Computational Fluid Dynamics Analysis of an Innovative Multi-Purpose Green Roof

In this study, to improve the application and performance of conventional green roof systems, a novel multi-purpose green roof system was simulated numerically using computational fluid dynamics (CFD). The innovative multi-purpose green roof contains a soil layer and water filter, meaning the water retention time not only depends on the soil media but also depends on the filter’s pore size, improving the impact on runoff quality and quantity. In this regard, after mesh sensitivity analysis, the developed model was validated using experimental data, and the results show the accuracy of CFD in the simulation of porous media and filters. Comparisons between experimental and numerical results demonstrate the impact of proper porosity values in the simulation of a porous environment and reveal the source of errors in the numerical prediction of capillary flow in soil media, which can be minimized by adaptive consideration of the parameters, such as wall adhesion and appropriate wettability.