FLOW CHARACTERISTICS IN THE RAILWAY TUNNEL WITH VARIOUS VENTILATION SHAFTS AND MOVING TRAIN

초록

The flow characteristics in the railway tunnel with two kinds of ventilation shaft are numerically investigated when a train is moving in the tunnel. One of the ventilation shafts is connected to tunnel with a sharp-edge (90o) and the other ventilation shaft is connected to tunnel with a slant-edge of 45o. The straight duct is assumed for the simple model of railway tunnel. The size of the duct is 210m(x) × 12m(y) × 6m(z) and a moving train is passing through the tunnel with constant velocity (1m/sec). The moving train is modeled by cylinder type body whose radius is 1.75m and its length is 10.5m. The cross-section area of vertical ventilation is 3.25m×3.25m and its length is 12m. Immersed Boundary Method (IBM) is applied to make it possible to analyze the relative motion of moving body in the tunnel. LES has been employed to simulate the flow in the tunnel. The Re is 1,500 based on the car radius. The turbulent flow fields which are generated by relative motion between train car and ventilation shaft are analyzed. The different flow behaviors caused by two kinds of ventilation geometry are compared with each other.