Characteristics of fluctuating wall-shear stress in a turbulent boundary layer at low-to-moderate Reynolds number
Jianjie Wang, Chong Pan, Jinjun Wang
Abstract
Particle Image Velocimetry is used to measure the wall-shear stress (WSS) in a smooth-wall turbulent boundary layer at low-to-moderate Reynolds number. The fluctuating intensity of WSS is found to follow an empirical log-law with Re due to the effect of outer-layer large scale motions (LSMs) on the wall. A scale decomposition analysis suggests that the LSMs leave a mild footprint effect on the WSS in the present Re range. The amplitude modulation effect is inferred to play a more prominent role in affecting the characteristics of fluctuating WSS.
Topics & Concepts
Particle image velocimetryBoundary layerReynolds numberTurbulenceMechanicsShear stressReynolds stressLaw of the wallWater tunnelBoundary layer thicknessTurbulence kinetic energyMaterials sciencePhysicsVortexFluid Dynamics and Turbulent FlowsWind and Air Flow StudiesParticle Dynamics in Fluid Flows