The Vehicle Cooling And Ventilation Optimization Research Of Chassis Dynamometer Test

With the continuous development and progress of science and technology, China’s auto industry is also in constant innovation and development. Put forward more and more requirements of people on the auto safety, power performance, economic properties making the test technology of automobile got unprecedented development and wide application of. The vehicle chassis dynamometer is a kind of indoor bench test equipment that can achieve precise simulation of all kinds of automobile road test condition, and is an indispensable important test equipment in the automobile product development, test and research, quality inspection. Vehicle traveling on the road is a kind of longitudinal motion relative to the static pavement, while in a chassis dynamometer test, the test vehicle in drum-type chassis dynamometer simulating road conditions, driving wheel rolling on the drum, but in fact with respect to the ground and the base vehicle did not move, so there is no air flow as road driving around the test vehicle, the heat generated will gather around the test vehicle, resulting in the lack of heat radiation, which will lead to excessive thermal load of engine and vehicle components, thereby reducing the reliability and durability of them, and affect vehicle fuel economy, power performance and emission performance, will affect the safety and the accuracy of the results in the tests, even can cause great damage to the test vehicle and a threat to the security of testers. Therefore, it is necessary to study on vehicle for ventilation and heat dissipation in the chassis dynamometer testing, through the analysis of the cooling air flow and the temperature distribution, design a scientific, rational, economic and effective cooling ventilation scheme.In this paper, we using the modeling software UG to establish 3D model, carries on the grid division of the various computational domain through the ICEM software, and numerical simulation calculation and analysis using FLUENT software. Taking use of single variable principle, study of the effect of head-on cooling fan height and position to ventilation effect of test vehicle, at the same time, compare driving wheel cooling effect in different fan layout form, determined the reasonable head-on cooling fan and tire cooling fan layout scheme. Through the numerical simulation analysis of five different fan height model, comparing the simulation image and numerical results, finally obtains that when the fan center line overlap the center line of vehicle air inlet grille, cooling ventilation effect is best; Through numerical simulation analysis of the five different fan location model, comparing the simulation image and numerical results, finally obtains that when the horizontal distance between head-on cooling fan to the vehicle air inlet grille is almost 1500 mm, cooling ventilation effect is the best; It is also verified, in this paper, the importance and necessity cooling fan is provided with the casters and the supporting feet; Through simulation image and numerical results of comparing the two kinds of tire cooling fan layout form, finally obtains that when the tire cooling fan put as 45° angle, the cooling effect is better. And through the actual temperature and velocity values measurement of the key point of chassis dynamometer test, the research method and results in this paper are verified, which proves the accuracy and feasibility of this study.