Evaluation of the effect of horizontal holes in the tall buildings on the distribution of fine dust

Fine dust is one of the environmental challenges in dry areas, which disturb human comfort. Wind is the main factor in the movement of fine dust, and the movement pattern of wind is affected by the architecture of cities. The presence of a hole in the form is one of the design which affects the wind load and the flow of fine dust. The purpose of this research is to compare the distribution of fine dust in a tall building with horizontal cavity, with variable number and volume of cavity.

Numerical study was done by CFD. K-omega-SSD turbulence model is used. In order to the software data (the size and type of particles), the field sampling method has been used.

The findings of the research show that as the number of holes increases in volume and their size decreases, the wind speed inside the holes decreases and on the other hand, the movement behavior of the wind and accordingly the dispersion behavior of the particles become more uniform. In these cavities, the concentration of suspended particles increases and their size becomes smaller.

The results show that the design of the form with more holes and smaller volume is more suitable to deal with the phenomenon of fine dust and to achieve comfort in indoor environments. In addition, the design of the openings at higher heights and the depth of the holes reduces the settling rate of fine dust particles in the interior spaces.