Inviscid Analysis of Transonic, Slatted Airfoils

Abstract

A numerical method is presented for the analysis of the inviscid flowfields about airfoils with leading-edge slats operating in the transonic speed regime. The method is based upon a previously developed, smalldisturbance theory for transonic airfoils, utilizing the geometrical advantages inherent in a preliminary conformal mapping to the complex potential plane of the incompressible flow about the body. In the current study, the mapping is performed for the main airfoil alone; the slat is incorporated using thin airfoil theory to displace the point of application of the slat boundary conditions to the nearest coordinate line of the computational grid. The finite-difference analog of the resulting equation for the perturbation potential is solved using typedependent line overrelaxation. Arbitrary slat-airfoil combinations can be treated, and agreement with experimental data is quite good for cases in which viscous effects on the slat are not too important.