Modeling Airflow in Urban Form against Sand Accumulation (case Study: Saltation in the Town of Timimoun in Southern Algeria)

In our present research, we focus on the modeling of airflow related to natural disasters, such as sand accumulation, with urban form studies. The objective is to find which urban form can promote sand passing and reduce as much as possible stagnation of sand in the building area (streets, alleys, etc.). The urban form design will be discussed through the simulation of airflow by using Computational Fluid Dynamics (CFD). In terms of simulation, we simulated the airflow behavior, which is responsible of sand stagnation in some specific configurations. A flat ground was chosen with a first configuration, which was varied to test each time a current airflow behavior in this configuration. This modeling is made possible following an appropriate turbulence model. In this study, a correlation was made between urban wind speed and morphological parameters such as aspect ratio, building geometry and building density. According to our theoretical references, this correlation shows that urban wind speed can help reduce sand stagnation with proper values of these parameters. Therefore, through the urban form study we can promote wind speed and blow away the accumulated sand till the urban limits