Application of exceedance probability for local air change rate in evaluating the wind ventilation performance within densefo urban oreas study on wind environment in urban block (part 2)

The present study aims to estimate the minimum requirements for residential houses from the air quality point of view. Three typical models of a lngh'density built'up su'ea weri considered and numerical simulations were carried out, in order to examine the effects of the geometry of such models on wind flow characteristics, which in turn affect the air quality within the pedestrian domain of a street located within this area. The calculated flow field* wese employed to estimate local air change rater, which wele used to compute the probability of' exceeding the local air change rate which is calculated at the refeience conditions of the considered location. 'Pie present study has been applied on the most famous 9 cities in Japan: Sappoio, Sendai, Niigata, Tokyo, 'Ybkohama. Nagoya, Kvoto, Osaka, and Fukuoka based on theit mean wind velocity data. The jesuits demontrated that the exi'eedance probability analvsi, of tive pedestrian wind environment i very usefi.il in the evaluation of pollutants removal fticiencv b the applied wind. Mso the calculated probabilities showed large dependency on both the geolni try of'bcrildin, arrays and the wind conditions of the t3 cities.