A new axial velocity defect formulation for a far-field drag decomposition method

Abstract

Current drag prediction and decomposition methods are based on the formulation of the axial velocity defect in the far-field as a function of entropy. However, the formulation of this axial velocity defect is not defined everywhere in the flow, owing to a possible negative square root under particular circumstances. This paper presents a new formulation for the axial velocity defect that is more robust and general than the current formulation. The proposed version shows the same accuracy as the existing formulation when the region of nondefinition of the axial velocity defect is relatively small, and it shows better accuracy when the region of nondefinition of the axial velocity defect is relatively large.