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2016-04-05
Technical Paper
2016-01-0657
T Sethuramalingam, Chandrakant Parmar, Sashikant Tiwari
Abstract DFSS is a disciplined problem prevention approach which helps in achieving the most optimum design solution and provides improved and cost effective quality products. This paper presents the implementation of DFSS method to design a distinctive cooling system where engine is mounted in the rear and radiator is mounted in the front of the car. In automobile design, a rear-engine design layout places the engine at the rear of the vehicle. This layout is mainly found in small, entry level cars and light commercial vehicles chosen for three reasons - packaging, traction, and ease of manufacturing. In conventional Passenger cars, a radiator is located close to the engine for simple packaging and efficient thermal management. This paper is about designing a distinctive cooling system of a car having rear mounted engine and front mounted radiator.
2016-04-05
Technical Paper
2016-01-0664
Ahmed E. Hassaneen, Wael I. A. Aly, Gamal Bedair, Mohammed Abdussalam
Abstract The thermal performance of an ammonia-water-hydrogen absorption refrigeration system using the waste exhaust gases of an internal combustion diesel engine as energy source was investigated experimentally. An automotive engine was tested in a bench test dynamometer, with the absorption refrigeration system adapted to the exhaust pipe via a heat exchanger. The engine was tested for different torques (15 N.m, 30 N.m, and 45 N.m). The exhaust gas flow to the heat exchanger built on the generator was controlled manually using two control valves. The refrigerator reached a steady state temperature between 10 and 14.5°C about 3.5 hours after system start up, depending on engine load. The maximum coefficient of performance was 0.10 obtained for the controlled exhaust mass flow case at torque 30 Nm after 3hrs from system startup.
2016-04-05
Technical Paper
2016-01-0681
Cyrille Constensou, Vincent Collee
Abstract Increasing the efficiency of internal combustion engines is mandatory to meet ever more stringent regulations. The implementation of very high compression ratio (> 15:1) is the key to take full advantage of the association of Variable Compression Ratio (VCR) and Variable Valve Actuation (VVA) in the implementation of Miller-Atkinson cycle, leading to higher thermodynamic efficiency and thus better fuel consumption benefits. VVA systems allow differentiating geometric compression ratio and effective compression ratio. They theoretically permit to maximize expansion ratio (i.e. geometric compression ratio) while keeping an effective compression ratio in accordance with the constraints of the knocking limits, but with a limitation on the reachable maximum Brake Mean Effective Pressure (BMEP) at low compression ratio and the associated downsizing.
2016-04-05
Journal Article
2016-01-0178
Feng Zhou, Ercan Dede, Shailesh Joshi
Abstract Rankine cycle (RC) is a thermodynamic cycle that converts thermal energy into mechanical work, which is commonly found in thermal power generation plants. Recently, there are many studies focusing on applying Rankine cycle to recover low-grade waste heat. On-road vehicles, which convert around one third of the fuel energy into useful mechanical energy for propulsion, are moving energy conversion systems that generate considerable waste heat. It was found from many research studies that Rankine cycle has a great potential to be applied to harvest waste heat from automobiles. However, different from other low-grade waste heat sources, vehicles have limited space for the RC system integration and the waste heat is relatively unstable. In the current paper, the efforts in the past few decades related to applying RC to on-road vehicles, specifically passenger cars, are reviewed.
2016-04-05
Technical Paper
2016-01-0256
Hideaki Nagano, Kenji Tomita, Yasuhiro Tanoue, Yuji Kobayashi, Itsuhei Kohri, Shinsuke Kato
Abstract In the winter, windshield glass fogging must be prevented through the intake of outdoor air into a vehicle. However, the corresponding energy loss via the ventilation system cannot be ignored. In the present study, the defogging pattern on the windshield is evaluated and the water vapor transportation in the flow field in the vehicle is analyzed in order to investigate the ventilation load by means of a numerical simulation. Some examined cases involve new outlet positions. Additionally, a new, energy-saving air supply method for defogging, with so-called “double-layer ventilator”, is proposed. In this method, one air jet layer is obtained via a conventional defogging opening in the vicinity of the windshield, supplying an outdoor air intake. The other jet consists of recirculated air that covers the outdoor air, preventing it from mixing with the surrounding air.
2016-04-05
Technical Paper
2016-01-0257
Lili Feng, Predrag Hrnjak
Abstract This paper presents the experimentally obtained performance characteristics of an air conditioning-heat pump system that uses heat exchangers from a commercially available Nissan Leaf EV. It was found that refrigerant charge needed for cooling operation was larger than that for heating function with the test setup. The effects of: a). indoor air flow rate, b). outdoor air flow rate, and c). compressor speed on heating capacity and energy efficiency were explored and presented. Appropriate opening size of expansion valve that controlled subcooling for better energy efficiency was discussed and results were presented. Expansion valve opening size also strongly affected charge migration. Warm-up tests at different ambient conditions showed the necessity of a secondary heater to be reserved for very low ambient temperature.
2016-04-05
Technical Paper
2016-01-0255
Yinhua Zheng
This paper addresses R1234yf A/C system performance impacted by condenser airflow passage blockages of nonhotspot and hotspot objects. With the modern vehicle design trend, more and more chances exist in blocking condenser airflow passages by objects such as TOC (transmission oil cooler) or fine grills etc. These objects create hotspots and narrowed airflow passages to the condenser and result in A/C performance degradation. It is important to understand the specific area of the condenser which is most impacted by a blockage so this area can be avoided in the design/packaging of front end components. In addition, it is important to understand the magnitude of performance loss associated with the specific areas of blockage. As a result of this understanding, optimal design locations for these blockages (including hotspots and grilles) can be proposed in order to mitigate the impact on A/C cooling performance.
2016-04-05
Technical Paper
2016-01-0254
Gursaran D. Mathur
Field tests were conducted on a late full sized sedan with the HVAC unit operating in both Recirculation and OSA modes to monitor build-up of the CO2 concentration inside the cabin and its influence on occupant’s fatigue and alertness. These tests were conducted during 2015 summer on interstate highways with test durations ranging from 4 to 7 hours. During the above tests, fatigue or tiredness of the occupants (including CO2 levels) was monitored and recorded at 30 min intervals. Based on this investigation it is determined that the measured cabin concentration levels reaches ASHRAE (Standard 62-1999) specified magnitudes (greater than 700 ppm over ambient levels) with three occupants in the vehicle. Further, the occupants did show fatigue when the HVAC unit was operated in recirculation mode in excess of 5 hours. Further details have been presented in the paper.
2016-04-05
Technical Paper
2016-01-0259
Kaushal Kumar Jha, Sarveshwar Reddy Mulamalla, Anil Anugu
Abstract The main function of an air conditioning system in a vehicle is to provide the thermal comfort to the occupant at minimum possible energy consumption in all environmental conditions. To ensure the best possible thermal comfort, air conditioning system is optimized on various parameters like heat load, air flow distribution, glass area, trim quality, insulations and cabin leak rate. A minimum cabin leakage is regulatory requirements to ensure the air quality of cabin. Anything above the minimum cabin leak rate ultimately turn into reduced thermal comfort and additional energy consumption. The additional energy consumption to maintain the required thermal comfort in the cabin due to cabin leakage affects the fuel efficiency severely. In the present study, the effect of cabin leakage on fuel efficiency and thermal comfort is studied in details by varying the cabin leakage through mechanical means.
2016-04-05
Technical Paper
2016-01-0239
Li Zhou, Gangfeng Tan, Xuexun Guo, Ming Chen, Kangping Ji, Zhilei Li, Zhongjie Yang
Abstract The hydraulic retarder is an auxiliary braking device used in heavy duty vehicle. It generates braking forceby liquid damping effect and makes inertial energy into thermal energy of the transmission medium when the vehicleis in thedownhill. The traditional thermal management system of the hydraulic retarder dissipates the heat of transmission medium out of the vehicle directly, which causes a big waste of energy, meanwhilethe thermal management system components need to consume engine power. This study applies organic Rankine cycle (ORC)cooling system to meet the high power cooling requirements of the hydraulic retarder and recover waste heat energy from the transmission medium at the same time and then supply energy to the thermal management system, which could save the parasitic power of the engine and improve the comprehensive energy utilization ratio of the vehicle.
2016-04-05
Technical Paper
2016-01-0240
Ruobing Zhan, Gangfeng Tan, Bo Yang, Zhiwei Zhang, Tie Wang, Cenyi Liu, Xintong Wu, Yanjun Ren, Haobo Xu
Abstract The Organic Rankine Cycle System (ORC) is an effective means to use the solar energy. The system adopts the solar energy on the car roof as the heat source to make the ORC work and drive the thermoelectric air-conditioner. It can improve the entering comfort on the parking condition and the vehicle energy utilization efficiency. In this research, the system comprehensively applied the principle of sunshine concentration, heat collection and photo electricity. Then considering the working condition and performance features of ORC system, the car roof was designed to have a compact structure, through which the efficiency of the solar vehicle system could be improved. Firstly, the research analyzed the heat source temperature and the heat flux impact on the output power of the ORC system. After that, the performance of heat collection was identified according to the given thermoelectric air-condition’s power requirements.
2016-04-05
Technical Paper
2016-01-0237
Ge-Qun Shu, Xuan Wang, Hua Tian
Abstract Because of the great resources potential and the feature of low pollution of gaseous fuel, gaseous fuel internal combustion engines (gas engines) have been paid more and more attention. However, their average thermal efficiency is just about 30-40% wasting a huge amount of energy by exhaust, cooling water and so on, so waste heat recovery is very meaningful. Both the RC (steam Rankine Cycle) and the ORC (Organic Rankine Cycle) are regarded as the suitable way of WHR (waste heat recovery) for internal combustion engines. Therein, RC is usually used in large engines. The WHR system is always designed at rated work condition, while the gas engine may often work at different conditions. This makes the property of the waste heat source change, which affects the performance of WHR system, so it is very important to research its performance at variable working conditions.
2016-04-05
Technical Paper
2016-01-0244
Tim J. LaClair, Zhiming Gao, Omar Abdelaziz, Mingyu Wang, Edward Wolfe, Timothy Craig
Abstract Cabin heating of current electric vehicle (EV) designs is typically provided using electrical energy from the traction battery, since waste heat is not available from an engine as in the case of a conventional automobile. In very cold climatic conditions, the power required for space heating of an EV can be of a similar magnitude to that required for propulsion of the vehicle. As a result, its driving range can be reduced very significantly during the winter season, which limits consumer acceptance of EVs and results in increased battery costs to achieve a minimum range while ensuring comfort to the EV driver. To minimize the range penalty associated with EV cabin heating, a novel climate control system that includes thermal energy storage from an advanced phase change material (PCM) has been designed for use in EVs and plug-in hybrid electric vehicles (PHEVs).
2016-04-05
Technical Paper
2016-01-0245
Jingwei Zhu, Stefan Elbel
Abstract Increasing energy costs justify research on how to improve utilization of low-grade energy that is abundantly available as waste heat from many thermodynamic processes such as internal combustion engine cycles. One option is to directly generate cooling through absorption/adsorption or vapor jet ejector cycles. As in the case of power generation cycles, cooling cycle efficiencies would increase if the heat input were available at higher temperature. This paper assesses the feasibility of a novel idea that uses a vortex tube to increase the available temperature levels of low-grade heat sources. The desired temperature increase is achieved by sending a stream of vapor that was heated by the waste heat source through a vortex tube, which further elevates the temperature used in a heat driven ejector cooling cycle.
2016-04-05
Technical Paper
2016-01-0241
Sina Shojaei, Simon Robinson, Andrew McGordon, James Marco
Abstract The power demand of air conditioning in PHEVs is known to have a significant impact on the vehicle’s fuel economy and performance. Besides the cooling power associated to the passenger cabin, in many PHEVs, the air conditioning system provides power to cool the high voltage battery. Calculating the cooling power demands of the cabin and battery and their impact on the vehicle performance can help with developing optimum system design and energy management strategies. In this paper, a representative vehicle model is used to calculate these cooling requirements over a 24-hour duty cycle. A number of pre-cooling and after-run cooling strategies are studied and effect of each strategy on the performance of the vehicle including, energy efficiency, battery degradation and passenger thermal comfort are calculated. Results show that after-run cooling of the battery should be considered as it can lead to significant reductions in battery degradation.
2016-04-05
Technical Paper
2016-01-0248
Mingyu Wang, Edward Wolfe, Timothy Craig, Tim J. Laclair, Omar Abdelaziz, Zhiming Gao
Abstract 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 the traction battery. In very cold climatic conditions, the power required to heat the EV cabin can be of a similar magnitude to that required for propulsion of the vehicle. As a result, the driving range of an EV can be reduced very significantly during winter months, which limits consumer acceptance of EVs and results in increased battery costs to achieve a minimum range while ensuring comfort to the EV driver. To minimize the range penalty associated with EV cabin heating, a novel climate control system that includes thermal energy storage has been designed for use in EVs and plug-in hybrid electric vehicles (PHEVs). The system uses the stored latent heat of an advanced phase change material (PCM) to provide cabin heating.
2016-04-05
Technical Paper
2016-01-0249
Balashunmuganathan Vasanth, Kumar Sathish, Murali Govindarajalu, Mohsin Khan
In recent years reducing the automobile HVAC (Heating Ventilation and automobile conditioning) noise inside the vehicle cabin is one of the main criterions for all OEMs to provide comfort level to the passengers. The primary function of the HVAC is to deliver more air to the cabin with less noise generation for various blower speeds. Designing the optimum HVAC with less noise is one of the major challenges for all automotive manufacturers and HVAC suppliers. During the design stage, physical parts are not available and hence the simulation technique helps to evaluate the noise level of HVAC. In this study, a computational 1D (one dimensional) analysis is carried out to compute the airflow noise originated from the HVAC unit and propagated to the passenger cabin. Modeling has been done using unigraphics and the analysis is carried out using the commercial 1D software GT suite.
2016-04-05
Technical Paper
2016-01-0247
Jiu Xu, Predrag Hrnjak
Abstract Automotive air conditioning compressor produces an annular-mist flow consisting of gas-phase refrigerant flow with oil film and oil droplets. This paper reports a method to calculate the oil retention and oil circulation ratio based on oil film thickness, wave speed, oil droplet size, oil droplet speed, and mass flow rate. Oil flow parameters are measured by high-speed camera capture and video processing in a non-invasive way. The estimated oil retention and oil circulation ratio results are compared quantitatively with the measurements from system experiments under different compressor outlet gas superficial velocity. The agreement between video result and sampling measurement shows that this method can be applied in other annular-mist flow analysis. It is also shown that most of the oil exists in film from the mass point of view while oil droplets contributes more to the oil mass flow rate because they travel in a much higher speed.
2016-04-05
Technical Paper
2016-01-0253
Jun Li, Predrag Hrnjak
Abstract This paper presents the experimental analysis of separation in vertical headers based on flow visualization. Two-phase separation phenomena inside the header is observed and quantified. Driving forces are analyzed to study the mechanisms for two-phase flow motion and flow regimes. Main tube of the header is made of clear PVC for visualization study. R-134a is used as the fluid of interest and the mass flux from the inlet pass is 55 kg/m2s - 195 kg/m2s. Potential ways to improve two-phase separation are discussed. A model is built to show how separation brings potential benefits to MAC heat exchangers by arranging the flow path.
2016-04-05
Technical Paper
2016-01-0252
Huize Li, Predrag Hrnjak
Abstract This paper presents the visualization of periodic reverse flow in tubes of an automobile microchannel evaporator. Two microchannel tubes in an off-the-shelf evaporator are modified so that the leading edges are transparent and the rest of the area remains unchanged, providing realistic air heating. Flow visualizations in air heated aluminum tubes and electric heating glass tube are compared and similar flow physics is identified. A mechanistic model of flow reversal is developed. The model is capable of simulating bubble generation, growth coalescence and reverse. The validation against experimental visualization is on the way.
2016-04-05
Technical Paper
2016-01-0250
Filip Nielsen, Åsa Uddheim, Jan-Olof Dalenbäck
Abstract In recent years fuel consumption of passenger vehicles has received increasing attention by customers, the automotive industry, regulatory agencies and academia. However, some areas which affect the fuel consumption have received relatively small interest. One of these areas is the total energy used for vehicle interior climate which can have a large effect on real-world fuel consumption. Realistic combinations of energy saving measures were evaluated regarding the total energy use for vehicle interior climate using a one dimensional (1D) simulation model. The 1D simulation model included sub models of the passenger compartment, the air-handling unit, the Air Conditioning (AC) system, engine and engine cooling system. A test cycle representative for real-world conditions was developed. The test cycle included tests in cold, intermediate and warm conditions and the results were weighted with the estimated use in each condition.
2016-04-05
Technical Paper
2016-01-0306
Heeseung Yang, Hyunkwon Jo, Hyunchul Lee, Hyunmin Park, JaeMin Park
Abstract The Automotive Interior Parts offer convenience and riding comfort for passengers. One of its main features is that it is placed in a conspicuous place. Therefore, automotive interior part manufacturer attach importance to appearance quality. Additionally, appearance quality of Interior Parts is more important as the senses of passenger heighten. Most Automotive Interior Parts manufactured by Injection Molding to mass produce it with complex geometry. But there are numerous defects in method of Injection Molding. Especially, large products like automotive interior parts are disadvantage. A typical example of defects is weld line, sink mark, short shot. These are having an adverse effect on the appearance quality as well as another quality like BSR (Buzz Squeak Rattle) and Side impact performance. In order to improve problem, molding has been modified and spray coating has been done over the past.
2016-04-05
Journal Article
2016-01-0280
Alaa El-Sharkawy, Amr Sami, Abd El-Rahman Hekal, Dipan Arora, Masuma Khandaker
Abstract In this paper, the development of a transient thermal analysis model for the exhaust system is presented. Given the exhaust gas temperature out of the engine, a software tool has been developed to predict changes in exhaust gas temperature and exhaust surface temperature under various operating conditions. The software is a thermal solver that will predict exhaust gas and wall surface temperatures by modeling all heat transfer paths in the exhaust system which includes multi-dimensional conduction, internal forced/natural convection, external forced/natural convection, and radiation. The analysis approach involves the breaking down of the thermal system into multiple components, which include the exhaust system (manifold, takedown pipe, tailpipe, etc.), catalytic converter, DPF (diesel particulate filter), if they exist, thermal shields, etc. All components are modeled as 1D porous and 1D non-porous flow streams with 3D wall layers (solid and air gaps).
2016-04-05
Journal Article
2016-01-0281
Alaa El-Sharkawy, Dipan Arora, Abd El-Rahman Hekal, Amr Sami, Muhannad Hendy
Abstract In this paper, transient component temperatures for the vehicle under-hood and underbody are estimated. The main focus is on the component temperatures as a result of radiation from exhaust, convection by underbody or under-hood air and heat conduction through the components. The exhaust surface temperature is simulated as function of time and for various vehicle duty cycles such as city traffic, road load and grade driving conditions. At each time step the radiation flux to the surrounding component is estimated, heat addition or removal by convection is evaluated based on air flow, air temperature and component surface area. Simulation results for under-hood and underbody components are compared against vehicle test data. The comparison shows very good agreement between simulated and measured component temperatures under both steady state and transient conditions.
2016-04-05
Journal Article
2016-01-0282
Julio Carrera
Abstract Recent emissions standards have become more restrictive in terms of CO2 and NOx reduction. This has been translated into higher EGR rates at higher exhaust gas temperatures with lower coolant flow rates for much longer lifetimes. In consequence, thermal load for EGR coolers has been increasing and the interaction of boiling with thermal fatigue is now a critical issue during development. It is almost impossible to avoid localized boiling inside an EGR cooler and, in fact, it would not be strictly necessary when it is below the Critical Heat Flux (CHF). However when CHF is exceeded, film boiling occurs leading to the sudden drop of the heat transfer rate and metal temperature rise. In consequence, thermal stress increases even when film boiling is reached only in a small area inside the part. It is very difficult to accurately predict under which conditions CHF is reached and to establish the margins to avoid it.
2016-04-05
Technical Paper
2016-01-0283
Joydip Saha, Harry Chen, Sadek Rahman
Abstract More stringent federal emission regulations and fuel economy requirements have driven the automotive industry toward more sophisticated vehicle thermal management systems in order to best utilize the waste heat and minimize overall power consumption. With all new technologies and requirements, how to properly design, optimize, and control the vehicle thermal and cooling systems become great challenges to automotive engineers. Model based approach has become essential to the new thermal management system architectures design and evaluation of the optimal system solutions. This paper will discuss how the model based vehicle thermal system simulation tools have been developed from analytical & empirical data, and have been used for assessment and development of new thermal management system architectures.
2016-04-05
Technical Paper
2016-01-0321
Manjil Kale, Rajat Diwan, Fnu Renganathan Dinesh, Mark Benton, Prasanth Muralidharan, Paul Venhovens, Johnell Brooks, ChunKai Liu, Julie Jacobs, Craig Payne
Abstract The Deep Orange framework is an integral part of the graduate automotive engineering education at Clemson University International Center for Automotive Research (CU-ICAR). The initiative was developed to immerse students into the world of an OEM. For the 6th generation of Deep Orange, the goal was to develop an urban utility/activity vehicle for the year 2020. The objective of this paper is to explain the interior concept that offers a flexible interior utility/activity space for Generation Z (Gen Z) users. AutoPacific data were first examined to define personas on the basis of their demographics and psychographics. The resulting market research, benchmarking, and brand essence studies were then converted to consumer needs and wants, to establish technical specifications, which formed the foundation of the Unique Selling Points (USPs) of the concept.
2016-04-05
Technical Paper
2016-01-0564
Pengfei Lu, Chris Brace, Bo Hu
Abstract The turbo-compounding has been extensively researched as a mean of improving the overall thermal efficiency of the internal combustion engine. Many of the studies aiming to optimize the turbo-compounding system lead to the unified conclusion that this approach is more suitable for the operation under constant high load condition, while it has little effect on improving the fuel economy under low load conditions. Besides, in a traditional series turbo-compounding engine, the increased back pressure unavoidably results in a serious parasitic load to the system by increasing the resistance to the scavenging process. In order to improve this situation, a novel turbo-compounding arrangement has been proposed, in which the turbocharger was replaced by a continuously variable transmission (CVT) coupled supercharger (CVT superchargedr) to supply sufficient air mass flow rate to the engine at lower engine speeds.
2016-04-05
Technical Paper
2016-01-0450
Somnath Sen, Paulson Parayil
Abstract In order to ensure a comfortable space inside the cabin, it is very essential to design an efficient heating ventilating and air-conditioning (HVAC) system which can deliver uniform temperature distribution at the exit. There are several factors which impact on uniformity of temperature distribution. Airflow distribution is one of the key parameter in deciding the effectiveness of temperature distribution. Kinematics links and linkage system typically termed as ‘mechanism’ is one of the critical sub-systems which greatly affects the airflow distribution. It is not the temperature uniformity but also the HVAC temperature linearity also depends on airflow distribution. Hence the design of mechanism is incomparably of paramount importance to achieve the desired level of airflow distribution at HVAC exit. The present paper describes the design methodology of automotive HVAC mechanism system.
2016-04-05
Technical Paper
2016-01-0480
Weiguo Zhang, Mark Likich, Mac Lynch, John White
Abstract The noise radiated from the snorkel of an air induction system (AIS) can be a major noise source to the vehicle interior noise. This noise source is typically quantified as the snorkel volume velocity which is directly related to vehicle interior noise through the vehicle noise transfer function. It is important to predict the snorkel volume velocity robustly at the early design stage for the AIS development. Design For Six Sigma (DFSS) is an engineering approach that supports the new product development process. The IDDOV (Identify-Define-Develop-Optimize-Verify) method is a DFSS approach which can be used for creating innovative, low cost and trouble free products on significant short schedules. In this paper, an IDD project which is one type of DFSS project using IDDOV method is presented on developing a robust simulation process to predict the AIS snorkel volume velocity. First, the IDDOV method is overviewed and the innovative tools in each phase of IDDOV are introduced.
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