Two-dimensional Gram-Charlier reconstruction of velocity correlations

The two-point statistics obtained in a two-dimensional mixing layer and a three-dimensional wall jet are reconstructed from the summation of Hermite Polynomials. The use of Hermite Polynomials allows the rigorous and progressive decomposition of the statistical field into separate components, Gaussian and non-Gaussian. The influence of individual terms can then be investigated. Two different schemes are used: a one-dimensional temporal reconstruction of data from both experiments, which is capable of providing excellent agreement with the measurements, and a two-dimensional scheme with the mixing layer data, which captures spatial and temporal characteristics of the velocity cross-correlation. It is demonstrated that the technique can also recover information that may be lost or missing between two measuring points thereby providing a complementary method to linear stochastic estimation. (C) 1996 American Institute of Physics.