Air Dispersion Modelling and Wind Tunnel

This technical report presents an analysis of air dispersion modelling using wind tunnel experiments to study the aerodynamic behavior of cylindrical and flat plate aerofoil models, specifically the AF101 cylindrical stack model and the AF106 flat plate boundary layer model. The experiments were conducted to investigate the effects of different wind velocities on the pressure coefficient distribution around the cylindrical stack and the boundary layer development on the boundary layer model.For the AF101 model, the study focused on determining the pressure distribution around the cylindrical stack under varying wind conditions to understand the pollutant dispersion that could influence downwash concentrations. The results indicated significant variations in pressure coefficients due to changes in Reynolds number as flow transitioned from laminar to turbulent flow around a cylinder and predicted that higher turbulence flow results in formation of narrower wakes and greater pressure recovery resulting in higher horizontal and vertical dispersion of pollutants.The AF106 model was used to simulate the atmospheric boundary layer, focusing on the impact of surface drag on the boundary layer's development. The findings showed that boundary layer thickness increased with distance from the surface and was more pronounced at higher wind velocities, highlighting the role of turbulence in enhancing vertical mixing and pollutant dispersion.The report concludes that understanding the aerodynamic behavior of these models under different wind conditions is crucial for optimizing industrial stack design and improving environmental safety by reducing the downwash and enhancing pollutant dispersion away from ground-level receptors