Experimental Study for Addition Rough Surfaces on a Vehicle Floor Body and Comparison of Aerodynamics Coefficient

After the invention of the automobile, people soon realized the relationship between air resistance and the movement of cars. Over time, the improved performance of the car from different directions and increase fuel price, improved aerodynamics also became the fundamental question. The researchers found that attention to aerodynamics not only to achieve higher speeds, but also appropriate to reduce fuel consumption and vehicle stability. That's why a lot of research has been done on the car's aerodynamics followed on.This article will examine the effect of surface roughness underside of the vehicle at some point. In this method procedure we study on two zones which have maximum probability of separation flow. These zones find on rear of wheels on floor of vehicle. Results compare with case which is smooth . We achieve to a unique conclusions. And also experimentally in wind tunnel tests, the optimum dimensions for rough surfaces are derived.