Modelling turbulent free convection in a mixture layer

The Reynolds and Peclet numbers of a buoyancy-driven mixing layer have been calculated within the framework of a numerical model. Turbulent transport in the model was calculated using equations for third-order turbulent moments. Profiles of turbulent fluxes were computed, and the results were compared with laboratory observations and in-flight measurements of the vertical flux of turbulent energy in a mixing layer. It is shown that the vertical flux of turbulent energy is a countergradient over the entire height of the mixing layer.