High accuracy determination of skin friction differences in an air channel flow based on pressure drop measurements

The present work delivers a versatile, accurate and reliable wind tunnel facility that is particularly developed to test different flow control techniques for drag reduction in precisely adjustable test conditions. Skin friction changes of 0.4%% are resolved, which is comparable to the most accurate reported studies in liquids. this high accuracy is verified through a comprehensive uncertainty analysis. Subsequently, various passive and active flow control strategies are investigated.