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Viewing 1 to 30 of 3471
2017-04-04
Event
Paper offers on the following topics are welcome: test facilities, unsteady aerodynamics, fuel economy, cooling airflow, fundamental aerodynamics and aerodynamics development.
2017-04-04
Event
The purpose of this session is to bring awareness among the automotive aerodynamics, thermal and hydraulic systems development community to address the need of reliability analysis and robust design to improve the overall product quality. This session also introduces CAE based optimization of aero-thermal and fluid systems to improve automotive fuel economy. This session presents papers covering both testing and simulation.
2017-04-04
Event
Paper offers on the following topics are welcome: test facilities, unsteady aerodynamics, fuel economy, cooling airflow, fundamental aerodynamics and aerodynamics development.
2017-04-04
Event
Paper offers on the following topics are welcome: test facilities, unsteady aerodynamics, fuel economy, cooling airflow, fundamental aerodynamics and aerodynamics development.
2017-04-04
Event
Paper offers on the following topics are welcome: test facilities, unsteady aerodynamics, fuel economy, cooling airflow, fundamental aerodynamics and aerodynamics development.
2017-04-04
Event
Paper offers on the following topics are welcome: test facilities, unsteady aerodynamics, fuel economy, cooling airflow, fundamental aerodynamics and aerodynamics development.
2017-04-04
Event
Paper offers on the following topics are welcome: test facilities, unsteady aerodynamics, fuel economy, cooling airflow, fundamental aerodynamics and aerodynamics development.
2017-04-04
Event
Paper offers on the following topics are welcome: test facilities, unsteady aerodynamics, fuel economy, cooling airflow, fundamental aerodynamics and aerodynamics development.
2017-04-04
Event
Paper offers on the following topics are welcome: test facilities, unsteady aerodynamics, fuel economy, cooling airflow, fundamental aerodynamics and aerodynamics development.
2017-04-04
Event
Paper offers on the following topics are welcome: test facilities, unsteady aerodynamics, fuel economy, cooling airflow, fundamental aerodynamics and aerodynamics development.
2017-03-28
Technical Paper
2017-01-1515
Neil Lewington, Lauri Ohra-aho, Olav Lange, Klaus Rudnik
Industry trends towards lighter, more aerodynamically efficient road vehicles has the potential to degrade a vehicle’s response to crosswinds. In this paper, a methodology is outlined that indirectly couples a computational fluid dynamics (CFD) simulation of the vehicle’s aerodynamic characteristics with a multi-body dynamics simulation (MBD) to determine yaw, roll and lateral response characteristics during a ‘severe’ crosswind event. This indirect coupling approach mimics physical test conditions outlined in open loop test method ISO 12021:2010 that forms part of the vehicle sign-off criterion at Ford Motor Company. The methodology uses an overset mesh CFD method to drive the vehicle through a prescribed crosswind event, providing unfiltered predictions of vehicle force and moment responses that are used as applied forces in the MBD model. The method does not account for changes in vehicle attitude due to applied aerodynamic forces and moments.
2017-03-28
Technical Paper
2017-01-0210
Ahmed Imtiaz Uddin, Abd El-Rahman Ali Hekal, Dipan P. Arora, Alaa El-Sharkawy, Sadek S. Rahman
With the increase in demand of fuel efficient transportation system, various efforts have been made to collect waste energies to reduce the fuel consumption and emissions in the automobiles. Currently, in a typical internal combustion engine, approximately one third of the fossil fuel combustion by-product is wasted heat. By collecting the heat emitted through the exhaust systems using heat exchanger concept can be used to increase the passenger heating and comfort during cold ambient conditions as well as reduction of exhaust system surface temperatures. Lower exhaust surface temperature improves the durability of various under-hood and underbody components near the exhaust pipe. In this paper, the effects of integrating a gas/coolant heat exchanger close to the engine catalytic converter on reduction of the exhaust surface temperature for various real-world dynamic driving conditions are presented.
2017-03-28
Technical Paper
2017-01-0215
Mohammad Nahid, Amin Sharfuzzaman, Joydip Saha, Harry Chen, Sadek S. Rahman
More stringent Federal emission regulations and fuel economy requirements have driven the automotive industry toward more sophisticated vehicle thermal management systems to best utilize the waste heat and improve driveline efficiency. The final drive unit in light and heavy duty trucks usually consists of geared transmission and differential housed in a lubricated axle. The automotive rear axles is one of the major sources of power loss in the driveline due to gear friction, churning and bearing loss and have a significant effect on overall vehicle fuel economy. These losses vary significantly with the viscosity of the lubricant. Also the temperatures of the lubricant are critical to the overall axle performance in terms of power losses, fatigue life and wear.
2017-03-28
Technical Paper
2017-01-0214
Simon o. Omekanda, Rezwanur Rahman, Eric M. Lott, Sadek S. Rahman, Daniel E. Hornback
Designing an efficient transient thermal system model has become a very important task in improving fuel economy. As opposed to steady-state thermal models, part of the difficulty in designing a transient model is optimizing a set of inputs. The first objective in this work is to develop an engine compatible physics-based 1D thermal model for fuel economy and robust control. In order to capture and study the intrinsic thermo-physical nature, both generic “Three Mass” and “Eight Mass” engine model are developed. The models have been correlated heuristically using Simulink and Flowmaster, respectively. In order to extend the lumped mass engine model it also has been extended to Simulink model. In contrast to the complexity of the models the “Heuristic search” of input parameters has been found to be challenging and time consuming.
2017-03-28
Technical Paper
2017-01-0216
Joydip Saha, Harshit Coutinho, Sadek S. Rahman
Current and future automotive systems are becoming more complex than ever. They consist of different subsystems such as the engine, transmission, cooling system, driveline, controls systems, HVAC and active/passive safety systems. Hardware and software development for each of these subsystems have different timeline’s. The subsystems are usually developed by different teams within an organization and in some cases are also developed by suppliers. These are some of the main hurdles for carrying out a system level analysis of the vehicle earlier in the development process. Model.CONNECT was used to overcome the above mentioned hurdles by connecting a driveline model, a cooling system model, thermal controller and two-phase flow models with minimal effort.
2017-03-28
Technical Paper
2017-01-0217
Alaa El-Sharkawy, Dipan P. Arora, Amr Gamal Sami, Abd El-Rahman Ali Hekal
In this paper, an algorithm for transient thermal analysis of rotating components has been developed. The analysis considers the effect of a radiation from surrounding heat sources and convection by under-body airflow. The objective of this work is to determine the instantaneous temperature of the rotating element’s surface at different operating conditions. Experimental determination of these temperatures is possible though it is typically a challenging task, especially at high rotational speeds and high temperatures. The proposed model utilizes a modular approach to calculate the view factor between the radiation heat source and the rotating component. This approach can be extended to include any geometric layout and arrangement between the two surfaces. The view factors are dynamically evaluated at each time step during the simulation process.
2017-03-28
Technical Paper
2017-01-0213
Rezwanur Rahman, Sadek S. Rahman
The demand for Hybrid Electrified Vehicles (HEVs) is increasing due to government regulations on fuel economy. The battery systems in a PHEV have achieved tremendous efficiency over past few years. The system has become more delicate and complex in architecture which requires sophisticated thermal management. Primary reason behind this is to ensure effective cooling of the cells. Hence the current work has emphasized on developing a “Physics based” thermal management modeling framework for a typical battery system. In this work the thermal energy conservation has been analyzed thoroughly in order to develop necessary governing equations for the system. Since cooling is merely a complex process in HEV battery systems, the underlying mechanics has been investigated using the current model. The framework was kept generic so that it can be applied with various architectures. In this paper the process has been standardized in this context.
2017-03-28
Technical Paper
2017-01-0211
Alaa El-Sharkawy, Avik Chakravarty
In this paper we investigate the application of time constant to estimate the convective heat transfer coefficients from experimental vehicle-level test data. For simulation of vehicle components temperatures, heat transfer coefficients are critical pieces of information that must be known with a reasonably high level of accuracy. Available data from literature are based on empirical equations that may or may not apply for the components of interest. The variation in accuracy depends on the geometry of the components being investigated and the airflow around it. In this approach, the vehicle speed is allowed to run in a step change under fixed engine load and ambient temperature. The test is allowed to continue until component temperature reaches steady state. The time constant for each component is determined from the response curve. From the time constant data, convective heat transfer coefficient can be determined.
2017-03-28
Technical Paper
2017-01-0212
Mohammad Nahid, Rezwanur Rahman, Tabassum Hossainy, Shreyas Kapatral, Prashant Modi, Joydip Saha, Sadek S. Rahman
More stringent Federal emission regulations and fuel economy requirements have driven the automotive industry toward more efficient vehicle thermal management systems to best utilize the heat produced from burning fuel and improve driveline efficiency. The greatest part of the effort is directed toward the hybridization of automotive transmission systems. The efficiency and durability of hybrid powertrain depends on the heat generation in electric motors and their interactions among each other, ambient condition, the cooling system and the transmission component configuration. These increase the complexity of motor temperature prediction as well as the computational cost of running a conjugate heat-transfer based CFD analysis. In this paper, 1-D physics based thermal model is developed which allows rapid and accurate component-wise temperature estimation of the electric motor as well as transmission lubricant temperature during both steady-state and transient driving cycles.
2017-03-28
Technical Paper
2017-01-0441
Zhenyu Wang, Mei Zhuang
A numerical study on sunroof noise reduction is carried out. One of the strategies to suppress the noise is to break down the strong vortices impinging upon the trailing edge of the sunroof into smaller eddies. In the current study, a serrated sunroof trailing edge with sinusoidal profiles of wavelengths is investigated for the buffeting noise reduction. A number of combinations of wavelengths and amplitudes of sinusoidal profiles is employed to examine the effects of trailing edge serrations on the noise reduction. A generic vehicle model is used in the study and a straight trailing edge is considered as a baseline. The results indicate that the trailing edge serration has a significant impact on the sound pressure level (SPL) in the vehicle cabin and it can reduce the SPL by up to 10~15 dB for the buffeting frequency.
2017-03-28
Technical Paper
2017-01-1358
Hyunbin Park
We present a novel rear-view side mirror constructed with an external lens and a planar mirror to improve both aerodynamics as well as blind spot of vehicles. We have designed the exterior lens with a free-form optical design technique to display the undistorted image on the planar mirror. The manufactured prototype of the mirror has the maximum protrusion length of 7.0 cm from the vehicle body with the field of view angle of 40 degrees for a passenger’s side, and of 15 degrees for a driver’s side, respectively. The proposed side mirror provides an alternative solution to replace conventional side mirrors in compliance with the FMVSS regulation of the rear-view side mirror of vehicles.
2017-03-28
Technical Paper
2017-01-1521
Levon Larson, Sudesh Woodiga, Ronald Gin, Robert Lietz
The resultant drag from airflow that enters the front grille of a ground vehicle for the purpose of component cooling (engine airflow drag) has a significant effect on total aerodynamic drag. Furthermore, engine airflow is known to be capable of influencing upstream external airflow (interference drag) and the combined effect of these phenomena is commonly referred to as cooling drag, which generally contributes up to 10% of total vehicle drag. Due to this coupled nature, cooling drag is difficult to understand as it contains influences from multiple locations around the vehicle. A good understanding of sources of cooling drag is paramount to drive vehicle design to a low cooling drag configuration. In this work, a production level Lincoln MKZ was modified so that a number of variables could be tested in both static ground and moving ground wind tunnel conditions. All tests were conducted at 80 MPH.
2017-03-28
Technical Paper
2017-01-1528
Levon Larson, Ronald Gin, Robert Lietz
Cooling Drag is a metric that measures the influence of airflow travelling through the open grille of a ground vehicle on overall vehicle drag, both internally (engine airflow) and externally (interference airflow). With the interference effects considered, a vehicles Cooling Drag can be influenced by various flow fields around the vehicle, not just the airflow directly entering or leaving the engine bay. For this reason, computational fluid dynamics (CFD) simulations are particularly difficult. With insights gained from a previously conducted set of experimental studies a CFD validation effort was undergone to understand which flow field characteristics contribute to CFD/test discrepancies. A Lattice-Boltzmann LES method was used to validate several test points and comparison using integral drag values, surface pressures, underbody velocities and cooling pack mass flows is presented herein.
Viewing 1 to 30 of 3471

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