Parametization of aerodynamic roughness parameters in relation with air pollutant removal efficiency of streets

Abstract

A new approach for judging the air pollutant removal efficiency of streets is proposed, based on the relation between (1) the average roof level pollutant flux w' c' and (2) u* and the roughness parameters ZQ and za of the logarithmic wind profile. An analytical model for evaluation of ZQ and z<j is presented. Building density and streamwise relative building length turn out to be the key parameters. Predicted ZQ compares well with published experimental data, but fine tuning is not yet possible because of experimental uncertainties.