharged engines are especially challenged to deliver fast catalyst lightoff since the presence of the turbocharger in the exhaust flow path significantly increases exhaust system heat losses. A solution to delivering cost effective SULEV30 emissions in turbocharged engines is to achieve fast catalyst light-off by reducing exhaust system heat losses in cold start, without increasing catalyst thermal degradation during high load operation. A CAE methodology to assess the thermal performance of exhaust system hardware options, from the exhaust port to the catalyst brick face is described, which assures compliance with future emissions regulations.
2017-03-28
Technical Paper
2017-01-0175
Jing He, Bill Johnston, Debasish Dhar, Loren Lohmeyer
The traditionally used refrigerant in mobile air conditioning (MAC), R134a, has a high GWP of 1,300 and is to be banned in EU market for new passenger cars and light commercial vehicles from January 1, 2017. In US, EPA has listed R134a as unacceptable for new light-duty vehicles beginning in Model Year 2021. The natural refrigerant, R744 (CO2), remains a viable solution to replace R134a due to its environmental friendliness, low cost, non-flammability, and high volumetric heat capacity. One challenge of R744 vapor compression system is reduced efficiency with ambient temperature. Prior research has demonstrated that a parallel or multistage compression cycle represents a superior design to a conventional single-compression cycle in that it not only improves the optimum cooling efficiency, but also brings down the optimum discharge pressure.
2017-03-28
Technical Paper
2017-01-1298
Kamlesh Yadav, Abhishek Sinha, Rajdeep Singh Khurana
Vehicle Hood being the face of a passenger car poses a challenge to meet the regulatory and aesthetic requirements. However, the urge to make a saleable product makes aesthetics a primary condition. This eventually makes the role of structure optimization much more important. A recent development in the Indian automotive industry, which is known for dynamics of cost competitive cars, has posed the challenge to make passenger cars meeting the regulation and having optimized cost. This work is application of structure optimization of Hood and design of peripheral parts for meeting pedestrian protection performance keeping the focus on having cost-effective solution. This paper discusses Headform compliance of the work done on one of the flagship model of Maruti Suzuki India Ltd., providing detailed analysis of the procedure followed from introduction stage of regulatory requirement in the project to final validation of the engineering intent.
2017-03-28
Technical Paper
2017-01-1300
Raj Jayachandran, Bhimaraddi Alavandi, Matt Niesluchowski, Erika Low, Yafang Miao, Yi Zhang
An engine cooling system in an automotive vehicle comprises of heat exchangers such as a radiator, charge air cooler, and oil coolers along with engine cooling fans. Typical automotive engine-cooling fan assembly includes an electric motor mounted on to a shroud that encloses radiator core. Typically a fan shroud is made of plastic material and holds one or two motors and is supported at four corners. One of the main drivers of a fan shroud design is Noise, Vibration, and Harshness requirements, without compromising the main function - airflow requirement for cooling. Usually, stiffness requirement is not given adequate attention in arriving at optimal design of a fan shroud. Research Council for Automotive Repairs (RCAR), based in Europe, issues vehicle ratings on the basis of its performance in Low Speed Damageability (LSD) tests. One such test is a 15kph, 40% offset rigid wall impact to the front of the vehicle.
2017-03-28
Technical Paper
2017-01-0251
Suneel Kumar Sharma, Ashish Kumar Sahu, Subhash Bhosale
Stringent emission norms by government and higher fuel economy targets have urged automotive companies to look beyond conventional methods of optimization to achieve optimal design with minimum mass, which also meets the desired level of performance targets at systems as well as at vehicle level. In conventional optimization method, experts from each domain work independently to improve the performance based on their own domain knowledge which may not lead to optimum design considering the performance parameters of all domains. It is time consuming and tedious as it is an iterative method. Also it fails to highlight the conflicting design solutions. With increase in computational power automotive companies are now adopting Multi-Disciplinary Optimization (MDO) approach which is capable to handle heterogeneous domains in parallel. It facilitates to understand the limitations of performances of all domains to achieve good balance between them.
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. Tight vehicle packaging caused by downsizing has further magnified this concern. In an automobile, fuel is stored in a metal or plastic container known as fuel tank. In addition to fuel storage, temperature inside fuel tank has to be maintained at a certain level to control high fuel evaporation rate and prevent deterioration of other systems part performance. In case of under-body fuel tank layout, fuel tank surface temperature is governed by engine, exhaust system layout and road loads. Mechanical shielding has been found to be an efficient defence to the heat management problem. However, what to shield, where to place the shield and the best shield material are major design challenges. This paper focuses on different approaches followed to reduce temperature on fuel tank surface by varying material, geometry & layout of heat insulators.
2017-03-28
Technical Paper
2017-01-1036
Silvia Marelli, Simone Gandolfi, Massimo Capobianco
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 thermo-mechanical 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 developed by the Authors is adopted for the correction of compressor steady flow maps.
2017-03-28
Technical Paper
2017-01-0172
Suhas Venkatappa, Manfred Koberstein, Zhengyu Liu
Due to regulations related to global warming, the auto industry is transitioning to the use of a new refrigerant R1234yf in many markets/regions. This transition to the new refrigerant was considered to be a minor development effort with main focus on improved sealing, improving cooling capacity with adding content such as Internal Heat Exchanger (IHX) to recoup the lower cooling efficiency of R1234yf compared to R134a. There were no redesigns of major refrigerant system components expected with the introduction of R1234yf. The actual implementation of this refrigerant has proven to be more challenging due to several NVH issues. Some of the challenges related to NVH are driven by the differences in refrigerant characteristics – mass flow rate, velocity of sound in refrigerant.
2017-03-28
Technical Paper
2017-01-0183
Mingyu Wang, Timothy Craig, Edward Wolfe, Tim J LaClair, Zhiming Gao, Michael Levin, Danrich Demitroff, Furqan Shaikh
Without the waste heat available from the engine of a conventional automobile, electric vehicles (EVs) must provide heat to the cabin for climate control using energy stored in the vehicle. In current EV designs, this energy is typically provided by electrical energy from the traction battery. In very cold climatic conditions, the driving range of an EV can be reduced by 50% or more. To minimize this EV range penalty, a novel thermal energy storage system has been designed to provide cabin heat in EVs and Plug-in Hybrid Electric Vehicles (PHEVs) using the stored latent heat from an advanced phase change material (PCM). This system is known as the Electrical PCM-based Thermal Heating System (ePATHS). When the EV is connected to the electric grid to charge its traction battery, the ePATHS system is also “charged” by melting the PCM. The stored thermal energy is subsequently deployed for cabin heating during driving.
2017-03-28
Technical Paper
2017-01-0171
Quansheng Zhang, Yan Meng, Christopher Greiner, Ciro Soto, William Schwartz, Mark Jennings
In this paper, the tradeoff relationship between the Air Conditioning (A/C) system performance and vehicle fuel economy for a hybrid electric vehicle during the SC03 drive cycle is presented. First, an A/C system model was integrated into Ford’s HEV simulation environment. Then, a system-level sensitivity study was performed on a stand-alone A/C system simulator, by formulating a static optimization problem which minimizes the total energy use of actuators, and maintains an identical cooling capacity. Afterwards, a vehicle-level sensitivity study was conducted with all controllers incorporated in sensitivity analysis software, under three types of formulations of cooling capacity constraints. Finally, the common observation from both studies, that the compressor speed dominates the cooling capacity and the EDF fan has a marginal influence, is explained using the thermodynamics of a vapor compression cycle.
2017-03-28
Technical Paper
2017-01-0125
Marco Pizzi, Mauro Zorzetto, Alberto Barbano, Piercarlo Merlano, Luca Vercellotti
The reduction of emissions in gasoline and diesel engines is driving the introduction of systems implementing additives in liquid form: in particular water for injection systems in gasoline engines and urea solutions (AD-blue) in SCR systems in diesel engines. Unfortunately water and AD-Blue can freeze in the car operative temperature range. In both cases the tanks must be equipped with heaters to guarantee a sufficient amount of additives in liquid form. Currently used technologies are ceramic PTC elements and distributed metal resistors. Ceramic PTC based heaters concentrate all the power in small volumes. They need thermally conductive elements distributing the power over a wide area. The assembly is complex and the cost of the metal parts and related packaging technologies used to insulate the heater from the environment (water or urea) is typically high. Metal resistors are cheaper but must be controlled in current.
2017-03-28
Technical Paper
2017-01-0163
Gursaran D. Mathur
In southern states (e.g., Arizona) typically people drive their vehicles in summer by running vehicle’s air conditioning systems in recirculation modes only. Carbon dioxide exhaled by occupants remains within the cabin during operation in recirculation mode. The concentration of carbon dioxide starts increasing in the cabin. The CO2 that is inhaled by the occupants goes into their blood stream that negatively affects occupant’s health. ASHRAE Standard 62 specifies the safe levels of carbon dioxide in conditioned space for humans. The CO2 concentration limit per ASHRAE is 700 ppm over the ambient conditions on a continuous basis. Current global average ambient concentration level of CO2 as of March 2015 (NOAA, 2016) is approximately 401 ppm. Hence, if the CO2 concentration exceeds approximately 1100 ppm inside of a home or a vehicle cabin, then we must introduce outside air into the home or vehicle cabin to reduce the CO2 concentration.
2017-03-28
Technical Paper
2017-01-0157
Forrest Jehlik, Simeon Iliev, Eric Wood, Jeff Gonder
It is widely understood that cold ambient temperatures negatively impact vehicle system efficiency. This is due to increased friction (engine oil, transmission, and driveline viscous effects), cold start enrichment, heat transfer, and air density variations. Although the science of quantifying steady-state vehicle component efficiency is mature, transient component efficiency over dynamic ambient real-world conditions is less understood and quantified. This work characterizes transmission efficiency utilizing transmission heating technologies over various drive cycles and ambient conditions. Dynamometer testing over hot and cold ambient temperatures was conducted for two vehicles utilizing transmission warming technologies, and one vehicle using pads to pre-heat the transmission. For the vehicles with transmission heating technologies, tests were conducted with the systems both on and off to compare gains in efficiency.
2017-03-28
Technical Paper
2017-01-1303
Nobuhisa Yasuda, Shinichi Nishizawa, Maiko Ikeda, Tadashi Sakai
The purpose of this study is to validate a reverse engineering based design method for automotive trunk lid torsion bars (TLTB) in order to determine a free shape that meets a target closed shape as well as a specified torque. A TLTB is a trunk lid component that uses torsional restoring force to facilitate the lifting open of a trunk lid, as well as to maintain the open position. Bend points and torque at a closed trunk position are specified by a car maker. Conventionally, a TLTB supplier determines bend points of the free shape by rotating the given bend points from a closed position around a certain axis to satisfy the specified torque at the closed position. Bend points of a deformed TLTB shape in the closed position often do not match the target bend points given by a car maker when designed by the conventional method, which can potentially cause interference issues with surrounding components.
2017-03-28
Technical Paper
2017-01-0169
Ward J. Atkinson, William Raymond Hill, Gursaran D. Mathur
The EPA has issued regulations in the Final Rulemaking for 2017-2025 Light-Duty Vehicle Greenhouse Gas Emission Standards and Corporate Average Fuel Economy Standards (420r12901-3). This document provides credits against the fuel economy regulations for various Air Conditioning technologies. One of these credits is associated with increased use of re-circulation air mode, when the Ambient is over 24°C (75°F.). The authors want to communicate the experiences in their careers that highlighted issues with air quality in the interior of the vehicle cabin. Cabin contamination sources may result in safety and health issues for both younger and older drivers. Alertness concerns may hinder their ability to operate a vehicle safely.
2017-03-28
Technical Paper
2017-01-0152
Gang Liu, Zheng Zhao, Hao Guan, Chunhui Zhang, Dingwei Gao, Yongwei Cao
Advanced technology of thermal management is an effective method to reduce fuel consumption. There are several different technologies for coolant control, for example, electric water pump, split cooling and coolant control module. Through 1D thermal management simulation, coolant control module was chose for the test due to the best benefit for fuel consumption under NEDC cycle. 1D thermal management simulation model includes vehicle, cooling system, lubrication system and detailed engine model with all friction components. Coolant control module is designed to fix on 2.0L turbocharger GDI gasoline and to control 5 coolant ways, including radiator, by-pass, engine oil cooler, cabin heater and transmission oil cooler. The function and strategy was verified on designed test-bed. The vehicle with coolant control module is test under NEDC cycle. The results show the coolant temperature rise time decrease and the benefit of fuel consumption reach 1.8%.
2017-03-28
Technical Paper
2017-01-0158
Masaaki Nakamura, Koichi Machida, Kiyohiro Shimokawa
A diesel engine is advantageous in its high thermal efficiency, however it still wastes more than 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. The experimental system was single loop type with its total length of 3160mm. A mixture of argon and helium was used as the working gas. Cordierite honeycombs of 100mm long with cell density of 1200 cpsi were used as the regenerators in both the heating and cooling parts. The heat exchanger, which was made of anoxic copper with high thermal conductivity, was maintained at room temperature by recirculating cooling water.
2017-03-28
Technical Paper
2017-01-1217
Jiangong Zhu, Zechang Sun, Xuezhe Wei, Haifeng Dai
An alternating current (AC) heating method for a NMC lithium-ion battery with 8Ah capacity is proposed in the paper. 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. 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 obtains the maximum temperature rise at 64A and 1Hz, which takes 1800s to heat up the battery from -25oC to 18oC.
2017-03-28
Technical Paper
2017-01-0192
Antti Lajunen
The presented research investigates the energy efficiency and performance of cabin thermal management in electric vehicles. Efficient cabin thermal management is important, because the energy used for cabin cooling and heating can drastically reduce the operating range of electric vehicles. A simulation model of a full electric vehicle with cabin heating and cooling systems was developed in AMESim software. The model includes an electric powertrain, thermal systems and a cabin model. The cabin heating, ventilation and air conditioning (HVAC) systems consist of a heat pump, electric heater and waste heat recovery system as well as necessary auxiliary devices. The waste heat is recovered from power electronics and electric motor cooling circuit by a specific heat exchanger which is integrated in the heat pump refrigerant circuit. In colder conditions, a separate electric heater can be used to ensure passenger comfort.
2017-03-28
Technical Paper
2017-01-1304
Alejandro Rosas Vazquez, Fernando Paisano, Diego Santillan Gutierrez
For many years the use of in-mold fasteners has been avoided for various reasons including: not fully understand the load cases in the part, the fear for quality issues to occur, the need for servicing, or the lack of understanding the complexity of all failure modes. The most common solution has been the use of secondary operations to provide attachments, such as, screws, metal clips, heat staking, sonic welding or other methods which are ultimately a waste in the process and increase manufacturing costs. The purpose of this paper is to take the reader through a design process which allows for the design of in-molded attachment clips on plastic parts. The paper explores the design process for in-molded attachment clips starting with a design concept idea, testing the basic concept using a personal 3D printer, optimizing the design with physical tests and CAE analysis, and finally producing high resolution 3D prototypes for validation and tuning.
2017-03-28
Technical Paper
2017-01-0216
Joydip Saha, Harshit Coutinho, Sadek S. Rahman
Current and future automotive systems are becoming more complex than ever. They consist of different subsystems such as the engine, transmission, cooling system, driveline, controls systems, HVAC and active/passive safety systems. Hardware and software development for each of these subsystems have different timeline’s. The subsystems are usually developed by different teams within an organization and in some cases are also developed by suppliers. These are some of the main hurdles for carrying out a system level analysis of the vehicle earlier in the development process. Model.CONNECT was used to overcome the above mentioned hurdles by connecting a driveline model, a cooling system model, thermal controller and two-phase flow models with minimal effort.
2017-03-28
Technical Paper
2017-01-1393
Georges Beurier, Michelle Cardoso, Xuguang Wang
A new experimental seat was designed to investigate sitting biomechanics. Previous literature suggested links between sitting discomfort and shear forces, however, research on this topic is limited. The evaluation of sitting discomfort derived from past research has been primarily associated with seat pressure distribution. The key innovative feature of the experimental seat is not only pressure distribution evaluation but shear forces as well. The seat pan of the experimental seat compromises of a matrix of 52 cylinders, each equipped with a tri-axial force sensor, enabling us to measure both normal and shear forces. The position of each cylinder is also adjustable permitting a uniform pressure distribution underneath the soft tissue of the buttocks and thighs. Backrest, armrests, seat pan and flooring are highly adjustable and equipped with forces sensors to measure contact forces.
2017-03-28
Technical Paper
2017-01-0142
Chunhui Zhang, Mesbah Uddin, Lee Foster
The demand for better fuel economy pushed by both the consumers and Environmental Protection Agency (EPA), made OEMs to put more effort on other areas beside vehicle external aerodynamics for. 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 underhood and underbody devices, and emission regulations. The challenge of the under-hood airflow management is not only due to the complexity of under-hood compartment, but also as a result of the influence of the heat sources, like the condenser, radiator, powertrain and exhaust system, on the airflow characteristics. The temperature change of the under-hood airflow undermines the accuracy of the pure aerodynamic analysis. In this study, 3D CFD simulation was used to investigate the under-hood aero-thermal flow features.
2017-03-28
Technical Paper
2017-01-0505
Aditi Chavannavar
Polyurethane dispersions (PUDs) have seen rapid growth in recent years as alternatives to their solvent based analogs. They offer the advantages of enabling low VOC formulations while providing superior appearance and mechanical properties. Polyurethane-acrylic hybrids combine the advantages of a polyurethane dispersion with the benefits of an acrylic emulsion. This synergistic combination offers properties such as good hardness development and chemical resistance in addition to enhanced mechanical properties. In this paper, we discuss new PUD-acrylic hybrids that are NMP and solvent free, have a pendulum hardness of 100 oscillations compared to a standard acrylic emulsion that has 80; and offer excellent scratch and abrasion resistance equivalent to that of an acrylic system. In addition to these, the new polyurethane dispersions provide good haptic qualities and have excellent adhesion to plastic substrates such as ABS, PC, PMMA and PVC.
Viewing 1 to 30 of 8575