CFD for Better Understanding of Wind Tunnel Tests

CFD requires validation for complicated flow problems involving complex physics such as turbulence. Wind tunnels are still the most commonly used validation tools for CFD including physical modelling although some limited use of reliable DNS data base for simple geometries is recently becoming possible. One can observe the trend that a higher and higher demand on the accuracy of the wind tunnel measurement as numerical simulation and CFD expand into more and more complicated flow regimes. This paper gives a few examples to demonstrate how CFD may be used in a reversed way to help wind tunnel to meet the challenges posed by both better understanding of flow physics and CFD validations.