Independent Two-Fields Solution for Full-Potential Unsteady Transonic Flows

The paper introduces a new approach for the numerical solution of full-potential unsteady flows based on an independent approximation of the density and velocity potential fields. The solution procedure relies on an, unstructured, node-based, finite volume approximation, with linear shape functions and nonreflecting farfield boundary conditions. An improved upwind density biasing allows us to stabilize the solution in supersonic regions. In view of linearized aeroelastic stability and response analyses, unsteady boundary conditions are accounted for by means of a density flow transpiration. Time marching solutions are dealt using first/second-order implicit schemes, whose unconditional linearized stability properties are demonstrated. A few applications are presented to validate the method.