Analysis And Optimization On Aerodynamic Characteristics Of A Sport Utility Vehicle Based On CFD

With the improvement of living standards of our people and the auto industry, carsis more and more spread to people’s lives, because of SUV’s own good sportyperformance, general performance, comfort performance, it is received by people of allages and rapidly entering the high growth period. Automotive aerodynamiccharacteristic has a very important influence on the dynamic characteristics, fueleconomy and driving stability. The performance of Aerodynamic characteristics of theexternal field of the vehicle, also including underhood thermal management system arehaving an increasing influence on fuel economy reliability, comfort, and emissionperformance, so its in-depth research has become one of the key and hardy problemsfor field of Computational Fluid Dynamics.With the computer technology and the development of turbulence model,Computational Fluid Dynamics (Computational Fluid Dynamic, referred to as CFD) ismore and more applied to the vehicle development process, this paper is based on CFDtechnology to carry out research. Aerodynamics, especially the time of starting in basicresearch for the investigation on underhood thermal management is very late, andresearch on key technique of aerodynamics is lack of in-depth study, which has nowbecome one the main technical bottlenecks on CHINA’s vehicle self-developed. Takinga SUV for example, takeing external flow field and engine compartment coolingsystem into account contemporary, this paper analyzed and researched on SUV’saerodynamic characteristics, improved numerical results has the guiding sense to theSUV’s designing and developing, which is also contributing to enhance China’sAutomotive industry R&D capabilities and ability of independent innovation.Based on the turbulence model and grid selected, takeing air convection and thesurface thermal radiation of hot parts into account contemporary, this paper make thenumerical simulation of the SUV, get the original aerodynamic characteristics of theexternal model and engine compartment the results of the flow and thermalenvironment, and then through the flow of external flow field analysis, mechanism ofthe external flow field and features is on discussion, the reason why the drag wasproduced is clear. It provides references for the following work of drag reduction.Next, by means of analysising thermal performance of the engine compartment, thepaper have maken some improvements in the engine compartment cooling solution,while the results show that the heat of the SUV’s engine compartment cooling system performance characteristics and also have a larger increase.