A Novel Approach to Uncover Mechanisms of Aerodynamic Forces Acting on a Body in Incompressible Flows

Based on the virtual power in fluid mechanics, a novel approach has been used to uncover the mechanics of aerodynamic forces acting on a body in incompressible flows. After the analysis of the typical examples, it is found that the instantaneous forces are composed of four types: 1) the unsteady effects (e.g. added mass forces), 2) the boundary kinetic energy flux (e.g. Magnus force) and dissipation effects (e.g. Stokes drag), 3) the flow structure contribution (so-called vortex force), and 4) the explicit body force contribution (e.g. buoyancy).