Investigation And Improvement On Underhood Thermal Management

Automotive aerodynamic characteristic is the premise and theoretical basis for the automobile body styling, and the investigation on underhood thermal management includes the performance of cooling package and the airflow characteristic of underhood, which are the key factors influence the dynamic characteristics, fuel economy and driving stability. Along with the development of automobile technique, the investigation on underhood thermal management has become one of the important and hardy problems for field of Computational Fluid Dynamics. This paper has carried out detailed research into airflow of underhood field and performance of heat exchange on Zhongqi program. Analysis of the results can give a beneficial basis for car designing, and finally coming to being a completely integrated method for designing of underhood thermal management will greatly promote research-independent and innovation ability of our country's automotive industry.A mathematical approach is developed to analysis the complex airside flow of underhood and external, which is used to investigate the airflow characteristic and temperature distribution of underhood at the vehicle conditions:idle, torque, simulation hill, power, high speed.Through analyzing the reason of temperature distribution to estimate the capability of cooling. And it can quickly and accurately guide the choice of cooling systems by applying joint 1D/3D numerical simulation.Finally, it is an exploration of the influence of front-end design parameters on underhood thermal management. And in this based on the airflow characteristic and temperature distribution of underhood, realizing the improvement of the underhood cooling,through improve the front-end design parameters, the underhood part, and the additional devices of underbody. At the vehicle conditions, the air flow of intercooler,condenser, radiator, and fan module increased by 4.2%,4.8%,5.7%, 5.6%;radiator outlet side temperature decreased 6.7℃, Intercooler outlet side temperature decreased 5.2℃;the highest surface temperature of engine sump tank decreased 15.5℃;engine water temperature decreased to 108.8℃,by 5.4%; the engine intake temperature decreased by 1.2%. This provides a reference to thermal management by the result of the numerical simulations.