Far-Field Drag Prediction and Decomposition Method for Unsteady Flows

Abstract

Fareld drag prediction and decomposition methods are powerful tools that increase the accuracy of the drag coe cient computed from CFD results by removing the spurious drag caused by numerical procedures. Furthermore, these methods allow a physical decomposition of the drag in terms of viscous, wave and induced drag. However, these methods are currently limited to steady ows. This paper presents a new drag prediction and decomposition method relevant to unsteady ows. This new method is de ned for both inertial or non inertial coordinate systems, hence allowing drag decomposition either on static, or on moving/rotating mesh. This new method also led to the identi cation of a type of drag caused by the unsteady uctuations of the ow. This method is designed for 3D viscous, subsonic or transonic ows.