GENERAL VARIATIONAL PRINCIPLE FAMILY FOR FULLY 3-D UNSTEADY TRANSONIC FLOW WITH SHOCKS AROUND OSCILLATING WINGS

Based on the author’s previous work, a general form of generalized variational princi-ples (VPs) together with its derived VP family is established for 3-D unsteady’ transonicpotential flow with shocks past arbitrary wings oscillating periodically. To facilitate thenumerical handling, full use is made of functional variations with variable domain and natu-ral boundary conditions (BC) so that almost all boundary/interface conditions, including theRankine-Hugoniot shock relations and slip conditions across free trailing vortex sheets, havebeen converted into natural ones. Also distributed suction/blowing along the wing surfacefor the boundary layer control is accounted for. This theory aims at rendering a general,rigorous theoretical basis for the finite element metbod and other direct variational methods,and it can be generalized to both wing-body combinations and 3-D rotating bladings, includ-ing the subsonic flow as a special case.