Display:

Results

Viewing 1 to 30 of 1072
2015-04-14
Technical Paper
2015-01-1689
Xu Song, Ryan Fortier, Scott Sarnia
The underhood hot air recirculation greatly impacts A/C system performance at idle and low vehicle speed conditions. The hot air recirculation can raise condenser cooling airflow temperature over ambient by 18°C, which lowers condenser cooling capacity and increases compressor work. Underhood airflow research suggests that a properly designed air duct is able to minimize hot air recirculation and improve the Compressors Coefficient of Performance (COP) at idle by 27%. This paper discusses underhood hot air recirculation testing methods, airflow distribution, and air duct design concepts. This dedicated air duct design indicates it should improve A/C emissions, which could contribute to meeting the Environmental Protection Agency’s (EPA) Green House Gas Emissions Regulations in North America.
2015-04-14
Technical Paper
2015-01-1692
Walter Ferraris, Fausto Di Sciullo, Carloandrea Malvicino, Francesco Vestrelli, Fabrizio Beltramelli, Giancarlo Gotta
Automotive world is rapidly changing driven by the incoming CO2 emission regulation and the need of decreased fuel consumption for every vehicle line. The introduction of high efficiency solutions in order to get fuel consumption reduction has been already done on many vehicle systems without forgetting the cost sustainability of such solutions and with a general trend of weight reduction. For what concerns cooling systems, the increased adoption of dual level cooling loops and water cooled charge air cooling is a clear trend. The present paper proposes a compact and cost effective solution with low temperature loop cooling water cooled charge air cooler and water cooled condenser for A and B segment vehicle, with the possibility to add other exchangers to the secondary loop. All the thermal load is managed by only one radiator.
2015-04-14
Technical Paper
2015-01-1611
Wei Liu
When the hydraulic retarder is working in the heavy-duty vehicle, almost all the braking power is transformed into the thermal energy of the transmission oil. The spare heat removal capacity of engine’s cooling system could be taken full advantage for cooling the retarder. However, the relative long distance of the engine and the retarder increases the risky leakage of the cooling circuit. Furthermore, the development trend of heavy load and high speed vehicle directs the significant increase in the thermal load of the hydraulic retarder, which even higher than the engine power. Conventional engine cooling system could not meet the demand of the hydraulic retarder heat rejection within the same installation space. In this research, independent two-phase evaporator was adopted to strengthen the coolant heat absorption capacity from the transmission fluid at the oil outlet of the retarder by means of the vacuum flow boiling heat transfer.
2015-04-14
Technical Paper
2015-01-1612
Wei Liu
The hydraulic retarder is a significant auxiliary braking device for the heavy duty vehicle. Traditionally, cooling circulation of the hydraulic retarder was coupled with the engine cooling system, and the thermal energy of the transmission oil would be cooled by the engine radiator ultimately. For this scheme, radiator’s spare heat removal capacity could be fully utilized whereas the cooling system is very complicated and is hard to maintain. Furthermore, the corresponding of thermal management system lags behind the power change of the retarder. In this research, integrated cooling evaporation system is developed for the hydraulic retarder, which makes the cooling water contact with the transmission oil through the wall of the fixed wheel so that it can rapidly response to the thermal variation of the retarder, keep the stability of the oil temperature and meanwhile reduce the risk of cooling medium leakage.
2015-04-14
Technical Paper
2015-01-1693
Mark Allen, Graham Hargrave, Petros Efthymiou, Viv Page, Jean-Yves Tillier, Chris Holt
It is well known that gases enter the coolant flow in internal combustion engines, and must be removed from the flow to retain cooling performance, while retaining a volume of gas in the header tank for thermal expansion and pressure control. The main gases present are air remaining from filling of the system, exhaust emissions from leakage across the head gasket, and also coolant vapour. These gases reduce the performance of the coolant pump, eventually stalling it, and also reduce the heat transfer coefficient of the fluid. This is due to the reduction in the mass fraction of liquid coolant, and the change in fluid turbulence. The aim of the project undertaken for this paper was to provide understanding of the features that are important in the design of an efficient phase separator. This study analysed several commercially available phase separators of the ‘swirl pot’ type to provide benchmarking of their gas extraction efficiency.
2015-04-14
Technical Paper
2015-01-1157
Namwook Kim, Jongryeol JEONG, Aymeric Rousseau, Henning Lohse-Busch
Argonne has analyzed control behaviors of advanced vehicles such as Hybrid Electric Vehicles (HEVs), Plug-in Hybrid Electric Vehicles (PHEVs), and Battery Electric Vehicles (BEVs) to develop simulation models and reproduce vehicle performances with simulation technique. Many of novel studies about transportation technologies conducted at Argonne utilize the simulation techniques, so well validated models are really necessary to conduct and support the advanced studies. In order to improve the research ability, Argonne has built a new testing facility, which is able to test vehicles under different thermal conditions such as -7C or 35C and has analyzed controls and performances of several advanced vehicles under the different thermal conditions. Further, the analyzed results were used to develop thermal component models that reproduce the thermal behaviors of the vehicles.
2015-04-14
Technical Paper
2015-01-0607
Xincheng Liang, Jingshan Zhao
This paper proposes a theoretical model to interpret the heat generation mechanism and thermal failure of shock absorber. For a common structure of double-tube shock absorber, all frictions between two contacting components of shock absorber are calculated particularly. The heat generation mechanism and heat distribution can be explained with the theoretical model. Thermal failure is a recurrent malfunction for traditional shock absorber, which leads to shorten the service lives of vehicle components. Heat generation experiments are accomplished to validate the thermal degeneration of shock absorber. So this study is meaningful to develop a new system of vibration attenuation that is essential to improve the riding comfort and handling stability of vehicles.
2015-04-14
Technical Paper
2015-01-1694
Jun Li, Predrag Hrnjak
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 and R1234yf are used in the tests. Mass flow was in the range 30 - 80 g/s (mass flux 170 kg/m2·s to 450 kg/m2·s) and quality at the inlet to second header over a range of 0.1 to 0.3, to see their impact on the separation of two-phase flow inside the transparent header. Visualization data were taken to better understand and define the physical parameters that dominate the separation phenomena.
2015-01-14
Technical Paper
2015-26-0192
Sourabh Shrivastava, Padmesh Mandloi
Abstract CFD simulations of an engine cooling system needs to resolve two aspects of the system; in-cylinder combustion and engine cooling. Underlying physics of an in-cylinder combustion process and heat transfer through engine cooling system requires very different time scales for resolution. This puts a limitation on practicality of solving the two problems simultaneously for any industrial case. Instead of solving the problem simultaneously, solution for an engine cooling system operating at a constant load can be derived using the coupled approach. This involves running two different CFD simulations: a transient in-cylinder simulation to model combustion in the engine, and a steady state CHT simulation using engine cooling system for heat transfer. These simulations are thermally coupled through boundary conditions and are performed in cyclic manner one after the other. Simulations are continued till the change in temperature with coupled cycles becomes insignificant.
2014-10-13
Technical Paper
2014-01-2559
Christopher Bannister
Abstract When evaluating the performance of new boosting hardware, it is a challenge to isolate the heat transfer effects inherent within measured turbine and compressor efficiencies. This work documents the construction of a lumped mass turbocharger model in the MatLab Simulink environment capable of predicting turbine and compressor metal and gas outlet temperatures based on measured or simulated inlet conditions. A production turbocharger from a representative 2.2L common rail diesel engine was instrumented to enable accurate gas and wall temperature measurements to be recorded under a variety of engine operating conditions. Initially steady-state testing was undertaken across the engine speed and load range in order that empirical Reynolds-Nusselt heat transfer relationships could be derived and incorporated into the model. Steady state model predictions were validated against further experimental data.
2014-10-13
Journal Article
2014-01-2713
Jianyi Tian, Hongming Xu, Ramadhas Arumugam Sakunthalai, Dai Liu, Cheng Tan, Akbar Ghafourian
Abstract Engine transient operation has attracted a lot of attention from researchers due to its high frequency of occurrence during daily vehicle operation. More emissions are expected compared to steady state operating conditions as a result of the turbo-lag problem. Ambient temperature has significant influences on engine transients especially at engine start. The effects of ambient temperature on engine-out emissions under the New European Driving Cycle (NEDC) are investigated in this study. The transient engine scenarios were carried out on a modern 3.0 L, V6 turbocharged common rail diesel engine fuelled with winter diesel in a cold cell within the different ambient temperature ranging between +20 °C and −7 °C. The engine with fuel, coolant, combustion air and lubricating oil were soaked and maintained at the desired test temperatures during the transient scenarios.
2014-09-28
Technical Paper
2014-01-2501
Abdulwahab A. Alnaqi, Suman Shrestha, David C. Barton, Peter C. Brooks
Abstract Aluminium alloys have been used extensively in the automotive industry to reduce the weight of a vehicle and improve fuel consumption which in turn leads to a reduction in engine emissions. The main aim of the current study is to replace the conventional cast iron rotor material with a lightweight alternative such as coated aluminium alloy. The main challenge has been to meet both the cost and functional demands of modern mass-produced automotive braking systems. A sensitivity analysis based on the Taguchi approach was carried out to investigate the effect of various parameters on the thermal performance of a typical candidate disc brake. Wrought aluminium disc brake rotors coated with alumina on the rubbing surfaces were determined to have the best potential for replacing the conventional cast iron rotor at reasonable cost. Optimisation of the structure was subsequently carried out using a genetic algorithm on the selected coated aluminium disc brake rotor.
2014-09-28
Journal Article
2014-01-2497
Bongkeun Choi
Abstract In this paper an effective technology of virtual thermal test of disc brake with several advanced analytic techniques was presented. With the virtual thermal test process, thermal performance of brake system could be easily evaluated without any possibility of great errors that used to happen in the past. In addition to the classical result of CFD, this virtual thermal test produced several valuable applications such as thermal deformation of rotor, optimization of thermal performance and estimation of braking distance.
2014-05-23
WIP Standard
J2020
This test method specifies the operating conditions for a fluorescent ultraviolet (UV) and condensation apparatus used for the accelerated exposure of various automotive exterior components. Specimen preparation, test duration, and performance evaluation procedures are addressed by each automotive manufacturerÕs material specifications. This SAE Standard may involve hazardous materials, operations, and equipment. This document does not purport to address all of the safety problems associated with its use. It is the responsibility of whoever uses this document to consult and establish appropriate and health practices and determine the applicability of regulatory limitations prior to use. Significance and Use This test method is designed to simulate extreme environmental conditions encountered on the outside of an automobile due to sunlight, heat, and to provide an acceleration of exposure for the purpose of predicting the performance of exterior automotive materials.
2014-04-01
Collection
This technical paper collection focusses 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 included will range from empirical, 1D modeling methods to three dimensional CFD models as well as coupled methods.
2013-11-13
Standard
J951_201311
The purpose of this SAE Information Report is to compare the results of Florida exposure at 45 deg from the horizontal, facing south, with those at deg from the horizontal, facing south, using various types and colors of automotive finishes.
2013-09-17
Journal Article
2013-01-2132
Jeffrey Morgan
Since the 1960's, lightning protection of aircraft has been an important design aspect, a concern for the flying public, aircraft manufacturers and the Federal Aviation Administration (FAA). With the implementation of major aircraft structures fabricated from carbon fiber reinforced plastic (CFRP) materials, lightning protection has become a more complicated issue to solve. One widely used material for lightning strike protection of CFRP structures within the aerospace industry is expanded metal foil (EMF). EMF is currently used in both military and commercial passenger aircraft. An issue that has historically been an area of concern with EMF is micro cracking of paint on the composite structure which can result in corrosion of the metal foil and subsequent loss of conductivity. This paper addresses the issues of stress and displacement in the composite structure layup which contribute to paint cracking caused by aircraft thermal cycling.
2012-11-19
Standard
J2212_201211
This SAE Recommended Practice specifies the operating procedures for a controlled irradiance, air-cooled xenon-arc apparatus used for the accelerated exposure of various automotive interior trim components. Test durations, as well as any exceptions to the sample preparation and performance evaluation procedures contained in this document, are covered in material specifications of the different automotive manufacturers.
2012-11-19
Standard
J2019_201211
This SAE Standard specifies the operating procedures for a controlled irradiance, air-cooled xenon-arc apparatus used for the accelerated exposure of various automotive exterior materials. The sample preparation, test durations, and performance evaluation procedures are covered in material specifications of the different automotive manufacturers.
2012-10-02
Technical Paper
2012-36-0304
Vinicius Durazzo Negrisolo, Ayres P. Andrade Filho, Edson Nascimento, Jose Marcelo Moura Silva, Edgard Ferraz
As part of any water pump development for engine cooling system, the interaction between materials with different coefficient of thermal expansion is unexceptional. Though in very specific applications where the coolant temperature is over 115°C several factors and variables can cause movement between parts because of the interference and coefficient of thermal expansion interaction combined with engine vibration and external loads. These factors were listed and evaluated considering several variables being validated physically and by simulation resulting on an optimized method to enhance this kind of fixation.
2012-09-10
Technical Paper
2012-01-1759
Zhelin Dong, Guohua Chen, Yankun Jiang, Chunfa Wang
A transient gas-solid heat transfer model for the 3-D (three-dimensional) coupling components in internal combustion chamber was built. In order to implement this model, a transient heat transfer program based on FEM (finite-element method) was developed, the KIVA3V code was improved, and a KIVA-FEM interface program was developed. A special treatment for the grid generation were designed and utilized. The 3-D transient non-uniform gas temperature field and convective heat transfer coefficient distribution near the combustion chamber wall can be obtained using this heat transfer model. In addition, both steady and transient temperature fields of the 3-D coupling component system of a gasoline engine were calculated and analyzed. The results show that the temporal and spatial non-uniformity of thermal boundary conditions has an important influence on the steady temperature field, transient temperature field and heat flux of the combustion chamber wall.
2012-09-10
Journal Article
2012-01-1760
Juan Du
This paper presents a method of calculating temperature field of the piston by using a wavelet neural network (WNN) to identify the unknown boundary conditions. Because of the complexity of the heat transfer and limitations of experimental conditions of heat transfer analysis of the piston in a diesel engine, boundary conditions of the piston temperature field were usually obtained empirically, and thus the result itself was uncertain. By employing the capability of resolution analysis from a wavelet neural network, the method obtains improved boundary heat transfer coefficients with a limited number of measured temperatures. Using FEA software iteratively, results show the proposed wavelet neural network analysis method improves the prediction of unknown boundary conditions and temperature distribution consistent with the experimental data with an acceptable error.
2011-12-06
Standard
J1310_201112
The scope of this SAE Information Report is to acquaint and inform those concerned with cold weather operation of diesel-powered machines and vehicles with the selection and application of electrically powered starting aids currently available. It deals specifically with the design, function, and application of line voltage electrically powered engine preheaters and battery warmers.
2011-12-06
Standard
J226_201112
This SAE Standard describes electric immersion engine preheaters for use in the coolant jacket of heavy-duty and intermediate size diesel engines. This document gives the dimensional information of the four basic styles of engine preheaters. The tables for each style will list the wattage commonly used. Small engines that typically require less than 600 W of preheat for cold weather starter are not covered by this document. These types of engines generally have very little space available to accommodate an immersion heater of the styles presented in this document. The purpose of this document is to establish commonality of engine preheater designs. The user of this document can use these current styles and wattages early on in their designing. This will give the user of this document a good engine preheater design.
2011-11-30
Standard
J1350_201111
This information report covers fuel fired pre-heaters which burn gasoline, diesel, or propane fuels. This type of heater must be used in remote areas where 110/220 V, 60 Hz electric power is not available, and is recommended anywhere an on-board self-contained system is required. The guidelines in this report are applicable, but not limited to, fuel burning heater installations on the off-road self-propelled work machine described in SAE Recommended Practice J1116.
2011-11-30
Standard
J1024_201111
This standard covers off-road, self-propelled work machines as categorized in SAE J1116. This standard outlines requirements that must be met in order for the heating equipment to perform satisfactorily on construction and industrial machinery. This standard describes a general set of parameters covering fuel-fired heaters for heating and defrosting cabs on construction and industrial machinery.
Viewing 1 to 30 of 1072

Filter