Active Drag Reduction of a Square-Back Ahmed Body with Wheels Based on Steady Blowing

Abstract:

In recent years， active flow control has been applied to study the drag reduction of vehicles. However， most researches only aim at some simplified vehicle models without wheels. In addition， the amount of drag reduction and net saved energy both still need to be further improved. In this paper， based on steady blowing on the base， the active drag reduction is numerically studied on three square-back Ahmed models， i.e.，the original Ahmed model，the Ahmed model with stationary wheels， and the Ahmed model with rotating wheels， respectively. First， this paper explores in detail the effect of wheels on aerodynamic characteristics without jet flow. Then， it focuses on the influence of the form of jet groove， jet angle， and momentum coefficient on the drag under wheel conditions. It is concluded that the optimum conditions are as follows： when the form of jet groove is continuous and is close to the edge of the rear of model， the jet angle is 45° and the momentum coefficient is 3%， the corresponding drag reduction and net saved energy can reach 9.5% and 12.7W， respectively.