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Viewing 1 to 30 of 3482
2017-04-11
Journal Article
2017-01-9450
Ali Reza Taherkhani, Carl Gilkeson PhD, Philip Gaskell PhD, Rob Hewson PhD, Vassili Toropov PhD, Amin Rezaienia PhD, Harvey Thompson
Abstract This paper investigates the optimization of the aerodynamic design of a police car, BMW 5-series which is popular police force across the UK. A Bezier curve fitting approach is proposed as a tool to improve the existing design of the warning light cluster in order to reduce drag. A formal optimization technique based on Computational Fluid Dynamics (CFD) and moving least squares (MLS) is used to determine the control points for the approximated curve to cover the light-bar and streamline the shape of the roof. The results clearly show that improving the aerodynamic design of the roofs will offer an important opportunity for reducing the fuel consumption and emissions for police vehicles. The optimized police car has 30% less drag than the non-optimized counter-part.
2017-04-06
Event
Paper offers on the following topics are welcome: test facilities, unsteady aerodynamics, fuel economy, cooling airflow, fundamental aerodynamics and aerodynamics development.
2017-04-06
Event
Paper offers on the following topics are welcome: test facilities, unsteady aerodynamics, fuel economy, cooling airflow, fundamental aerodynamics and aerodynamics development.
2017-04-05
Event
Paper offers on the following topics are welcome: test facilities, unsteady aerodynamics, fuel economy, cooling airflow, fundamental aerodynamics and aerodynamics development.
2017-04-05
Event
Paper offers on the following topics are welcome: test facilities, unsteady aerodynamics, fuel economy, cooling airflow, fundamental aerodynamics and aerodynamics development.
2017-04-05
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.
2017-04-05
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.
2017-03-28
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
2017-01-0213
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
2017-01-0212
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
2017-01-1358
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
2017-01-1592
Jingdong Cai, Saurabh Kapoor, Tushita Sikder, Yuping He
In this paper, active aerodynamic wings are investigated using numerical simulation in order to improve vehicle handling performance under high-speed cornering maneuvers. Air foils are selected and analyzed to determine the basic features of aerodynamic wings. Built upon the airfoil analysis, the 3D aerodynamic wing model is developed using a commercial software package, Siemens NX®. Then the virtual aerodynamic wings are assembled with the 3D vehicle model designed also using Siemens NX®. The resulting 3-D geometry model is used for aerodynamic analysis based on numerical simulation using a computational fluid dynamics (CFD) software package, ANSYS FLUENT®. The CFD-based simulation data and the multibody dynamic vehicle model generated CarSim®are combined to study the effects of active aerodynamic wings on handling performance of high-speed vehicles.
2017-03-28
Technical Paper
2017-01-1524
Robert Lietz, Levon Larson, Peter Bachant, John Goldstein, Rafael Silveira, Mehrdad Shademan, Pete Ireland, Kyle Mooney
The number of computational fluid dynamics simulations performed during the vehicle aerodynamic development process continues to expand at a rapid rate. One key contributor to this trend is the number of analytically based designed experiments performed to support vehicle aerodynamic shape development. A second contributor is the number of aerodynamic optimization studies performed for vehicle exterior components such as mirrors, underbody shields, spoilers, etc. A third contributor is the increasing number of “what if” exploratory studies performed early in the design process when the design is relatively fluid. Licensing costs for commercial CFD solutions become a significant constraint as the number of simulations expand. A number of alternative products (independently developed, supported and documented forks of the popular OpenFOAM® toolbox) have become available in recent years offering a lower cost alternative to traditional commercial CFD products.
2017-03-28
Technical Paper
2017-01-1533
Kathleen DeMarco, James Stratton, Kevin Chinavare, Garry VanHouten
Over the next ten years, with the introduction of WLTP in Europe and increased CAFE standards in the United States, fuel economy and emissions reductions are going to play a larger role in vehicle development than ever before. Two major ways to increase fuel economy and reduce emissions are by reducing mass and increasing aerodynamics. In the wheel segment, most lightweight wheel designs are detrimental to aerodynamics and aerodynamic wheels are seen as unstylish and with a high mass penalty. One solution is through the use of composite wheel technology which replaces non-structural aluminum with lighter weight materials. This study used SAE J2263 and SAE J2264 procedures to establish baseline fuel economy numbers and to evaluate various mass, inertial and aerodynamic differences between wheel concepts. Additional physical studies included steady state testing and real world road testing.
2017-03-28
Technical Paper
2017-01-1230
Cyrille Goldstein, Joel Hetrick
Mechanical losses in electric machines can contribute significantly to overall system losses in an electric drive. With an Interior Permanent Magnet (IPM) machine, measuring mechanical losses is difficult without an un-magnetized rotor. Even with an un-magnetized rotor, physical testing can be time consuming and expensive. This paper presents a theoretical model of mechanical drag in an electric machine. The model was built using calculations for bearing, seal, and windage drag. This model was compared to experimental results and a sensitivity study was completed to understand inaccuracies in the model. Based on this information, the model was modified to better represent the physical system. The goal of this work is to understand the contributors to mechanical drag, to be able to estimate mechanical losses without physical testing, and to evaluate design choices that could reduce mechanical losses.
2017-03-28
Technical Paper
2017-01-1538
Jiaye Gan, Longxian Li, Gecheng Zha, Craig Czlapinski
This paper conducts numerical simulation and wind tunnel testing to study the passive jet boat tail(JBT) drag reduction flow control for a heavy duty truck rear view mirror. The JBT passive flow control technique is to introduce a flow jet by opening an inlet in the front of a bluff body, accelerate the jet via a converging duct and eject the jet at an angle toward the center of the base surface. The high speed jet flow entrains the free stream flow to energize the base flow, increase the base pressure, reduces the wake size, and thus reduce the drag. A baseline heavy duty truck rear view mirror is used as reference. The mirror is then redesigned to include the JBT feature without violating any of the variable mirror position geometric constraints and internal control system volume requirement. The wind tunnel testing was conducted at various flow speed and yaw angles.
2017-03-28
Technical Paper
2017-01-1540
Yuri M. Lopes, Maxwell R. Taylor, Todd H. Lounsberry, Gregory J. Fadler
Typical production vehicle testing includes testing of a vehicle towing a trailer to evaluate powertrain thermal performance. In order to correlate tests with simulations, the aerodynamic effects of pulling a trailer behind a vehicle must be estimated. Since during real world conditions a vehicle encounters crosswinds most of the time, the effects of cross winds on the drag of a vehicle–trailer combination should be taken into account. Improving the accuracy of aerodynamic forces for a vehicle-trailer combination should in turn lead to improved simulations and a better prediction of thermal performance. In order to best simulate real world conditions, a study was performed using reduced scale models of an SUV and a pickup truck towing a medium size cargo trailer. The vehicle and trailer combinations were tested in a full scale wind tunnel.
2017-03-28
Technical Paper
2017-01-1537
Ananya Bhardwaj
Improving brake cooling has commanded substantial research in the automotive sector, as safety remains paramount in vehicles of which brakes are a crucial component. To prevent problems like brake fade and brake judder, heat dissipation should be maximized from the brakes to limit increasing temperatures. This research is a CFD investigation into the impact of existing wheel center designs on brake cooling through increased cross flow through the wheel. The novel study brings together the complete wheel and disc geometries in a single CFD study and directly measures the effect on brake cooling, by implementing more accurately modelled boundary conditions like moving ground to exactly replicate true conditions. It also quantifies the improvement in cooling rate of the brake disc with change in wheel design unlike previous studies. The axial flow discharge was found to be increased to 0.47 m3/min for the suggested design in comparison to 0.04 m3/min for traditional design.
Viewing 1 to 30 of 3482

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