Modeling Airflow in Urban Form against Sand Accumulation: a Case of Saltation in the Town of Timimoun in Southern Algeria

Subject Areas : Urban Design

Djamel Mestoul ¹ , Rafik Bensalem ² , Luc Adolphe ³

1 - Ph.D. Candidate, Laboratoire Architecture et environnement (LAE), Ecole Polytechnique d’Architecture et d’Urbanisme, EPAU, Alger-Algérie.
2 - Professor, Ecole Polytechnique d’Architecture et d’Urbanisme, EPAU, Alger-Algérie.
3 - Professor, Ecole Nationale d’Architecture de Toulouse, Toulouse, France.

Received: 2015-10-01 Accepted : 2016-03-14 Published : 2016-06-22

Keywords: Computational Fluid Dynamics (, Sand accumulation, Saltation, Urban form, wake effect, Urban geometry,

Abstract :

In our present research, we focus on the modeling of airflow related to natural disasters, such assand accumulation, with urban form studies. The objective is to find which urban form can promote sand passing andreduce as much as possible stagnation of sand in the building area (streets, alleys, etc.). The urban form design will bediscussed 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 flatground was chosen with a first configuration, which was varied to test each time a current airflow behavior in thisconfiguration. This modeling is made possible following an appropriate turbulence model. In this study, a correlationwas made between urban wind speed and morphological parameters such as aspect ratio, building geometry andbuilding density. According to our theoretical references, this correlation shows that urban wind speed can help reducesand stagnation with proper values of these parameters. Therefore, through the urban form study we can promote windspeed and blow away the accumulated sand till the urban limits.

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