Multidisciplinary applications of detached-eddy simulation to separated flows at high Reynolds numbers (challenge 92)

摘要

The current effort develops and demonstrates the application of high resolution turbulence modeling to flight mechanics and aeroelasticity of air vehicles at flight conditions where the vehicle is experiencing massively separated flow fields. The effort has both a basic research component to aid in developing the method and an applied component where the method is used to demonstrate an ability to simulate current DoD aircraft issues in flight mechanics and aeroelasticity. The high resolution turbulence method is a hybrid Reynolds averaged Navier-Stokes (RANS)-large eddy-simulation (LES) method introduced by Spalart et al. in 1997 called detached-eddy simulation (DES) implemented in an unstructured Navier-Stokes solver, Cobalt. In the basic research component, DES has been applied to an Aerospatiale-A airfoil at an angle of attack of 13.3 degrees and a Reynolds number of 2 million. The project is called DESFOIL and simulates laminar-to-turbulent transition, adverse pressure gradients, streamline curvature, and boundary layer separation of a 3D airfoil strip. This study is in the early stages of developing a baseline for RANS and DES computations. DES has also been applied to flight mechanic and aeroelasticity problems of DoD air vehicles to demonstrate the utility of DES and also discover some of the nonlinear mechanisms causing these flight issues. The applications studied include the F/A-18E forced motion about the roll axis and one degree of freedom simulation of abrupt wing stall (AWS), the F/A-18C at conditions of tail buffet, and the ARGUS missile at conditions where it experiences coning motion.