Development and Validation of a Partitioned Fluid-Structure Solver for Transonic Panel Flutter with Focus on Boundary Layer Effects

Abstract

A partitioned fluid-structure coupling code for transonic panel flutter has been developed and validated. The Reynolds-averaged Navier-Stokes equations are solved numerically by means of an implicit finite volume method to account for nonlinear aerodynamics, as there are shock waves and a viscous boundary layer at the panel surface. An implicit finite element formulation of the structural equations as well as a Galerkin solution of the von-Kármán plate equation are employed to solve elastic panel deformations with respect to geometric nonlinearities. A detailed validation process is presented in this paper for high subsonic and low supersonic Mach numbers. This comprises a discussion of available results from literature with the objective to propose a guideline for validation purposes of partitioned panel flutter solvers. Thereupon the code is used for studies on the impact of turbulent boundary layer characteristics on aeroelastic stability boundaries and post-flutter. An evaluation of flutter modes and frequencies in the post-flutter domain as well as a discussion of the corresponding flow phenomena is presented.