On the modelling of counter-gradient heat transfer in thermally stably stratified turbulent flow downstream of grid
A.F. Kurbatsky and L.I. Kurbatskaya*
Institute of Theoretical and Applied Mechanics SB RAS, Novosibirsk, Russia *Institute of Numerical Mathematics and Mathematical Geophysics SB RAS, Novosibirsk, Russia
Pages: 509–517
Abstract
To describe the counter-gradient transport of active (heat) scalar in a shear-free thermally strongly stably stratified flow downstream of a turbulizing grid both a completely differential model of transport for the first- and second-order moments and a completely explicit anisotropic algebraic model of gradient diffusion for active scalar were used. The results of computer modelling show that for a weak stratification the both models give a distribution of vertical heat flux in good agreement with measurement data. For a strongly stable stratification the effect of counter-gradient heat transfer is described only by the model of differential transport equation for the vector of turbulent flux of active scalar. In this case the numerical modelling results agree qualitatively with measurement data.
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