Simulation of Supersonic or Hypersonic Aeroelasticity Basing on Local Piston Theory
基于当地流活塞理论的气动弹性计算方法研究

Existing piston theory for supersonic flow can only deal with thin supersonic wing with sharp leading edge at small angles of attack. The unsteady CFD technology basing on Euler/N-S equations can solve the unsteady aerodynamic loads precisely, but it often needs much computational time even just for a simple 3D shapes. This paper presents a local piston theory for calculating supersonic unsteady aerodynamic loads due to structural motion or deformation. A steady flow solution is first obtained by an Euler method. The piston theory is applied locally at each point on the airfoil surface on top of the mean steady flow field to obtain the unsteady pressure perturbations caused by the deviation of the airfoil surface from its mean location. Computations by this method are performed for a number of unsteady flows and flutter results. The results are compared with those by the classical piston theory and fully unsteady Euler calculations. Because the piston theory is used only locally, this method greatly reduces the limitations of the classical piston theory on flight Mach number, airfoil thickness, and angles of attack. Compared to the fully unsteady Euler method, the local-piston theory method is very efficient. Only one steady-state solution is needed for the time-domain unsteady calculations.