Numerical Simulation Of External Flow Field Around The Microbus

The aerodynamic performance is one of the most important parameters for road vehicles, which has a great effect on the motivity, fuel economy and handling quality. And the main factor of affecting these performances is the flow characteristics around vehicles. Numerical simulation is becoming important means that studies the automobile aerodynamic problem.On the numerical simulation of the external flow field around road vehicles, boundary conditions, cell type and distribution, turbulence model and solution algorithms can affect the result very much. The model characteristics and request of microbus are different from car and so on. So it is theoretic significance and practical value that study the numerical simulation of the external flow field around the microbus. Compared the results of numerical simulation under the two different ground boundary and eleven different calculated domains, the following points can be concluded:①The different ground boundary, moving ground and stationary ground, obviously affects the flow field of the underbody but little of the upside.②The different ground boundary greatly affects the aerodynamic lift coefficient and the front tire lift coefficient but little affects the aerodynamic drag coefficient and the rear tire lift coefficient.③The aerodynamic drag coefficient decreases with the extension off front inlet boundary, but the aerodynamic lift coefficient increases.④Increasing with the width of the calculated domain, the aerodynamic drag coefficient and the aerodynamic lift coefficient is lower, but the change is not too when side-domain reaches one width.⑤The rule of the aerodynamic drag coefficient and the aerodynamic lift coefficient is not obvious when we change the distance of the rear domain.⑥On the numerical simulation of external flow field around the microbus, it is felicitous that the front calculated domain is two times than microbus'length, that the calculated domain of the side is three times than microbus'width, that the rear calculated domain is six times than microbus'length.