The measurement of skin friction in turbulent boundary layers with adverse pressure gradients

摘要: This paper describes a floating-element skin friction meter which has been designed for use in adverse pressure gradients. The effects of secondary forces on the element, arise from gradient, are examined some detail. limitations various methods measuring wall shear stress discussed and results floating element device compared with measurements taken two-dimensional boundary layer using Preston tubes velocity profiles. As it is planned to instrument later direct three-dimensional layers, relevance this situation also discussed.