Influence of rotational flow phenomenon in tunnel air shaft on pollutant dispersion

Based on the CFD simulation and the test data, the dispersion of pollutants from air shaft under considering rotational flow model and surface source model is compared, and the environmental impact is evaluated by landing concentration. The research shows that due to the limited construction conditions, the air shaft deviates from the upward side of the tunnel, resulting in the phenomenon of rotational flow, so the existing surface source model underestimates the pollutant dispersion effect of the air shaft.