Conceptual Design and Simulation of Rear Pressure Different Air Flow Correction Device Using Computational Fluid Dynamic (CFD)

Abstract

Drag reduction is one of the most significant issues within the automotive industry. Pressure drag contributed more than 80% of the total drag and it is highly dependent on vehicle geometry due to boundary layer separation and formation of wake region behind the vehicle. The drag caused by pressure difference at the rear and front of the vehicle is a major issue for all car segments especially bluff body car segments because it contributed largest fuel consumption. Air suction or blown at the rear of the bluff body can alter the flow pattern of the air hence. This resulted in shrinking at the wake region which resulting in an increase of rear pressure and reduces the pressure difference between front and rear of the body. The objective of this study is designing a concept of drag reduction system that can change the pressure distribution and reduce drag coefficient (CD) of bluff body which is represented as Ahmed body model. The design and testing of the airflow correction device were aided by Computer-aided Design (CAD) and computational fluid dynamic (CFD). The concept of the rear air flow correction device altered the flow pattern which changes the pressure distribution and reduces drag coefficient by 4.5352%. Hence, with full of positive expectation, hopefully, this method of reducing drag by using rear suction or blown air flow correction device will be broadly used for bluff body car segments.