Prediction of Transonic Buffet Onset for an Airfoil with Shock Induced Separation Bubble Using Steady Navier-Stokes Solver

Abstract

A new steady approach method has been developed to predict the transonic buffet onset for an airfoil. In this study, the flow is assumed to be steady for the buffet onset. The present method involves the analysis of a distinct change in the variation of various aerodynamic parameters c alculated from a steady Navier -Stokes solver. These distinct changes indicate the onset of transonic buffet. Among the various aerodynamic parameters considered in the investigation, the variation in the center of pressure has shown to provide a clearest indication of buffet onset. This approach can be applied to predict the transonic buffet onset for an airfoil with a shock induced separation bubble, and a good agreement compared with unsteady wind tunnel test data has been obtained. In addition, compa red with the result of an unsteady method which required more computational time and memory, the present method is shown to be reliable and useful for transonic buffet onset prediction from the viewpoint of practical engineering application.