Abstract: Automobile tail vortex is one of the main sources of vehicle's aerodynamic drag, and it is directly related to the shape of the rear vehicle body. MIRA standard model group was chosen in our study. Surface pressure measurement technique and Particle Image Velocimetry (PIV) technology were used in the wind tunnel tests to obtain the drag coefficient of the model group. The surface pressure distribution contour and the tail flow field on the longitudinal symmetry plane were obtained for qualitative and quantitative analyses of the model group and the relationship between the aerodynamic drag and the rear vehicle body shape is obtained. It is shown that: in the model group, the slope back model has the smallest resistance coefficient, the stepped back model has a slightly larger coefficient, and the straight back model has the largest; At the same time, in the tail negative pressure area, the distances between the tail vortex core and the vehicle body, and the tail vortex diffusion area see a tendency of increasing among these models.
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Received: 28 December 2010
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Corresponding Authors:
Wang Shi
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