Estimation of validity of nonlinear models for pressure-strain rate correlations in turbulent flow

Simple inequalities obtained from the spectral representation of pressure-strain-rate correlations are used for analyzing nonlinear (in anisotropy parameter and mean strain rate) models of these correlations. These inequalities can be treated as a new criterion of the validity of the models relative to the known realizability conditions. It is shown in particular that the requirements following from this criterion are not met in the entire physically accessible domain even for models automatically satisfying the "strong realizability" conditions. In many cases, violations are observed at a high, but not exotic, degree of anisotropy corresponding, for example, to the wall regions of a flow in a channel. On the other hand, the new criterion turns out to be constructive in model "calibration." In particular, some simple constraints on the values of constants are obtained for some types of models proceeding from the conditions of the fulfillment of this criterion.