Comparison of Slipstream Flow in The Double-Bore Subway Tunnel With Different Shapes of Ventilation Shaft

초록

The slipstream flow patterns with different shapes of ventilation shaft are analyzed in the double-bore subway tunnel. The shapes of ventilation shaft have two types. One of the ventilation shafts is connected to tunnel with a sharp-edge(90°) and the other ventilation shaft is connected to tunnel with a slant-edge of 45°. Two trains are passing by each other in the double-bore tunnel. The size of model tunnel is 210m(z)ⅹ8.5m(y)ⅹ4.75m(x) and the velocity of moving train is ±1m/sec. The moving train is modeled by cylinder-type body whose radius is 1.75m and its length is 10.5m. Three vertical ventilation shafts are installed in each tunnel. Immersed Boundary Method (IBM) is applied to make it possible to analyze the relative motion of moving train in the tunnel. LES has been employed to simulate the flow in the tunnel. The Re is 1,500 based on the train radius. The turbulent flow fields which are generated by relative motion between moving train and ventilation shafts are analyzed. The ventilation efficiency is qualitatively investigated.