The aerospace industry looks to CFD for the answer. Simulation can be used during the preliminary and conceptual design stages — before wind tunnel or flight tests are feasible. Design alternatives can be pursued with much more flexibility and at lower cost than in the wind tunnel. And CFD can, at least in theory, overcome the installation and scale effects of a wind tunnel.
However, the accurate simulation of the highly unsteady and complex flow over a high-lift wing (in particular, the prediction of maximum lift) is still out of reach for traditional CFD tools. Meshing of a full wing takes weeks and requires significant simplifications, with unknown effects on solution accuracy. In addition, simulations are generally steady-state, ignoring the important effects of the unsteady nature of the real world — particularly for high angles of attack when large regions of separated unsteady flow are dominating the lift performance.