A numerical study of the heat-ventilation state of a portal tambour of a tunnel in winter

Numerical simulation of the heat–ventilation state of a portal tambour of a tunnel in winter is performed using the model of turbulent viscous heat-conducting compressible gas. The direct and reverse operating modes of heat–ventilation units (HVUs) located in the tambour are considered. The air intake and exhaust from the openings for the HVUs in the tambour occur at a 45° angle with respect to the plane of the wall. The following phenomena are taken into account when calculating the thermal state of the air mass in the tambour: air heating in the tambour due to operating HVUs; heat exchange between the air flowing from the outside into the tambour and the air in the tunnel; and heat exchange between the air flowing from the portal side into the tambour and the air in the tunnel. It is assumed that external cold air with a temperature of –43°C is flowing into the tambour at a volumetric flow rate of 100 m3 /s. The reverse operation mode of the HVUs ensures relatively uniform air flow along the height of the gate opening and does not allow cold air to penetrate from the outside into the tambour down to a depth of more than 10 m.