Far-Field Drag Prediction and Decomposition Method for Unsteady Flows

摘要

Far-field drag prediction and decomposition methods are powerful tools that increase the accuracy of the drag coefficient 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 flows. This paper presents a new drag prediction and decomposition method relevant to unsteady flows. This new method is defined 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 identification of a type of drag caused by the unsteady fluctuations of the flow. This method is designed for 3D viscous, subsonic or transonic flows.