Flow and Dispersion Characteristics Around Buildings: Numerical Evaluation

Predicting gas dispersion from chimneys in urban environments is essential for minimizing impacts on air quality and human health. This study presents a numerical investigation of pollutant dispersion under turbulent flow, accounting for the influence of buildings and obstacles in a realistic industrial setting. Flow dynamics, heat transfer, and pollutant transport are analyzed to understand emission behavior in the near-field region. A parametric analysis examines the effects of chimney height, velocity ratios, and building placement. Results show that topography and structural features significantly alter wind patterns, pollutant concentration, and plume trajectory, particularly near ground and building levels. Chimney height proved the most critical factor: taller chimneys promoted wider diffusion before ground contact, whereas shorter ones caused plume looping and localized pollution. The findings support the design guideline that chimneys should be at least 2.5 times the height of nearby structures.

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