A generalized variational principle for inverse problem of 3-D unsteady compressible flow around oscillating wings

When the time-averaged pressure over the airfoil contour is given, while the corresponding airfoil shape is to be sought the inverse problem for 3-D unsteady compressible flow is incorrect or ill-posed. However, by the variational technique with a variable-domain, a variational model for the inverse problem is well established, which proves to be well-posed for the redundant data at boundaries.