Numerical approach on drag reduction for automotive vehicles

Mateus Brizotti, Patrick Rambaud and Florian Visentin


RESULTS with BLOWING CONTROL SYSTEM
Table of contents


Vortices and infleunce of the blowing velocity parameter


    Here is how we modelised the blowing control system with the aim of reducing the drag of the car. The blowing control  system is located at the right part of the rear window of the car as you can see on the picture
below . The width of the blowing slit is 10E-3 m.




        

    On the right picture, the votices are represented and we notice that they are broken by the blowing control system of which the blowing velocity was the same as the velocity inlet. We also did the unsteady simulations with the blowing velocity equal to twice the velocity inlet to look at the influence of the blowing velocity parameter on the drag reduction. The results that we got are summarized in the following link.

 

Results and influence of the blowing velocity parameter



Influence of the blowing control system on the pressure coefficient


      


    These pictures represent the pressure coefficient Cp distribution. This simulation was done with the blowing velocity equal to the velocity inlet. The first picture corresponds to the result we got without blowing system, and the second picture with the blowing system. We notice that blowing from the slit increases the value of the pressure coefficient on the top and the right part of the rear car. This result means that the destruction of the vortices by the blowing system involves a higher pressure value along the surface where the vortices were located.