A Spectral Model for Inhomogeneous Turbulence Applied to the Prediction of Turbulent Heat Flux and Temperature Spectra

A spectral model for inhomogeneous turbulence ("S.C.I.T." for Simplified Closure for Inhomogeneous Turbulence) has been developped during the last few years in our Laboratory. The main feature of the model is that it does not require any equation for the dissipation. Instead the equation for the turbulent kinetic energy spectrum is solved at each wave-number. The model was implemented in a finite element code solving the Reynolds Average Navier Stokes equation, and it was successfully applied to diffusive turbulence, boundary layers, pipe flows, flow over a backward facing step and to a wall jet.

The model is now being developped to incorporate heat flux prediction. An equation for the spectrum of the temperature fluctuation has to be included (closed in the framework of the Eddy Damped Quasi Normal Markovian two-point closure theory). The turbulent heat flux is predicted using a spectral extension of the [Shih and Lumley, 1993] model. The model is applied to the [Sirivat and Warhaft, 1983] experiment and compared to Large Eddy Simulation results [Chasnov, 1994].