CHARACTERISTIC MEASURE OF THE DEPARTURE FROM THE EDDY-VISCOSITY MODEL

There is presented a direct evaluation of the departure from the eddy- viscosity model. This, widely used, concept of a clear physical meanin g has usually been tested experimentally via simultaneous turbulence m odelling of an eddy-viscosity coefficient v(T). Hence, the effect of t he basic model assumption remains more or less latent. In the followin g we propose a characteristic measure for a direct determination of th e departure from the eddy-viscosity model, i.e. independently from the choice of nu(T)-modelling from a great variety of available forms.