The Application Of Flow Control In Road Vehicle Aerodynamics

As one of the most important characters, the aerodynamic character has an extensive effect to theautomobile’s performance. Flow control is one of the hot spots of aerospace field and the leadingareas of research in fluid dynamics. If using flow control in the automobile’s aerodynamics, canimprove the aerodynamic performance of the automobile.As the background of this paper, noise, fuel economy, high aerodynamic drag and crosswindstability are main factors of the performance of the automobile. The classic Ahmed car model is usedas the experimental model, the wake flow structure is investigated. Flow control using vortexgenerator is advised to control the flow field of automobiles. Then the aerodynamic character ofpassive and active vortex generator is investigated. Based on it, the control result on the model isinvestigated, the control mechanism is also analyzed both and the application scheme in automotiveengineering.Based on the structure of the model wake, flow control using vortex generator is advised tocontrol the flow field of automobiles. The aerodynamic character of passive and active vortexgenerator is investigated. The wake of the vortex generator is measured by seven-hole probe whenchanging the figure, the angle of attack, the arrangement of the VG. The character of the wake flow isanalyzed and the key control characteristic is given.Based on the control characteristic, the VG is used to control the flow field of the Ahmed model.It is showed from the experiment that the VG can increase the wake field pressure and reduce thepressure drag effectively under appropriate parameters. The optimal result in this paper is13.53%ofthe Pressure recovery coefficient σ. Using a faint energy to reduce the pressure drag of the model isachieved.Finally, the aerodynamics force and wake structure of the model are investigated by balance andseven-hole probe. Integrating the force and the wake structure, the crosswind problem is analyzed.And controlling means are advised to further investigations.