Numerical Study on Sensitivity of Pollutant Dispersion on Turbulent Schmidt Number in a Street Canyon

Abstract:

In this study, sensitivity of pollutant dispersion on turbulent Schmidt number (Sc_t) was investigated in a street canyon using a computational fluid dynamics (CFD) model. For this, numerical simulations with systematically varied Sc_t were performed and the CFD model results were validated against a wind‒tunnel measurement data. The results showed that root mean square error (RMSE) was quite dependent on Sc_t and dispersion patterns of non‒reactive scalar pollutant with different Sc_t were quite different among the simulation results. The RMSE was lowest in the case of Sc_t = 0.35 and the apparent dispersion pattern was most similar to the wind‒tunnel data in the case of Sc_t = 0.35. Also, numerical simulations using spatially weighted Sc_t were additionally performed in order for the best reproduction of the wind‒tunnel data. Detailed method and procedure to find the best reproduction will be presented.