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Viewing 91 to 120 of 10079
2015-04-14
Technical Paper
2015-01-0362
Neal Lawrence, Stefan Elbel
Abstract Much attention has been given in recent years to the use of two-phase ejectors and particularly to the performance of the standard ejector cycle with a liquid-vapor separator. However, this cycle may not be the best choice for automotive applications due to the large size required by an efficient separator as well as the cycle's performance at conditions of lower ejector potential. A limited amount of recent research has focused on alternate two-phase ejector cycles that may be better suited for automotive applications. One of these cycles, using the ejector to allow for evaporation at two different temperatures and eliminating the need for a separator, will be the subject of investigation in this paper. Previous investigations of this cycle have been mainly theoretical or experimental; this paper aims to provide a numerical analysis of the effect of evaporator design on the performance of the ejector cycles.
2015-04-14
Technical Paper
2015-01-0367
Zhiqiang Hu, Gangfeng Tan, Zhilei Li, Haobo Xu, Wenhui Huang, Yifan Ye
Abstract The cabin air temperature increases quickly and can reach 80°C when the vehicle parks in the summer sunlight which has the bad influence on the occupants entering comfort. Some luxury vehicles, like Audi A8[1], reduce the internal temperature through operating air-condition in advance or using on-board battery to drive the cabin ventilator, which requires relatively complex control system and limits the system's operating time because of energy consumption. This research adopts the solar wing as the ventilation power supply and accomplishes the cabin real-time heat rejection by achieving the steady air circulation for both inside and outside environment. First, the static thermal transfer model of the crew cabin is established. Then, on the basis of the parameters of the prototype ventilation pipe, the ventilation model for the outside circulation is built.
2015-04-14
Technical Paper
2015-01-0368
Janampally Sandeep Kumar Reddy, Shailendra Deopa, Abhay Sharma, Piyush Aggarwal
Abstract Bumper opening area projected on condenser to total condenser core area is referred to as condenser opening area. The condenser opening area plays a vital role in A/C Performance of vehicle particularly during idling and initial cooling of vehicle. This paper presents detail study on effects of condenser opening area on A/C performance. Based on theory, the effect of condenser opening area is studied and it is validated by experimental results. Depending on these results an optimum value of condenser opening area required for best A/C performance is concluded.
2015-04-14
Technical Paper
2015-01-0365
Gursaran D. Mathur
Abstract Experimental studies have been conducted to determine the energy stored in vehicle's Cockpit Module (CPM) at cold soaking conditions for a MY2012 production vehicle. Detailed analysis has been done in this paper to show the influence of energy stored in various components (e.g., Instrument panel, HVAC system, heat exchanger, wire harness, etc.) contained within the CPM unit. Experiments conducted show that the instrument panel stores the maximum amount of energy at a given temperature.
2015-04-14
Technical Paper
2015-01-0366
Cristian Rostiti, Stephanie Stockar, Marcello Canova
Abstract In a conventional passenger vehicle, the AC system is the largest ancillary load. This paper proposes a novel control strategy to reduce the energy consumption of the air conditioning system of a conventional passenger car. The problem of reducing the parasitic load of the AC system is first approached as a multi-objective optimization problem. Starting from a validated control-oriented model of an automotive AC system, an optimization problem is formalized to achieve the best possible fuel economy over a regulatory driving cycle, while guaranteeing the passenger comfort in terms of cabin temperature and reduce the wear of the components. To complete the formulation of the problem, a set of constraints on the pressure in the heat exchanger are defined to guarantee the safe operation of the system. The Dynamic Programming (DP), a numerical optimization technique, is then used to obtain the optimal solution in form of a control sequence over a prescribed driving cycle.
2015-04-14
Technical Paper
2015-01-0399
Alexander Jaust, Bastian Morcinkowski, Stefan Pischinger, Jens Ewald
Abstract In this work, a transport and mixing model that calculates mixing in thermodynamic phase space was derived and validated. The mixing in thermodynamic multizone space is consistent to the one in the spatially resolved physical space. The model is developed using a turbulent channel flow as simplified domain. This physical domain of a direct numerical simulation (DNS) is divided into zones based on the quantitative value of transported scalars. Fluxes between the zones are introduced to describe mixing from the transport equation of the probability density function based on the mixing process in physical space. The mixing process of further scalars can then be carried out with these fluxes instead of solving additional transport equations. The relationship between the exchange flux in phase space and the concept of scalar dissipation are shown and validated by comparison to DNS results.
2015-04-14
Technical Paper
2015-01-0442
Sudhi Uppuluri, Ajay Naiknaware
This paper discusses the sensitivity of key parameters that are used as an input into engine cooling system simulation model that affect the coolant temperature and required airflow calculations. In simulation, these parameters are obtained either from calculations of other programs such as a combustion program or from measured engine test data and are typically assumed to be constant. Tests and measurements from vehicle tests indicate that these parameters always vary affecting the final predicted coolant temperature. The sensitivity on few selected parameters such as the ambient pressure, temperature, humidity, coolant properties among others were studied. Results discussed in this paper quantify the effect of each of these parameters on required airflow and advise which parameters must be tightly controlled to improve the robustness of the simulation model and the accuracy of predictions.
2015-04-14
Journal Article
2015-01-0438
Ashley Lehman, Vesselin Stoilov, Andrzej Sobiesiak
Abstract This paper describes the application of the Fourier Amplitude Sensitivity Test (FAST) method [1] to investigate the effect of uncertainty in design parameters on the thermal system performance of vehicle underbody components. The results from this study will pinpoint the design parameters which offer the greatest opportunity for improvement of thermal system performance and reliability. In turn, this method can save engineering time and resources. An analytical model was developed for a vehicle underbody system consisting of a muffler, heat shield, and spare tire tub. The output from this model was defined as the temperature of the spare tire tub. The majority of the input parameters in this model deviate from their nominal values due to environmental factors, wear and ageing, and/or variation in the manufacturing process.
2015-04-14
Journal Article
2015-01-0671
Saeed Jahangirian, Ashutosh Srivastava, Seyed Alireza Hosseini, Steven Ballard, Naiqiang Wu, John Kiedaisch
Abstract Durability assessments of modern engines often require accurate modeling of thermal stresses in critical regions such as cylinder head firedecks under severe cyclic thermal loading conditions. A new methodology has been developed and experimentally validated in which transient temperature distributions on cylinder head, crankcase and other components are determined using a Conjugate Heat Transfer (CHT) CFD model and a thermal finite element analysis solution. In the first stage, cycle-averaged gas side boundary conditions are calculated from heat transfer modeling in a transient in-cylinder simulation. In the second stage, a steady-state CHT-CFD analysis of the full engine block is performed. Volume temperatures and surface heat transfer data are subsequently transferred to a thermal finite element model and steady state solutions are obtained which are validated against CFD and experimental results.
2015-04-14
Technical Paper
2015-01-0613
Donghong Ning, James Coyte, Hai Huang, Haiping Du, Weihua Li
Abstract This paper presents a study on experimental vibration simulation using a multiple-DOF motion platform for heavy duty vehicle seat suspension test. The platform is designed to have 6-DOF with the advantages of high force-to-weight ratio, high dexterity and high position accuracy. It can simulate vehicle vibrations in the x, y and z translational axis and in the roll pitch and yaw axis rotation. To use this platform to emulate the real vibration measured from vehicle seat base under real operation for vehicle seat suspension test in lab, an Inertial Measurement Unit (IMU) is applied to collect the acceleration data from a real vehicle. An estimation algorithm is developed to estimate the displacement from the measured acceleration. The estimated displacement is then used to calculate the length of each leg of the platform so that the platform can generate the motion similar to the measured one.
2015-04-14
Technical Paper
2015-01-1651
Francisco Payri, Jaime Martin, Antonio Garcia, Ricardo Carreño
Abstract In recent years, the spread use of after-treatment systems together with the growing awareness about the climate change is leading to an increase in the importance of the efficiency over other criteria during the design of internal combustion engines. In this sense, it has been demonstrated that performing an energy balance is a suitable methodology to assess the potential of different injection or air management strategies, to reduce consumption as well as determining the more relevant energy terms that could be improved. In this work, an experimental energy balance with the corresponding comprehensive analysis is presented. The main objective is the identification of how the energy is split, considering internal and external balances. For this purpose, some parametric studies varying the coolant temperature, the intake air temperature and the start of the injection timing have been performed. The results quantify the effect of each parametrical study on engine efficiency.
2015-04-14
Technical Paper
2015-01-1623
Ivan Arsie, Rocco Di Leo, Stefano Falco, Cesare Pianese, Matteo De Cesare
Abstract International regulations continuously restrict the standards for the exhaust emissions from automotive engines. In order to comply with these requirements, innovative control and diagnosis systems are needed. In this scenario the application of methodologies based on the in-cylinder pressure measurement finds widespread applications. Indeed, almost all engine thermodynamic variables useful for either control or diagnosis can be derived from the in-cylinder pressure. Apart for improving the control accuracy, the availability of the in-cylinder pressure signal might also allow reducing the number of existing sensors on-board, thus lowering the equipment costs and the engine wiring complexity. The paper focuses on the detection of the engine thermal state, which is fundamental to achieve suitable control of engine combustion and after-treatment devices.
2015-04-14
Technical Paper
2015-01-1609
Roberto Monforte, Francesco Lovuolo, Matteo Rostagno, Riccardo Seccardini, Teron Matton
Abstract Following the development of new technologies in Vehicle Thermal Management aiming to both enhancing the MAC System efficiency and reducing the thermal load to be managed, a prediction tool based on the AMEsim platform was developed at Advanced PD EMEA. This tool is dedicated to predict the effect of the implementation of sensors monitoring both the relative humidity and the carbon dioxide (CO2) concentration (taking into account passengers' generated moisture and CO2). This model implemented with the usual comfort inputs (CO2 and RH acceptable ranges) considers the system variables influencing the comfort and predicts the increase of both RH and CO2 concentration in the cabin compartment in any driving cycle depending on the number of occupants.
2015-04-14
Technical Paper
2015-01-1610
Xiaomeng Shen, Gangfeng Tan, Quan Zhou, Zhongjie Yang, Min Hua
Abstract The Organic Rankine Cycle System is an effective approach for recovering the engine exhaust thermal energy. The physical characteristic of the Rankine fluid is the key factor for the capacity and the stability of the expander power output. In the research, the influences of the evaporator organic medium state and flow rate on the expander power output are fully analyzed for the sufficient utilization of the waste thermal energy. Firstly, the exhaust characteristics of the diesel engine were processed by the data of the bench test. Then, the integral mathematical model of the Organic Rankine Cycle was built. Based on the comparison for the 2-zone and 3-zone evaporator, the influence for expander output are analyzed especially emphasis on the factors of engine working condition, the flow rate, temperature and state of Rankine fluid.
2015-04-14
Technical Paper
2015-01-1605
Hee Sang Park
Abstract Electric powered vehicles rely on electric heater to heat the cabin of the vehicle. These heaters consume electric energy from the battery and cause depletion of the vehicle's range by 20∼40%. In order to extend the range of electric vehicles, we need to increase the efficiency of HVAC. EV has waste heat but the heat power is much lesser than internal combustion engine and heat source is separated physically. In order to utilize waste heat to achieve better efficiency, heat collection, heat insulation, pre-heating are necessary. Based on the new concept system, we examined the effects of fuel efficiency
2015-04-14
Technical Paper
2015-01-1606
Saroj Pradhan, Arvind Thiruvengadam, Pragalath Thiruvengadam, Marc C. Besch, Daniel Carder
Heavy-duty diesel (HDD) engines are the primary propulsion source for most heavy-duty vehicle freight movement and have been equipped with an array of aftertreatment devices to comply with more stringent emissions regulations. In light of concerns about the transportation sector's influence on climate change, legislators are introducing requirements calling for significant reductions in fuel consumption and thereby, greenhouse gas (GHG) emission over the coming decades. Advanced engine concepts and technologies will be needed to boost engine efficiencies. However, increasing the engine's efficiency may result in a reduction in thermal energy of the exhaust gas, thus contributing to lower exhaust temperature, potentially affecting aftertreatment activity, and consequently rate of regulated pollutants. This study investigates the possible utilization of waste heat recovered from a HDD engine as a means to offset fuel penalty incurred during thermal management of SCR system.
2015-04-14
Technical Paper
2015-01-1607
Chuen-Sen Lin, Vamshi Avadhanula, Vamsi Mokkapati, Daisy Huang, Brent Sheets
This paper presents test results of a 50 kW Organic Rankine Cycle (ORC) system and proposed guidelines for how to effectively apply this system to the rural Alaska power industry. In rural Alaska, approximately 180 villages rely on off-grid diesel generators for power. Most of the generators have capacities of about 1 MW or less. In general, the average operation efficiencies are noticeably less than 40%, with the rest of the fuel energy becoming heat. If the heat is not applied for useful application, it is called waste heat. Most of the wasted heat is contained in engine exhaust and jacket fluid and eventually dissipates into the environment. For rural Alaska, waste heat for heating is most effective; in many cases, waste heat for power may be needed due to a variety of reasons. Many rural Alaskan villages are reluctant to apply exhaust heat recovery due to concerns about corrosion and soot accumulation in the exhaust system and their effect on emissions.
2015-04-14
Technical Paper
2015-01-1608
Davide Di Battista, Marco Mauriello, Roberto Cipollone
Abstract A smart way to reduce CO2 emission in transportation sector is to recover energy usually wasted and re-use it for engine and vehicle needs. ORC plant on exhaust gas of ICE is really interesting, but it has a significant impact on the exhaust line and vehicle's weight. The backpressure realized in the exhaust and the weight gain, in fact, produce a specific fuel consumption increase as well as an increase in the propulsion power: both terms could vanish the energy recovered. The paper discusses the effects of the pressure losses produced by an ORC plant mounted on the exhaust line of an IVECO F1C test bench engine. The interactions produced on the turbocharged engine have been experimentally investigated: the presence of an IGV turbocharger makes the effect of the backpressure not straightforward to be predicted and needed a full experimental testing of the group in order to understand its reaction and the net effect in terms of specific fuel consumption.
2015-04-14
Technical Paper
2015-01-0147
Matthew J. Pitts, Elvir Hasedžić, Lee Skrypchuk, Alex Attridge, Mark Williams
Abstract The advent of 3D displays offers Human-Machine Interface (HMI) designers and engineers new opportunities to shape the user's experience of information within the vehicle. However, the application of 3D displays to the in-vehicle environment introduces a number of new parameters that must be carefully considered in order to optimise the user experience. In addition, there is potential for 3D displays to increase driver inattention, either through diverting the driver's attention away from the road or by increasing the time taken to assimilate information. Manufacturers must therefore take great care in establishing the ‘do’s and ‘don’t's of 3D interface design for the automotive context, providing a sound basis upon which HMI designers can innovate. This paper describes the approach and findings of a three-part investigation into the use of 3D displays in the instrument cluster of a road car, the overall aim of which was to define the boundaries of the 3D HMI design space.
2015-04-14
Technical Paper
2015-01-0169
Kazuyuki Nakata, Maya Seki, Ryoichi Nishikawa, Soju Matsumoto, Shinichiro Murakami, Yukio Yoshino
Abstract Instrument clusters that display all information on a TFT-LCD screen, also known as reconfigurable instrument clusters, have become the new trend in automotive interiors. DENSO mass-produced the world's first reconfigurable instrument cluster in 2008. To satisfy customer requirements, large quantities of resources were required. Coupled with an iterative process due to requirement changes, development costs became very high. Reducing development costs was vital in order to expand the reconfigurable instrument cluster product line. A new artist-centric HMI (human machine interface) software development workflow is proposed to reduce the development effort by introducing a data converter and real-time 3D rendering engine in our earlier paper. Our goal is to realize an environment with little programming during development by utilizing a tool chain to automate the majority of the programmer's tasks.
2015-04-14
Technical Paper
2015-01-0476
Hyunkwon Jo, Youngseung Kim, Hyunchul Lee, Hyunmin Park, Suckin Song
Abstract Carmakers have tried to lower the vehicle weight for raising fuel efficiency. This trend involves a trade-off with the vehicle stiffness. In automobile interior parts, the thickness has needed to be decreased for the weight reduction but this makes the stiffness worse. A new approach for improving the stiffness due to the weight reduction is required and various optimization methods at early development stage have been introduced currently. However, it is difficult to apply optimization for the interior parts since many interior parts' structures generally depend on the design. But as studying the structure in detail, we discovered some factors that affect the performance without depending on design. The door trim is selected for optimization item because it has many characteristics of automobile interior parts. In our case study, the factors that improve the performance of door trim without changing design are considered as fastener position and flange rib layout.
2015-04-14
Technical Paper
2015-01-0505
Miguel Angel Reyes Belmonte, Colin D. Copeland, Drummond Hislop, George Hopkins, Adrian Schmieder, Scott Bredda, Sam Akehurst
Abstract Pressure and temperature levels within a modern internal combustion engine cylinder have been pushing to the limits of traditional materials and design. These operative conditions are due to the stringent emission and fuel economy standards that are forcing automotive engineers to develop engines with much higher power densities. Thus, downsized, turbocharged engines are an important technology to meet the future demands on transport efficiency. It is well known that within downsized turbocharged gasoline engines, thermal management becomes a vital issue for durability and combustion stability. In order to contribute to the understanding of engine thermal management, a conjugate heat transfer analysis of a downsized gasoline piston engine has been performed. The intent was to study the design possibilities afforded by the use of the Selective Laser Melting (SLM) additive manufacturing process.
2015-04-14
Technical Paper
2015-01-0331
Sina Shojaei, Simon Robinson, Chris Chatham, Andrew McGordon, James Marco
Abstract Among the auxiliary systems on electric and hybrid electric vehicles the electric air conditioning (eAC) system causes the largest load on the high voltage battery and can significantly impact the energy efficiency and performance of the vehicle. New methods are being investigated for effective management of air conditioning loads through their integration into vehicle level energy management strategies. For this purpose, a fully integrated vehicle model is developed for a commercially available hybrid vehicle and used to develop energy management algorithms. In this paper, details of the eAC model of this vehicle are discussed, including steady state component validation against rig data. Also results of simulating the cabin pull-down are included.
2015-04-14
Technical Paper
2015-01-0330
Iman Goldasteh, Shi-Ing Chang, Salamah Maaita, Gursaran Mathur
Abstract Proper flow distribution on the windshield and side windows is critical for adequate visibility while driving. Fog or ice which forms on the windshield is the main reason of invisibility and leads to major safety issue. It has been shown that proper clear visibility for the windshield could be obtained with a better flow pattern and uniform flow distribution in the defrost mode of the automobile heating, ventilation, and air-conditioning (HVAC) system. In this study, a three dimensional numerical model of a car cabin with full HVAC system was developed using Star-CCM+, a commercial CFD package. The Reynolds-Averaged Navier-Stokes equations (RANS) approach with the realizable two-layer k-ε turbulence model was employed for simulating the airflow field on the windshield for the defrost mode. The HVAC unit, ducts and defroster grille were included in the analysis in detail and the air distribution on the windshield was studied.
2015-04-14
Technical Paper
2015-01-0329
Mark Hepokoski, Allen Curran, Richard Burke, John Rugh, Larry Chaney, Clay Maranville
Abstract Reliable assessment of occupant thermal comfort can be difficult to obtain within automotive environments, especially under transient and asymmetric heating and cooling scenarios. Evaluation of HVAC system performance in terms of comfort commonly requires human subject testing, which may involve multiple repetitions, as well as multiple test subjects. Instrumentation (typically comprised of an array of temperature sensors) is usually only sparsely applied across the human body, significantly reducing the spatial resolution of available test data. Further, since comfort is highly subjective in nature, a single test protocol can yield a wide variation in results which can only be overcome by increasing the number of test replications and subjects. In light of these difficulties, various types of manikins are finding use in automotive testing scenarios.
2015-04-14
Technical Paper
2015-01-0328
Wilko Jansen, Joe Amodeo, Sam Wakelam, Kamalesh Bhambare
Abstract The level of infotainment in today's vehicles and the customer expectation of the functionality imply a significant effort is required on thermal management of the systems, to guarantee their full operation under all operating conditions. The worst case thermal conditions the system will get exposed to are caused by solar loading on the cabin or heat up as a result of cabin heating. Simulation of a solar load driven case will be discussed in this paper. The long soak conditions during these tests result in the modelling requirement for long natural convection periods. This is creating a challenge for the conventional CFD simulations in turnaround time. New simulation methodology has resulted in significant speed up enabling these fully transient simulations in a reasonable turnaround time to enable programme support. A two phase approach to simulating this problem is proposed in this paper.
2015-04-14
Journal Article
2015-01-0326
Takuya Yamaguchi, Yuzo Aoyagi, Noboru Uchida, Akira Fukunaga, Masayuki Kobayashi, Takayuki Adachi, Munemasa Hashimoto
Abstract In heavy duty diesel engines, the waste heat recovery has attracted much attention as one of the technologies to improve fuel economy further. In this study, the available energy of the waste heat from a high boosted 6-cylinder heavy duty diesel engine which is equipped with a high pressure loop EGR system (HPL-EGR system) and low pressure loop EGR system (LPL-EGR system) was evaluated based on the second law of thermodynamics. The maximum potential of the waste heat recovery for improvement in brake thermal efficiency and the effect of the Rankine combined cycle on fuel economy were estimated for each single-stage turbocharging system (single-stage system) and 2-stage turbocharging system (2-stage system).
2015-04-14
Technical Paper
2015-01-0351
Jason A. Lustbader, Cory Kreutzer, Steven Adelman, Skip Yeakel, John Zehme
Abstract Annual fuel use for long-haul truck rest period idling is estimated at 667 million gallons in the United States. The U.S. Department of Energy's National Renewable Energy Laboratory's CoolCab project aims to reduce heating, ventilating, and air conditioning (HVAC) loads and resulting fuel use from rest period idling by working closely with industry to design efficient long-haul truck climate control systems while maintaining occupant comfort. Enhancing the thermal performance of cab/sleepers will enable smaller, lighter, and more cost-effective idle reduction solutions. In order for candidate idle reduction technologies to be implemented at the original equipment manufacturer and fleet level, their effectiveness must be quantified. To address this need, a number of promising candidate technologies were evaluated through experimentation and modeling to determine their effectiveness in reducing rest period HVAC loads.
2015-04-14
Technical Paper
2015-01-0350
Zhi Li, Gangfeng Tan, Jing Cai, Zhongjie Yang, YiRui Wang, Haobo Xu
Abstract The vehicle engine exhaust wastes heat. For the conventional scheme, the hot-end of the thermoelectric module is connected with the exhaust pipe, while the cold-end is cooled through the vehicle engine cooling cycle. The variation of vehicle engine operating conditions brings the instability of the hot-end temperature, which affects the power generation performance of thermoelectric materials and increases the damage risk to the thermoelectric materials caused by the high temperature. This research adopts the heat transfer oil circulation as the intermediate fluid to absorb the dynamic heat flux of the vehicle engine exhaust so as to release the heat steadily to the hot-end of the thermoelectric module. The thermal characteristics of the target diesel vehicle engine exhaust gas are evaluated based on the experimental data firstly.
2015-04-14
Technical Paper
2015-01-0347
Logesh Shankar Somasundaram, S Sriraman, Rakesh Verma
The paper aims at numerically modeling the flow and thermal processes occurring in an agricultural tractor using Computational Fluid Dynamics (CFD) and determines the comfort level of the tractor operator during working condition. The motive of the investigation is to develop and demonstrate capabilities of CFD as an automotive analysis tool. The work describes a methodology that significantly stream lines the process of thermal flow taking place in a tractor by utilizing state-of-the art computer simulation of air flow and heat transfer. The numerical investigation carried out with a three-dimensional geometry of the vehicle assembly and the measurements were taken from the vehicle. The geometry created with Pro/Engineer formed the domain for the automatically generating discretized grid contained the majority of the main components within the underhood environment.
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