Reduced-order modelling of urban wind environment and gaseous pollutants dispersion in an urban-scale street canyon

Hazardous chemical gases will spread rapidly after leakage. For emergency response to that, people need to obtain the information of wind and pollutant in time. However, it takes a lot of time to calculate the flow in large-scale urban areas by numerical simulation. Therefore, reduced-order model(ROM) is developed to improve the efficiency. In this paper, we propose a model based on proper orthogonal decomposition(POD) and radial basis function(RBF) interpolation. We validate the model by calculating the wind field and the pollutant propagation process in a 144 square kilometer area of Beijing. The results show that ROM can reduce CPU times by more than 99% at the cost of only 0.1% information loss, comparing with the traditional approach of computational fluid dynamics(CFD).