Modeling of the turbulent enstrophy equation

Abstract

Though the turbulent enstrophy and turbulent dissipation rate equations have many similarities, the former lacks expressions involving the pressure whose modeling has proved to be largely intractable. Moreover, it will be shown here that several of the production terms in the enstrophy equation may be analyzed through formal vorticity transport analysis. The result is a more careful accounting of production effects than has thus far been possible in the dissipation rate equation. When used with the conventional dissipation model, the new production terms significantly affect the enstrophy equation budget, but not the predicted mean velocity and turbulent kinetic energy. Thus, improved modeling of the enstrophy dissipation term is also necessary before the new production terms can have a beneficial impact on the computed flow fields. For low Reynolds number channel flow, a disspation model is constructed which demonstrates how accurate representations of the individual terms in the enstrophy balance can lead to improved predictions of turbulent quantities.