Aerodynamic force and Lamb vector field in compressible unsteady flows

Abstract

A vorticity based theory for the computation and analysis of the aerodynamic force in steady and unsteady compressible flows is presented. It is the extension of a recent decomposition developed for incompressible flows. The breakdown in reversible and irreversible contributions is presented and a comparison with an unsteady thermodynamic drag breakdown is discussed. In particular, two physically completely different flows are analyzed: a pitching airfoil in subsonic flows and an airfoil natural buffet. A sensitivity analysis of the vortical method on the total force computation is presented. Then the breakdown results are compared and discussed.

Wave drag prediction using the Lamb vector in two-dimensional steady transonic flows

“…A main benefit provided by those two formulations is that they are directly invariant to the location of the reference point. Beyond all those developments and applications, the vortex-force theory has also been applied to inviscid flows [48], unsteady flows [49,50] and thrust prediction [51].…”