Computationally efficient turbulence model for pollution propagation simulation
L.I. Kurbatskaya1, A.F. Kurbatskii2
1Institute of Computational Mathematics and Mathematical Geophysics of the Siberian Branch of the RAS, 6, Ac. Lavrentieva ave., 630090, Novosibirsk, Russia
2Khristianovich Institute of Theoretical and Applied Mechanics of Siberian Branch of Russian Academy of Sciences, 4/1, Institutskaya str., Novosibirsk, 630090, Russia
Keywords: турбулентность, устойчивая стратификация, атмосферный пограничный слой, рассеяние примесей, моделирование, turbulence, stable stratification, atmospheric boundary layer, pollution dispersion, modeling
Abstract
The combined effect of orography and temperature stratification on the dispersion of pollutants in an urban heat island is simulated on the basis of three-parametric E - ε - <θ2> (Т-RANS) approach to thermally penetrating convection above the heat island. Two models of the concentration turbulent flow are used for the dispersion of a tracer from a surface source into a stably stratified atmosphere <uic > i.e., the implicit algebraic model and calculation from a prognostic equation. The correlation <cθ> between the concentration and temperature fluctuations is found from the solution of a prognostic equation in the both models. The algebraic model minimizes the difficulties in the simulation of turbulent transfer in a stably stratified atmosphere and provides for the results with acceptable accuracy as compared to the complete prognostic model of the concentration turbulent flow.
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