title: Effects of moving-vehicle wakes on pollutant dispersion inside a highway road tunnel.
abstract: This study investigates the pollutant dispersion in a highway road tunnel in the presence of moving-vehicle wakes by a relative-velocity approach using 3-D CFD (3-Dimensional Computational Fluid Dynamics). The turbulent behavior of airflow around different-shaped vehicles and its impact on the pollutant dispersion have been studied. The different-shaped vehicle geometries were extracted, and simplified and dimensioned basing the typical vehicles on Indian roads. The model has been verified with the literature data of static pressure around a moving vehicle body before applying to simulate concentrations, and validated with on-site data at two locations. The results showed that wakes varied with the size, shape and speed of vehicles. The mixed-traffic flow produced higher near-field wakes and accelerated the piston effect, pushing pollutants toward the tunnel roof and out of exit portal in short-time. The findings have particular significance in the studies related to dispersion inside the tunnels having a mixed traffic of different dimensions and shape.
authors: Department of Civil Engineering, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India.
authors: Utkarsh
authors: U
authors: Bhautmage
authors: Department of Civil Engineering, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India. Electronic address: sharadbg@iitg.ernet.in.
authors: Sharad
authors: S
authors: Gokhale
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D000397:Air Pollution / Q000032:analysis*; D004784:Environmental Monitoring / Q000379:methods*; D006801:Humans; D008962:Models, Theoretical; D055585:Physical Phenomena; D001335:Vehicle Emissions / Q000032:analysis*
chemical_list: D000393:Air Pollutants; D001335:Vehicle Emissions
keywords: Air quality; CFD; Dispersion; Highway tunnel; Vehicle wake; Vehicular emission