Two-point velocity statistics and the POD analysis of the near-wall region in a turbulent channel flow

The Particle Image Velocimctry (PIV) measurements in the near-wall region of a turbulent channel flow have been performed. Two-point velocity statistics are obtained from experimental data and further subjected to the Proper Orthogonal Decomposition (POD) analysis. The resulting empirical function basis characterizes the inhomogeneous shear flow. The first eigenfunction together with spanwise statistics is used in order to find an approximate velocity field of a typical eddy structure.