Some recent developments in the Lamb vector based aerodynamic force breakdown used the concept of vortex force in order to define the lift and to decompose the drag into lift-induced drag and profile drag. However, the Lamb vector formulation is based on moments and the associated force breakdown may depend on the reference point adopted for their computation. Yet, the force acting on an airplane cannot be dependent on this point. Thus, a systematic method based on the far field flow symmetries is here proposed in order to get rid of this dependence. A new formulation is then defined and tested for a two-dimensional transonic flow around an OAT15A airfoil and a three-dimensional flow around the wing of the NASA Common Research Model.

Recent studies about the Lamb vector have led to the development of the vortex-force theory, a formulation able to predict the aerodynamic force in compressible flows and decompose it into lift, lift-induced drag and profile drag. Here, a revised formulation of the vortex-force theory developed at ONERA in collaboration with the University of Naples is presented and applied to steady transonic flows. In the mathematical developments, special care is given to the presence of shock wave discontinuities within the flow field. The equivalence between the new definition, the Kutta-Joukowski lift theorem, Maskell's lift-induced drag formula and Betz's profile drag formula is emphasized. The revised formulation also presents several practical advantages: the decomposition is naturally independent of the reference point chosen for the calculation of moment transformations, and the computation can be performed in a better refined part of the grid. The formulation is finally tested on the NASA Common Research Model (CRM) wing-fuselage configuration in cruise flight conditions.

Some recent developments in the Lamb-vector-based aerodynamic force breakdown used the concept of vortex force in order to define the lift and to decompose the drag into lift-induced drag and profile drag. However, the Lamb vector formulation involves moment transforma-

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