Effect of Flow Separation Control with Suction Velocity Variation: Study of Flow Characteristics, Pressure Coefficient, and Drag Coefficient

Abstract

Flow separation is expected to have the effect of increasing aerodynamic drag due to decreased pressure distribution at the rear of the vehicle. The faster the flow separation occurs, the lower the pressure distribution is in the area, thereby reducing vehicle performance. Therefore, flow modification is needed with expected effects on the separation delay and the reduction in wake and vortex formation. This modification can be done through the application of suction active control in the separation area. The research is intended to analyze the effect of suction active control on flow characteristics, pressure distribution and aerodynamic drag on vehicle models with suction velocity variations. The test model used is an Ahmed model modified by changing the orientation of the flow. The study used a numerical computational approach with a standard k-epsilon turbulence model at 19.4 m/s upstream velocity. Results revealed that the use of flow active control was able to reduce wake and vortex formation through separation delay and to increase the minimum pressure coefficient by 73% on the model with Usc2 suction velocity of 0.5 m/s, gaining the highest drag coefficient reduction of 10.897% in the same model.