Representation of the spatial correlation tensor of the velocity in free turbulent flows

From experimental data obtained at a limited number of reference locations, a new method permitting to estimate the two-point spatial correlation tensor of the velocity on any mesh is presented. Firstly, a Gram-Charlier expansion is used to interpolate this tensor between reference points. Secondly, by using Proper Orthogonal Decomposition properties, this tensor is extrapolated on a larger mesh than the experimental one. An application of this procedure based on experimental turbulent plane mixing layer data is then shown. (C) 2000 Academie des sciences/Editions scientifiques et medicales Elsevier SAS.