Construction of shock-free transonic flow

Not excluding a future application of the above ‘flow control concept’ we presently arc interest­ed m practical design methods, resulting in local shape modifications accomodating improved aerodynamic performance. The known FG design method combines the above flow control with a second design step replacing the controlled domain by an ideal gas supersonic flow pattern computed as outlined in paragraph 7.3.1. using the inverse method of characteristics or a 3D inarching. The airfoil example illustrated in Figure 40 results from this design computation. A summary of various implementations of the FG to fast potential flow solvers can be found in [89]. Later, the concept was introduced to the Euler equations |90) and Navier Stokes equations 191]. The latter method provides viscous design results based on FG models extending into the boundary layer, also it is a time-accurate computation allowing for unsteady aerodynamic appli­cations.

Some first attempts were taken to apply this design concept also to supersonic flows. As suggested by the shock-free infinite swept wing flow (Figure 40). a 3D supersonic flow design approach analog to the transonic method seems feasible |92J.