Design of Transonic Airfoils and Wings Based on the Solution of the Euler/Navier-Stokes Equations

A design method for transonic wings based on the solution of the Euler/Navier-Stokes equations is described. The applied design strategy is a residual-correction approach developed by Takanashi. The difference between the computed pressure distribution of a given geometry and the prescribed target pressure distribution is iteratively reduced by the solution of the transonic small perturbation (TSP-equation). In this design method an analysis code is required, such as the Euler/Navier-Stokes code CEVCATS developed at DLR. Takanashi's method must be modified in order to guarantee the convergence of the design in transonic flow. In addition an algorithm to smooth the contour is used to obtain a smooth surface. In LARA 1.2 the characteristics of the design method are investigated on the basis of the design of transonic airfoils as well as wings in order to estimate the accuracy and convergence