COMPUTATIONAL PREDICTION OF AIRFOIL DYNAMIC STALL

The term dynamic stall refers to unsteady flow separation occurring on aerodynamic bodies, such as airfoils and wings, which execute an unst eady motion. The prediction of dynamic stall is important for flight v ehicle, turbomachinery, and wind turbine applications. Due to the comp licated flow physics of the dynamic stall phenomenon the industry has been forced to use empirical methods for its prediction. However,recen t progress in computational methods and the tremendous increase in com puting power has made possible the use of the full fluid dynamic gover ning equations for dynamic stall investigation and prediction in the d esign process. It is the objective of this review to present the major approaches and results obtained in recent years and to point out exis ting deficiencies and possibilities for improvements. To this end, pot ential flow, boundary layer, viscous-inviscid interaction, and Navier- Stokes methods are described. The most commonly used numerical schemes for their solution are briefly described. Turbulence models used for the computation of high Reynolds number turbulent flows, which are of primary interest to industry, are presented. The impact of transition from laminar to turbulent flow on the dynamic stall phenomenon is disc ussed and currently available methods for its prediction are summarize d. The main computational results obtained for airfoil and wing dynami c stall and comparisons with available experimental measurements are p resented. The review concludes with a discussion of existing deficienc ies and possibilities for future improvements. (C) 1998 Published by E lsevier Science Ltd.