EXPERIMENTAL AND SIMULATION STUDIES ON AERODYNAMIC DRAG REDUCTION OVER A PASSENGER CAR

The present experimental and simulation investigation includes aerodynamic drag reduction over a car by flow control using a vortex generator (VG) and spoiler. The model of the car was fabricated on the scale of 15: 1 using plaster of Paris. A test facility is built to convincingly replicate the flow over a model of a high-speed car. Primarily, the car model is tested at different incidence angles of flow to obtain total drag over the model. Furthermore, 26 different combinations were tested to find out the condition for minimum drag. In the crosswind condition (+/- 30 deg), 36.36% additional area of the car is exposed to the direct wind that causes an increment of 38.61% in the drag coefficient. The increment of flow angle from 0 to 30 deg causes flow separation on the roof of the vehicle near the leeward corner. The maximum 68.18% drag coefficient is reduced at beta = 0 deg, alpha = + 45 deg, and the co-rotating VG. The best combination in terms of a surface static pressure coefficient rise (from -0.041 to + 2.622) is found at beta = 0 deg, alpha = 0 deg, and the VG attached to the upstream of the spoiler. A formulated computational fluid dynamics model is in good match with the experimental results.