Simulation Analysis Of Car Flow Field With Underhood And Ground Effect

In the course of studying vehicle aerodynamics domestic and overseas, because wind tunnel tests cost too much, CFD technology is widely used. We have got great achievements during recent years. Utilizing CFD technology and FLUENT software, this paper analyses the effects of underhood and ground effect on car flow field, and explores simulation methods on studying car flow field with underhood. On the basis of this simulation above, this paper solves engine and radiator match problem by approach of theory analysis and numerical calculation .The contents of this paper as follows:(1). Ground effect and underhood have great effect on car flow field and CFD technology has proven to be an effective approach to offer the car's aerodynamic capabilities beforehand.(2). Build the car body model by CATIA, in the calculation of flow field three-dimensional unsteady Navier-Stokes equations are solved by choosing RNG k -εmodel equations, request its answer iteratively by SIMPLEC method. And apply GAMBIT software to build the structure-unstructure hybrid mesh, FLUENT software to dispose its data. Carry on the simulations to two models, and one without ground effect and the other consider the ground effect. The result gives the flow field and pressure field and so on.(3). Add underhood to the model given in (2), Carry on the simulations to model with underhood.(4). Give the comparison and analysis on the simulation results. The result of the simulation indicate that: influence of the underhood and ground effect on a car aerodynamic performance is very obvious. It is also effective and economical method to cab flow field research.(5). Based on the results given above, analyze the car's heat dissipating performance. CFD methods can also be used in studying car temperature.