High Spatial Resolution PIV Measurement of a Self-similar Adverse Pressure Gradient Turbulent Boundary Layer

Adverse pressure gradient (APG) turbulent boundary layer (TBL) flow, common in diffusers, turbine blades, aircraft wings, and marine vessels, can cause flow separation, leading to loss of lift and increased pressure drag. Understanding APG-TBL flow is crucial for designing efficient aerodynamic surfaces and controlling flow separation. This study uses high-spatial-resolution (HSR) 2C-2D particle image velocimetry (PIV) to measure a self-similar APG-TBL. Establishing a self-similar APG-TBL (SS-APG-TBL) isolates the effects of pressure gradients from upstream conditions. In a SS-APG-TBL flow, the statistical profiles of the flow collapse if the velocity is normalised by frictional velocity and the length are normalised by viscous length which allows the flow profiles have the same shape in this region.