A viscous interaction approach for analysis and design of airfoils and high-lift configurations

An accurate, comprehensive interactive boundary-layer method has been coupled with an analytic-based Euler equation solution method for the analysis and design of airfoils and high-lift configurations. The goal of this development effort is an efficient design process which includes all necessary physics (i.e., compressibility and viscosity). It takes full advantage of the efficiency afforded by an inverse boundary-layer method for predicting viscous effects. The boundary-layer method includes an improved Cebeci-Smith eddy viscosity formulation and computes transition onset using either the e exp n method or Michel's formula. The inviscid-flow method is significantly more efficient than the conventional CFD approach for inviscid flow prediction and provides full compressibility effects. It uses a sequence of transformations, mappings, and asymptotic methods which places the Euler equations in the form of a boundary value problem amenable to analytic solution using classical mathematical techniques. Results are presented for airfoils and two-element high-lift configurations which demonstrate the potential improvements that can be realized by this approach. (Author)