MODELLING OF CANOPY FLOW OF THE VARIOUS ROUGHNESS ARRAYS

Method to determine the model coefficients applicable to staggered roughness arrays with various densities and configurations

Abstract

The final goal of this research is to develop a generalized canopy model describing the effects of obstacles with various configurations and densities, such as automobiles and pedestrians on wind environment and turbulent diffusion in urban areas. A series of wind tunnel experiments was carried out to measure wind velocity profiles and drag forces acting on five shapes of roughness elements with different densities. The two of them represented car shapes and the others represented human shapes. CFD predictions were conducted for the equivalent configurations as those implemented in wind tunnel tests. The numerical experiment was conducted by changing the coefficients of the developed canopy model. The model coefficients were optimized by comparing with the experimental data and a new method to determine the model coefficients and definitions of the shape factors applicable to various obstacles were proposed.