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2015-06-15
Technical Paper
2015-01-2249
Saad Bennouna, Said Naji, Olivier Cheriaux, Solene Moreau, Boureima Ouedraogo, Jean Michel Ville
Passengers’ thermal comfort inside car cabin is mainly provided by the heating ventilation and air conditioning system (HVAC). The main part of HVAC modules is placed under the dash board. An HVAC module is a compact system composed of various elements which are subject to airflow. The interaction between airflow and these in-duct elements generates noise inside car cabin. Furthermore, the blower used to blow air inside the cabin must overcome the pressure generated by HVAC elements. Noise is created and its level is linked to flow and pressure. HVAC noise is an important issue for car makers and automotive suppliers wishing to reach passengers’ satisfaction. Furthermore thermal-engine cars are more and more silent. Also hybrid and electric car sells are expanding around the world. HVAC noise became a main issue for automotive actors. In order to reduce its HVAC noises, Valeo and partners worked to develop several methods.
2015-06-15
Technical Paper
2015-01-2273
Curtis Jones, Zhengyu Liu, James Hurd III, Suhas Venkatappa
This paper presents the methodology of predicting vehicle level automotive air-handling system air-rush noise sound quality (SQ) using the sub-system level measurement. Measurement setup in both vehicle level and sub-system levels are described. To assess the air-rush noise SQ, both 1/3 octave band sound pressure level (SPL) and overall Zwicker's loudness are used. The "Sound Quality Transfer Functions (SQTF)" between sub-system level and vehicle level are developed for the specified climate control modes and vehicle segment defined by J.D. Power & Associates, while the Zwicker's loudness is calculated using the un-weighted predicted 1/3 octave band SPLs by the Matlab-based program. The predicting models are demonstrated in a fairly good agreement with the measured data. The methodology is applied to the development of sub-system SQ requirement for upfront delivery of the optimum design to meet global customer satisfaction.
2015-06-15
Technical Paper
2015-01-2276
Zhengyu Liu, Donald Wozniak, Manfred Koberstein, Curtis Jones, Jan Xu, Suhas Venkatappa
Refrigerant flow-induced gurgling noise is perceived in automotive refrigerant systems which equipped with variable displacement compressors. In this study, the condition of the gurgling generation is investigated in vehicle level and the fundamental root cause is identified as the two-phase refrigerant flow entering the TXV. By conducting literature review, the acoustic characteristics of the flow patterns and the parameters affecting the flow regimes in horizontal and vertical tubes are summarized, and then the gurgling mechanism is explained as that the intermittent flow is developed at the evaporator inlet. In the end, the improved and feasible design for avoiding the intermittent flow (slug, plug or churn flow) or minimizing its formation is proposed and verified in refrigerant sub-system (RSS) level. Finally, the guidelines for the attenuation and suppression of the gurgle are provided.
2015-06-15
Technical Paper
2015-01-2275
Manfred Koberstein, Zhengyu Liu, Curtis Jones, Suhas Venkatappa
In the thermal expansion valve (TXV) refrigerant system, transient high-pitched whistle at 6.18 kHz is often perceived following air-conditioning (A/C) compressor engagements when driving at higher vehicle speed or during vehicle acceleration, especially when system equipped with the high-efficiency compressor or variable displacement compressor. The objectives of this paper are to conduct the noise source identification, investigate the key factors affecting the whistle excitation, and understand the mechanism of the whistle generation. The mechanism is hypothesized that the whistle is generated from the flow/acoustic excitation of the turbulent flow past the shallow cavity, reinforced by the acoustic/structural coupling between the tube structural and the transverse acoustic modes, and then transmitted to evaporator. To verify the mechanism, the transverse acoustic mode frequency is calculated and it is coincided to the one from measurement.
2015-05-01
Journal Article
2015-01-9017
Johannes Wurm, Matthias Fitl, Michael Gumpesberger, Esa Väisänen, Christoph Hochenauer
Abstract Nowadays, investigating underhood airflow by using numerical simulation is a standard task in the development process of passenger cars and commercial vehicles. Numerous publications exist which deal with simulating the airflow through the engine compartment of road vehicles. However, hardly anything can be found which deals with off-road vehicles and nothing exists which focuses on snowmobiles. In the presented paper the airflow and the thermal conditions inside the engine compartment of a snowmobile are investigated by the usage of computational fluid dynamics (CFD) as well as experimental methods. Field tests at arctic conditions have been conducted on a serial snowmobile to measure temperatures inside the compartment and to gain realistic boundary conditions for the numerical simulation. Thermocouples (type K) were attached under the hood to measure exhaust, air, coolant and surface temperatures of several components at previously defined load cases.
2015-04-23
WIP Standard
J3096
This SAE Recommended Practice is being developed primarily for passenger car and truck application, but may be used in marine, industrial, and similar applications.
2015-04-21
Standard
J51_201504
This SAE Standard covers reinforced hose, or hose assemblies, intended for conducting liquid and gaseous dichlorodifluoromethane (refrigerant 12) in automotive air-conditioning systems. The hose shall be designed to minimize permeation of refrigerant 12 and contamination of the system and to be serviceable over a temperature range of -30 to 120 °C (-22 to 248 °F). Specific construction details are to be agreed upon between user and supplier. NOTE— SAE J2064 is the Standard for refrigerant 134a hose. For refrigerant 134a use, refer to SAE J2064
2015-04-14
Collection
Climate control is a defining vehicle attribute and is associated with brand image. Thermal performance and quality of climate control are both critical to customer satisfaction. The system has strong design interaction with other vehicle systems, while its primary objective is to deliver thermal comfort and occupant safety with low energy consumption. Localized Comfort, Secondary Fluids, Air Quality, Controls, System Sizing and HVAC consumer interface are just a few of the recent advances.
2015-04-14
Collection
This technical paper collection focuses on state of the art simulation technologies for modeling thermal systems and their application in the development and optimization of vehicle thermal management and fuel economy. The papers in this collection will range from empirical, 1D modeling methods to three dimensional CFD models as well as coupled methods.
2015-04-14
Collection
Proper thermal management can significantly contribute to overall system energy efficiency. This technical paper collection highlights the latest developments in thermal management energy efficiency.
2015-04-14
Collection
This technical paper collection considers modeling (zero-D, 1D, 2D, 3D CFD) and experimental papers on: combustion chamber, systems (lubrication, cooling, fuel, EGR); components (oil pumps, coolant pump, fuel injectors, compressors, turbines, turbochargers, torque converters, gear box, fans, bearings, valves, ports, manifolds, turbine housing); heat exchangers (radiators, oil coolers); aftertreatment (SCR, DOC, DOF, exhaust gas cooling); battery cooling (HEV, EV, motor/generator) and controls (passive and active).
2015-04-14
Technical Paper
2015-01-1189
Satyam Panchal, Scott Mathewson, Roydon Fraser, Richard Culham, Michael Fowler
Abstract A major challenge in the development of the next generation electric and hybrid electric vehicle (EV and HEV) technology is the control and management of heat generation and operating temperatures. Vehicle performance, reliability and ultimately consumer market adoption are integrally dependent on successful battery thermal management designs. In addition to this, crucial to thermal modeling is accurate thermo-physical property input. Therefore, to design a thermal management system and for thermal modeling, a designer must study the thermal characteristics of batteries. This work presents a purely experimental thermal characterization of thermo-physical properties of a lithium-ion battery utilizing a promising electrode material, LiFePO4, in a prismatic pouch configuration. In this research, the thermal resistance and corresponding thermal conductivity of prismatic battery materials is evaluated.
2015-04-14
Journal Article
2015-01-1184
Satyam Panchal, Scott Mathewson, Roydon Fraser, Richard Culham, Michael Fowler
Abstract The performance, life cycle cost, and safety of electric and hybrid electric vehicles (EVs and HEVs) depend strongly on their energy storage system. Advanced batteries such as lithium-ion (Li-ion) polymer batteries are quite viable options for storing energy in EVs and HEVs. In addition, thermal management is essential for achieving the desired performance and life cycle from a particular battery. Therefore, to design a thermal management system, a designer must study the thermal characteristics of batteries. The thermal characteristics that are needed include the surface temperature distribution, heat flux, and the heat generation from batteries under various charge/discharge profiles. Therefore, in the first part of the research, surface temperature distribution from a lithium-ion pouch cell (20Ah capacity) is studied under different discharge rates of 1C, 2C, 3C, and 4C.
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
2015-01-0505
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
Journal Article
2015-01-1379
Hideki Matsumura, Shinichiro Itoh, Kenichi Ando
Abstract Lithium-ion cells are being used in an increasing number of electric and hybrid vehicles. Both of these vehicle types contain many cells. Despite various safety measures, however, there are still reports of accidents involving abnormal heat, smoke, and fire caused by thermal runaway in the cells. If thermal runaway in one cell triggers that of another and thus causes thermal runaway propagation, this can lead to rupture of the battery pack, car fire, or other serious accidents. This study is aimed to ensure the safety of vehicles with lithium-ion cells by clarifying such accident risks, and so we investigated the process of thermal runaway propagation. In the experiment, we created a battery module made of seven laminate-type cells tightly stacked one on another. Then, we induced thermal runaway in one of the cells, measured the surface temperatures of the cells, and collected video data as the process developed. As a result, all of the seven cells underwent thermal runaway.
2015-04-14
Technical Paper
2015-01-1230
Ahmed Imtiaz Uddin, Jerry Ku
Abstract It is well known that thermal management is a key factor in design and performance analysis of Lithium-ion (Li-ion) battery, which is widely adopted for hybrid and electric vehicles. In this paper, an air cooled battery thermal management system design has been proposed and analyzed for mild hybrid vehicle application. Computational Fluid Dynamics (CFD) analysis was performed using CD-adapco's STAR-CCM+ solver and Battery Simulation Module (BMS) application to predict the temperature distribution within a module comprised of twelve 40Ah Superior Lithium Polymer Battery (SLPB) cells connected in series. The cells are cooled by air through aluminum cooling plate sandwiched in-between every pair of cells. The cooling plate has extended the cooling surface area exposed to cooling air flow. Cell level electrical and thermal simulation results were validated against experimental measurements.
2015-04-14
Technical Paper
2015-01-1279
Pengfei Lu, Chris Brace, Bo Hu
Abstract After years of study and improvement, turbochargers in passenger cars now generally have very high efficiency. This is advantageous, but on the other hand, due to their high efficiency, only a small portion of the exhaust energy is needed for compressing the intake air, which means further utilization of waste heat is restricted. From this point of view, a turbo-compounding arrangement has significant advantage over a turbocharger in converting exhaust energy as it is immune to the upper power demand limit of the compressor. However, with the power turbine being located in series with the main turbine, power losses are incurred due to the higher back pressure which increases the pumping losses. This paper evaluates the effectiveness that the turbo-compounding arrangement has on a 2.0 litres gasoline engine and seeks to draw a conclusion on whether the produced power is sufficient to offset the increased pumping work.
2015-04-14
Journal Article
2015-01-1391
Scott Allen Ziolek, Joshua Pryor, Tony Schwenn, Adam Steinman
Abstract Optimizing climate seat systems requires increased complexity in seat design which in turn is driving a need for more detailed thermal simulation methods. This paper presents the model development considerations and results of a thermal simulation study aimed at improving the thermal seat comfort experience of Hyundai-Kia's heated seating systems.
2015-04-14
Technical Paper
2015-01-1694
Jun Li, Predrag Hrnjak
Abstract This paper presents results of the visualization of the separation in the vertical header of the automotive condenser. A prototype of a heat exchanger was made that has inlet in the middle of the header, with 21 microchannel tubes as the first pass. In the second header liquid separates and leaves through 4 microchannel tubes beneath while mostly vapor leaves through 11 microchannel tubes on the top as another exit. That way the 2nd pass has liquid below first pass and vapor above it. R134a was used in the tests. Mass flow at the inlet to the header was in the range 8.4 - 30 g/s (mass flux of 54 kg/m2·s-193 kg/m2·s) and quality at the inlet to second header was varied over a range of 0.05 to 0.25, to see their impact on the separation of two-phase flow inside the transparent header. Visualization was performed to better understand and define the physical parameters that dominate the separation phenomena.
2015-04-14
Journal Article
2015-01-1695
Satoki Tada, Takahiro Nagai, Naoki Shioda, Hirofumi Fujiu, Shunji Kumagai, Hideaki Abe, Yukihiro Isoda, Yoshikazu Shinohara
Abstract As an appropriate material for automotive thermoelectric generators, which directly convert waste heat of exhaust gas into electricity, we have developed Mg2(Si1-xSnx) thermoelectric materials with high thermoelectric performance. The performance is evaluated with the dimensionless figure of merit (ZT), and the ZT has been improved through the development of the fabrication process and the investigation of the optimum composition and dopant element. A novel liquid-solid reaction synthesis method incorporating hotpressing for the sample fabrication was effective in reducing the thermal conductivity. The n-type Mg2(Si0.50Sn0.50) doped with Sb attained a high ZT of 1.1 at 620 K. The p-type Mg2(Si0.25Sn0.75) doped with Li and Ag simultaneously achieved a ZT of 0.3 at 600 K. The effective maximum power of n-type thermoelectric element and that of p-type were calculated with the thermoelectromotive force and the mean resistivity.
2015-04-14
Technical Paper
2015-01-1692
Walter Ferraris, Fausto Di Sciullo, Carloandrea Malvicino, Francesco Vestrelli, Fabrizio Beltramelli, Giancarlo Gotta
Abstract Automotive world is rapidly changing driven by the CO2 emission regulations [1], [2] worldwide asking for a dramatic fuel consumption reduction. The on board thermal management has a relevant role influencing the front vehicle design and sizing to assure the right heat rejection capacity and being crucial to guarantee the on board system efficiency and reliability. In this context the dual level cooling system with water cooled charge air cooling is a clear trend leading to a new generation of systems [3, 4]. This paper describes a compact solution to effectively implement a dual cooling loop system with water cooled charge air cooler and water cooled condenser on small/subcompact cars giving the opportunity to integrate additional modules (e.g. in case of hybrid powertrain) to the secondary loop.
2015-04-14
Technical Paper
2015-01-1708
Tibor Kiss, Jason Lustbader, Daniel Leighton
Abstract Electric vehicles (EVs) need highly optimized thermal management systems to improve range. Climate control can reduce vehicle efficiency and range by more than 50%. Due to the relative shortage of waste heat, heating the passenger cabin in EVs is difficult. Cabin cooling can take a high portion of the energy available in the battery. Compared to internal combustion engine-driven vehicles, different heating methods and more efficient cooling methods are needed, which can make EV thermal management systems more complex. More complex systems typically allow various alternative modes of operation that can be selected based on driving and ambient conditions. A good system simulation tool can greatly reduce the time and expense for developing these complex systems. A simulation model should also be able to efficiently co-simulate with vehicle simulation programs, and should be applicable for evaluating various control algorithms.
2015-04-14
Journal Article
2015-01-1709
Daniel Leighton
Abstract Electric drive vehicles (EDVs) have complex thermal management requirements not present in conventional vehicles. In addition to cabin conditioning, the energy storage system (ESS) and power electronics and electric motor (PEEM) subsystems also require thermal management. Many current-generation EDVs utilize separate cooling systems, adding both weight and volume, and lack abundant waste heat from an engine for cabin heating. Some use battery energy to heat the cabin via electrical resistance heating, which can result in vehicle range reductions of 50% under cold ambient conditions. These thermal challenges present an opportunity for integrated vehicle thermal management technologies that reduce weight and volume and increase cabin heating efficiency. Bench testing was conducted to evaluate a combined fluid loop technology that unifies the cabin air-conditioning and heating, ESS thermal management, and PEEM cooling into a single liquid coolant-based system.
2015-04-14
Technical Paper
2015-01-1711
Christian Hainzlmaier, Alejandro S. Regueiro, Marvin Lappe
Abstract Hybrid and Electric Vehicles have a heat deficit due to frequent operation of the engine in high efficiency regions or during pure electric driving where the engine as a heat source is not available. Especially for the conditioning of the cabin, additional heat sources are necessary to ensure comfort & safety. In order to maximize the electric driving range, and improve fuel efficiency, it is important to combine a fast, efficient and safe generation of heat, with a minimum drain from the traction battery. Webasto went about this challenge and developed the new High Voltage Heater (HVH) based on a new and patented heat layer technology. This paper explains the design concept and results of the novel clean sheet research and development approach taken to achieve the project goals.
2015-04-14
Technical Paper
2015-01-1710
Xinran Tao, Kan Zhou, Andrej Ivanco, John R. Wagner, Heath Hofmann, Zoran Filipi
Abstract The components in a hybrid electric vehicle (HEV) powertrain include the battery pack, an internal combustion engine, and the electric machines such as motors and possibly a generator. These components generate a considerable amount of heat during driving cycles. A robust thermal management system with advanced controller, designed for temperature tracking, is required for vehicle safety and energy efficiency. In this study, a hybridized mid-size truck for military application is investigated. The paper examines the integration of advanced control algorithms to the cooling system featuring an electric-mechanical compressor, coolant pump and radiator fans. Mathematical models are developed to numerically describe the thermal behavior of these powertrain elements. A series of controllers are designed to effectively manage the battery pack, electric motors, and the internal combustion engine temperatures.
2015-04-14
Technical Paper
2015-01-1713
Manfred Klaus Kirschning, Frank Reußwig
Abstract Different heat shielding unilayer materials already in practical use and multilayer materials, consisting of a compound of E-glass fabric laminated with aluminum foil and different high temperature felts, are compared with regards to the difference between the external and internal surface temperature ΔT as a function of the external surface temperature. Beside that the general difference between the two standard methods convection heat measurement and radiant heat measurement is shown. Especially it is evaluated whether the radiant heat measurement method is suitable to make a general statement for classification of heat shielding materials.
2015-04-14
Technical Paper
2015-01-1712
Ram Vijayagopal, Aymeric Rousseau
Abstract Thermoelectric generators (TEGs) can be used for a variety of applications in automobiles. There is a lot of interest in using them for waste heat recovery from a fuel economy point of view. This paper examines the potential of TEGs to provide cost-effective improvements in the fuel economy of conventional vehicles and hybrid electric vehicles (HEVs). Simulation analysis is used to quantify fuel economy benefits. The paper explains how a TEG is used in a vehicle and explores the idea of improving the TEG design by introducing a thermal reservoir in the TEG model to improve the waste heat recovery. An effort is made to identify the technological and economic barriers (and their thresholds) that could prevent TEGs from becoming an acceptable means of waste heat recovery in automobiles.
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
2015-01-1610
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.
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