We need to make the correction of maximum lift coefficient for free flight condition from wind tunnel test by help of CFD analysis. However, we have the difficulties in CFD analysis accuracy at Landing configuration (Fully flap Extended)
Any suggestion for Reynolds Correction of the maximum lift coefficient from wind tunnel test models results?
Thanks
Hi, the problem you face is that the response of the aerofoils to Reynolds number is highly non-linear. The performance of the wing is clearly dominated by the boundary layers on its surface. These start off laminar at the leading edge and then grow towards the rear. The Reynolds number based on momentum thickness grows as the boundary layer extends rearwards. There will be roughness elements on any real wings e.g. rivet heads, joints and dead flies. The curvature of the wing reduces causing diffusion and pressure rise in the flow direction. All these things encourage separation and or transition. These are classically hard to predict non-linear processes, they will change the lift and drag of the aerofoil. So my answer is that there is no simple correction. You could experimentally add a boundary layer trip to fix transition, or computationally set the intermittency to 1.0 at a fixed location. The response of the wing will then be much more linear!
Thanks Martin George Rose
However, our problems are we have the experiment data sets of 20% scale model at several different Rey. numbers. We need to do the extrapolate to free flight condition. But I am not sure about the method that we used to extrapolate the maximum lift from WT
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