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Viewing 91 to 120 of 8585
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 an optimal design with minimum mass, which also meets the desired level of performance targets at the system as well as at vehicle level. In conventional optimization method, experts from each domain work independently to improve the performance based on their domain knowledge which may not lead to optimum design considering the performance parameters of all domain. It is time consuming and tedious process as it is an iterative method. Also, it fails to highlight the conflicting design solutions. With an increase in computational power, automotive companies are now adopting Multi-Disciplinary Optimization (MDO) approach which is capable of handling 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
2017-01-0141
Ray Host, Peter Moilanen, Marcus Fried, Bhageerath Bogi
Abstract Future vehicle North American emissions standards (e.g., North American Tier 3 Bin 30 or LEVIII SULEV 30) require the exhaust catalyst to be greater than 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 light-off since the presence of the turbocharger in the exhaust flow path significantly increases exhaust system heat losses. A solution to delivering cost effective SULEV 30 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 enables compliance with future emissions regulations.
2017-03-28
Technical Paper
2017-01-0152
Gang Liu, Zheng Zhao, Hao Guan, Chunhui Zhang, Dingwei Gao, Yongwei Cao
Abstract 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 prototype is designed and made. The function and strategy is verified on designed test-bed. The vehicle with coolant control module is running under NEDC cycle.
2017-03-28
Technical Paper
2017-01-0328
Yunkai Gao, Genhai Wang, Jingpeng Han
Abstract The multi-body dynamics simulation and physical iteration were carried out based on the 4-channel road simulation bench, the solution of fatigue test bench which was suitable for cab with frame and suspension was designed. Large load and displacement above the suspension can be loaded on the test bench, and the same weak position of cab exposed on the road test can be assessed well on the fatigue test bench. The effectiveness of the bench test solution was verified though comparative study. And it has important reference for the same type of cab assembly with suspension in the fatigue bench test. According to the durability specifications of cab assembly, a multi-body dynamics model with a satisfactory accuracy was built. And the fixture check and virtual iteration analysis were used to verify the effectiveness of the solution. According to the road load signal analysis and multi-body dynamics analysis results, the test bench with linear guide and spherical joint was built.
2017-03-28
Journal Article
2017-01-1213
Yilin Yin, Zhong Zheng, Song-Yul Choe
Abstract Analysis of thermal behavior of Lithium ion battery is one of crucial issues to ensure a safe and durable operation. Temperature is the physical quantity that is widely used for analysis, but limited for accurate investigations of behavior of heat generation of battery because of sensitivities affected by heat transfer in experiments. Calorimeter available commercially is widely used to measure the heat generation of battery, but does not follow required dynamics because of a relatively large thermal time constant given by cavity and a limited heat transfer capability. In this paper, we proposed a highly dynamic calorimeter that was constructed using two thermoelectric devices (TEMs). For the design of the calorimeter and its calibration, a printed circuit board (PCB) with the same size as the battery was used as a dummy load to generate controlled heat.
2017-03-28
Journal Article
2017-01-1215
Peter Haussmann, Joachim Melbert
Abstract Battery safety is the most critical requirement for the energy storage systems in hybrid and electric vehicles. The allowable battery temperature is limited with respect to the battery chemistry in order to avoid the risk of thermal runaway. Battery temperature monitoring is already implemented in electric vehicles, however only cell surface temperature can be measured at reasonable cost using conventional sensors. The internal cell temperature may exceed the surface temperature significantly at high current due to the finite internal electrical and thermal cell resistance. In this work, a novel approach for internal cell temperature measurement is proposed applying on board impedance spectroscopy. The method considers the temperature coefficient of the complex internal cell impedance. It can be observed by current and voltage measurements as usually performed by standard battery management systems.
2017-03-28
Technical Paper
2017-01-0515
Thomas De Cuyper, Stijn Broekaert, Duc-Khanh Nguyen, Kam Chana, Michel De Paepe, Sebastian Verhelst
Abstract Engine optimization requires a good understanding of the in-cylinder heat transfer since it affects the power output, engine efficiency and emissions of the engine. However little is known about the convective heat transfer inside the combustion chamber due to its complexity. To aid the understanding of the heat transfer phenomena in a Spark Ignition (SI) engine, accurate measurements of the local instantaneous heat flux are wanted. An improved understanding will lead to better heat transfer modelling, which will improve the accuracy of current simulation software. In this research, prototype thin film gauge (TFG) heat flux sensors are used to capture the transient in-cylinder heat flux within a Cooperative Fuel Research (CFR) engine. A two-zone temperature model is linked with the heat flux data. This allows the distinction between the convection coefficient in the unburned and burned zone.
2017-03-28
Technical Paper
2017-01-1678
Joseph Antony John Selvaraj, Sivapalan Balanayagam
Modern Instrument Panel Clusters (IPC) are equipped with thin film transistor (TFT) based displays. Contrary to conventional IPCs with hard gauges and liquid crystal diode (LCD) displays, TFT displays offer versatile usage of display area with soft gauges, reconfigurable menus, tell tales, graphics and warning messages etc., At the same time, the number of possible screen combinations, multicolor images validation and different screen arbitration become significantly complex. Thereby display validation turns out to be a complex and time consuming task in IPC validation. The task becomes even more complex when change requests are to be incorporated during final phases of development stage. This paper provides a novel solution that helps to validate any graphical and behavioral changes with minimum effort and maximum accuracy.
2017-03-28
Journal Article
2017-01-0126
Joshua W. Finn, John R. Wagner
Abstract Hybrid vehicle embedded systems and payloads require progressively more accurate and versatile thermal control mechanisms and strategies capable of withstanding harsh environments and increasing power density. The division of the cargo and passenger compartments into convective thermal zones which are independently managed can lead to a manageable temperature control problem. This study investigates the performance of a Peltier-effect thermoelectric zone cooling system to regulate the temperature of target objects (e.g., electronic controllers, auxiliary computer equipment, etc) within ground vehicles. Multiple thermoelectric cooling modules (TEC) are integrated with convective cooling fans to provide chilled air for convective heat transfer from a robust, compact, and solid state device. A series of control strategies have been designed and evaluated to track a prescribed time-varying temperature profile while minimizing power consumption.
2017-03-28
Journal Article
2017-01-0495
Michael Christian Haverkamp
Abstract The vehicle interior constitutes the multi-sensory environment of driver and passengers. Beside overall design and execution, materials and its surfaces are of specific interest to the customer. They are not only needed to fulfil technical functions, but are in direct focus of the customer’s perception. The perceived quality is based on all sensory data collected by the human perceptual system. Surfaces express design intent and craftsmanship by their visual appearance. Haptic features supervene when materials are touched. And even smell has an influence on the perception of ambience. Although sound is generated nearly every time when fingers slide across a surface, touch-sounds have been disregarded so far. In various cases, these contact sounds are clearly audible. As essential sound responses to haptic activity, they can degrade perceived quality. A method has been developed for a standardized generation of touch-sounds.
2017-03-28
Journal Article
2017-01-0011
Kesav Kumar Sridharan, Swaminathan Viswanathan
Abstract Current generation automobiles are controlled by electronic modules for performing various functions. These electronic modules have numerous semiconductor devices mounted on printed circuit boards. Solders are generally used as thermal interface material between surface mount devices and printed circuit boards (PCB) for efficient heat transfer. In the manufacturing stage, voids are formed in solders during reflow process due to outgassing phenomenon. The presence of these voids in solder for power packages with exposed pads impedes heat flow and can increase the device temperature. Therefore it is imperative to understand the effect of solder voids on thermal characteristics of semiconductor devices. But the solder void pattern will vary drastically during mass manufacturing. Replicating the exact solder void pattern and doing detail simulation to predict the device temperature for each manufactured module is not practical.
2017-03-28
Technical Paper
2017-01-0177
Lili Feng, Predrag Hrnjak
Abstract This paper presents the study of refrigerant charge imbalance between A/C (cooling) mode and HP (heating) mode of a mobile reversible system. Sensitivities of cooling and heating capacity and energy efficiency with respect to refrigerant charge were investigated. Optimum refrigerant charge level for A/C mode was found to be larger than that for HP mode, primarily due to larger condenser size in A/C mode. Refrigerant charge retention in components at both modes were measured in the lab by quick close valve method. Modeling of charge retention in heat exchangers was compared to experimental measurements. Effect of charge imbalance on oil circulation was also discussed.
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
2017-01-0527
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
2017-01-0629
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
2017-01-1365
Michael Larsen
Abstract Vehicle certification requirements generally fall into 2 categories: self-certification and various forms of type approval. Self-certification requirements used in the United States under Federal Motor Vehicle Safety Standards (FMVSS) regulations must be objective and measurable with clear pass / fail criteria. On the other hand, Type Approval requirements used in Europe under United Nations Economic Commission for Europe (UNECE) regulations can be more open ended, relying on the mandated 3rd party certification agency to appropriately interpret and apply the requirements based on the design and configuration of a vehicle. The use of 3rd party certification is especially helpful when applying regulatory requirements for complex vehicle systems that operate dynamically, changing based on inputs from the surrounding environment. One such system is Adaptive Driving Beam (ADB).
2017-03-28
Technical Paper
2017-01-0175
Jing He, Bill Johnston, Debasish Dhar, Loren Lohmeyer
The natural refrigerant, R744 (CO2), remains a viable solution to replace the high GWP refrigerant R134a which is to be phased out in light-duty vehicles in EU and US market. In this study, thermodynamic analysis is performed on a R744 parallel compression system to evaluate its potential in automotive climate control. The model adopts a correlation of isentropic efficiency as a function of compression ratio based on a prototype R744 MAC compressor and accounts for the operating limits defined in the latest DIN specifications. Optimization is run over typical MAC operating conditions which covers both transcritical and subcritical domain. Comparing to the conventional single compression cycle, effectiveness of parallel compression is found most pronounced in low evaporating temperature and high ambient conditions, with up to 21% increase in COP and 5.3 bar reduction in discharge pressure observed over the considered parametric range.
2017-03-28
Technical Paper
2017-01-0172
Suhas Venkatappa, Manfred Koberstein, Zhengyu Liu
Abstract The refrigerant transition from HFC-134a to HFO-1234yf has proven to be more challenging on controlling refrigerant flow-induced noises generated from automotive air-conditioning (A/C) systems than originally anticipated. The objectives of this paper are to describe the noise issues with HFO-1234yf, understand the mechanisms and key factors affecting HFO-1234yf refrigerant flow-induced noise. Finally, the countermeasures and guidelines for attenuating and suppressing the noise are presented.
2017-03-28
Technical Paper
2017-01-0448
Prakash T. Thawani, Stephen Sinadinos, John Zvonek
Abstract With the advent of EVs/HEVs and implementation of Idle-Stop-Start (ISS) technologies on internal combustion engine (ICE) driven cars/trucks to improve fuel economy and reduce pollution, refrigerant sub-system (RSS) induced noise phenomena like, hissing, gurgling and tones become readily audible and can result in customer complaints and concerns. One of the key components that induce these noise phenomena is the Thermostatic Expansion Valve (TXV). The TXV throttles compressed liquid refrigerant through the evaporator that results in air-conditioning (A/C) or thermal system comfort for occupants and dehumidification for safety, when needed. Under certain operating conditions, the flow of gas and/or liquid/gas refrigerant at high pressure and velocity excites audible acoustical and structural modes inherent in the tubing/evaporator/HVAC case. These modes may often get masked and sometimes enhanced by the engine harmonics and blower noise.
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
2017-01-0937
David Culbertson, James Pradun, Magdi Khair, Jeff Diestelmeier
Abstract Tightening regulations throughout the world demand a reduction in fuel consumption and NOX emission levels, creating an increasing need for additional heat for SCR aftertreatment. A durable and low cost heating system is needed for vehicles with hybrid or 24Vdc electricity. Recent development efforts have resulted in much smaller and lower cost heating systems for electrical systems ranging from 400 to 24Vdc. Test results demonstrate the feasibility of reducing the size of the heater and the relationship of heater power to the amount of time required to heat the exhaust. Intelligent solid state switching enables the heater to be smaller without compromising durability.
2017-03-28
Journal Article
2017-01-1520
Teddy Hobeika, Peter Gullberg, Simone Sebben, Lennart Lofdahl
Abstract Quantification of heat exchanger performance in its operative environment is in many engineering applications an essential task, and the air flow rate through the heat exchanger core is an important optimizing parameter. This paper explores an alternative method for quantifying the air flow rate through compact heat exchangers positioned in the underhood of a passenger car. Unlike conventional methods, typically relying on measurements of direct flow characteristics at discrete probe locations, the proposed method is based on the use of load-cells for direct measurement of the total force acting on the heat exchanger. The air flow rate is then calculated from the force measurement. A direct comparison with a conventional pressure based method is presented as both methods are applied on a passenger car’s radiator tested in a full scale wind tunnel using six different grill configurations.
2017-03-28
Journal Article
2017-01-0120
Yoichiro Kawamoto, Gota Ogata, Zhiwei Shan
Abstract This study reports on a new generation ECS (Ejector Cycle System) which includes a highly efficient ejector and a novel system configuration. The ejector is working as a fluid jet pump that recovers expansion energy which is wasted in the conventional refrigeration cycle decompression process, and converts the recovered expansion energy into pressure energy and raises the compressor suction pressure. Consequently, the ejector system can reduce power consumption of the compressor by using the above mentioned pressure-rising effect and improve energy efficiency of the refrigeration cycle. The ejector consists of a nozzle, a suction section, a mixing section and a diffuser. The objective of this study is to improve actual fuel economy of all vehicles by ejector technology. The previous generation ECS was reported in 2012 SAE World Congress1. Now, a new generation ECS has been successfully developed and released in the market for Mobile Air Conditioning systems as of 2013.
2017-03-28
Journal Article
2017-01-0122
Gursaran D. Mathur
Water drainage characteristics are dependent on the design of the evaporator: specifically the design of the fins and plates along with hydrophilic coating. A part of the hydrophilic coating washes off with the moisture that condenses over the evaporator core from the air-stream. Hence, water drainage characteristics of an evaporator changes with the vehicle mileage or the age of the vehicle. Since a part of the hydrophilic coating washes away, more water is retained within the evaporator at this condition. Hence, the effectiveness of the evaporator drainage deteriorates with the age of the vehicles. At this condition, the contact angle measured at the plate increases. Author has conducted an experimental study to measure the effectiveness of hydrophilic coating from evaporators taken out from arid (9 cores) and humid areas (16 cores) as a function of vehicle mileage or vehicle age. Contact angles and water retention were measured for a number of evaporators from different OEMs.
2017-03-28
Journal Article
2017-01-0147
Brian Sweetman, Ingo Schmitz, Burkhard Hupertz, Nathanael Shaw, John Goldstein
Abstract Driven by the demand to continuously reduce the development time of new vehicles, it is of critical importance to robustly develop design and packaging concepts early within a new vehicle program using CAE methods. As the underhood and underbody package is constantly getting tighter and the engine power increases, the development of a sophisticated heat protection concept requires much more attention. For many years, heat protection CAE is an integral part of the vehicle development at Ford. However, due to challenges related to transient analysis, e.g. high numerical effort, simulation of transient buoyancy driven airflow (thermal soak), and dependency on high quality thermal material properties, heat protection CAE was primarily focused on steady state vehicle operating conditions.
2017-03-28
Journal Article
2017-01-0165
Jingwei Zhu, Stefan Elbel
Abstract Expansion work recovery by two-phase ejector is known to be beneficial to vapor compression cycle performance. However, one of the biggest challenges with ejector vapor compression cycle is that the ejector cycle performance is sensitive to working condition changes which are common in many applications, including automotive AC systems. Different working conditions require different ejector geometries to achieve maximum performance. Slightly different geometries may result in substantially different COPs under the same conditions. Ejector motive nozzle throat diameter (motive nozzle restrictiveness) is one of the key parameters that can significantly affect COP. This paper presents the experimental investigation of a new motive nozzle restrictiveness control mechanism for two-phase ejectors used in vapor compression cycles, which has the advantages of being simple, potentially less costly and less vulnerable to clogging.
2017-03-28
Journal Article
2017-01-0170
Aditya Velivelli, Daniel Guerithault, Stefan Stöwe
Abstract Seat cooling and heating strategies have enhanced human thermal comfort in automotive environments. Cooling/heating strategies also need to focus on the distribution of the seat cooling/heating power across the seat and the effect of such distributions on human thermal comfort. This paper studies the effect of active cooling combined with ventilation only strategy on thermal comfort. As part of the study, heat flux between the occupant and seat is mapped and is correlated to a step increase in the occupant’s local thermal comfort of body segments in contact with seat. A human physiological model and the Berkeley comfort model were combined to determine power and optimum placement of cooling to effectively cool an occupant using a climate control seat in a warm environment. This leads to a new approach using asymmetric seat cooling to distribute cooling power resulting in improved and balanced subjective comfort than traditional climate seat and ventilation technologies.
2017-03-28
Journal Article
2017-01-0178
Mark Hepokoski, Allen Curran, Sam Gullman, David Jacobsson
Abstract Passive sensor (HVAC) manikins have been developed to obtain high-resolution measurements of environmental conditions across a representative human body form. These manikins incorporate numerous sensors that measure air velocity, air temperature, radiant heat flux, and relative humidity. The effect of a vehicle’s climate control system on occupant comfort can be characterized from the data collected by an HVAC manikin. Equivalent homogeneous temperature (EHT) is often used as a first step in a cabin comfort analysis, particularly since it reduces a large data set to a single intuitive number. However, the applicability of the EHT for thermal comfort assessment is limited since it does not account for human homeostasis, i.e., that the human body actively counter-balances heat flow with the environment to maintain a constant core temperature.
2017-03-28
Journal Article
2017-01-1305
Yucheng Liu, Jeremy Batte, Zachary Collins, Jennifer Bateman, John Atkins, Madelyn Davis, David Salley, Cindy L. Bethel, John Ball, Christopher Archibald
Abstract A robot mining system was developed by the State Space Robotic undergraduate student design team from Mississippi State University (MSU) for the 2016 NASA Robotic Mining Competition. The mining robot was designed to traverse the Martian chaotic terrain, excavate a minimum of 10 kg of Martian regolith and deposit the regolith into a collector bin within 10 minutes as part of the competition. A Systems Engineering approach was followed in proceeding with this design project. The designed mining robot consisted of two major components: (1) mechanical system and (2) control system. This paper mainly focuses on the design and assessment process of the mechanical system but will also briefly mention the control system so as to evaluate the designed robotic system in its entirety. The final designed robot consisted of an aluminum frame driven by four motors and wheels. It utilized a scoop and lifting arm subsystem for collecting and depositing Martian regolith.
2017-03-28
Journal Article
2017-01-1302
Hyung In Yun, Jae Kyu Lee, Jae Hong Choi, MyoungKwon Je, Junhyuk Kim
Abstract A sliding door is one of the car door systems, which is generally applied to the vans. Compared with swing doors, a sliding door gives comfort to the passengers when they get in or out the car. With an increasing number of the family-scale activities, there followed a huge demand on the vans, which caused growing interests in the convenience technology of the sliding door system. A typical sliding door system has negative effects on the vehicle interior package and the operating effort. Since the door should move backward without touching the car body, the trajectory of the center rail should be a curve. The curve-shaped center rail infiltrates not only the passenger shoulder room, but also the opening flange curve, which results in the interior package loss. Moreover, as the passenger pulls the door outside handle along the normal direction of the door outer skin, the curved rail causes the opening effort loss.
Viewing 91 to 120 of 8585