CFD Investigation of Spacing Ratio Impacts on Plume Rise for Double-Inline Stacks

Specifying the emission characteristics of pollutants from point sources such as stacks and flares has always been an interest in environmental engineering. In the present study, by applying Computational Fluid Dynamics (CFD) the effect of the spacing ratio between two stacks with the inline arrangement on plume rise is investigated. The hydraulic diameter and height of the flumes are scaled to 1.27 and 10 meters, respectively, based on previous empirical investigations in the literature. Also, the distance between the stacks (called spacing ratio α) is considered the multiple of the hydraulic diameter in ratios of 3, 6, 9, and 18. Given simulation results by increasing the spacing ratio, plume rise occurs further from the downstream emission source. For the α=3 as a basis for comparisons, by double, triple, and sixfold the alpha value,  the shielding effect reduces 73, 112, and 154%, respectively.