Influence of transition location on airfoil drag

Abstract

A comparison of predicted and measured laminar‐turbulent transition on the airfoil is presented. The MSES code is used for a prediction. The experimental data are taken from an experiment of W. Würz. Comparison of calculated results with measured data shows that the envelope of calculated individual frequencies coincides well with measured data in the transitional region for the attached boundary layer and for the separated laminar shear layer. For minimum drag, the laminar flow should be as long as possible and the shape parameter of the boundary layer at the transition should not exceed the value of 3.8. The optimum value of the shape parameter is 3.65 at Reynolds numbers from 1 to 2 million.

First Published Online: 14 Oct 2010

Keyword : laminar – turbulent transition, linear stability theory, e n method, laminar separation bubble, drag