Noise canceling to compute second order statistic from SPIV

Abstract

Stereoscopic PIV (SPIV) is performed near the wall in a turbulent boundary layer at high Reynolds numbers (Re_τ = 2272, 3840) in the streamwise-wallnormal plane. A novel method for denoising the statistics is proposed by the use to two independent SPIV systems to capture the same field of view, with the objective being that the random noise associated with the velocity fluctuations are not correlated between two independent PIV systems. The derivatives in the third (spanwise) direction are obtained by axisymmetry assumptions [George and Hussein (1991)] and continuity equation. The statistics are in agreement with that of DNS at comparable Reynolds number, from y ⁺ = 25 for lower Re_τ experiment and from y ⁺ = 40 for higher Re_τ experiment.