Fig. 6.

Typical dispersion patterns and re-entry ratios of tracer gas from different sources around a slab-like multistory building with different wind directions. Red dot: tracer gas source. (From: Ai et al. [37], [38]). The wind-dominated pollutant dispersion is studied by Ai et al. [37], [38] considering a wind speed of 1 m/s at roof height; The threshold used to exclude results is: re-entry ratio <0.1%. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)