Analysis on statistical properties of pollutant in an urban block array by LES

Abstract

Fluctuation of concentration under the condition of building shaped obstacles array were analyzed by means of Large Eddy Simulation(LES). Stochastic properties were compared to the experimental results. Test region is the space which were pinched by two blocks centrally-located on the obstacles alignment. Although mean concentration of LES overestimated the value, relative properties such as skewness showed an agreement. The terms included in the transport equation of scalar variance were calculated. Peak location of variance and production of it were corresponded. The time scale ratio of scalar variance and kinetic energy were plotted in the target domain. The properties shows variability, however, it showed an agreement with an empirical value in the region where mean concentration took large value.