지하철 열차풍의 비정상 환기 특성

This paper describes the numerical calculation of inflow and outflow rates and average pressures on screen doors when a train passes through a subway tunnel system. The computational domain consists of a section of the main tunnel, two stations and four ventilation shafts. The calculation reveals an outflow of air through the 2nd ventilation shaft as the train approaches it. This is reversed after the train passes the 2nd ventilation shaft. As the train approaches the 3rd ventilaton shaft, its air outflow increases rapidly to a peak. Thereafter, the outflow rate first decreases steadly, then remains at a near constant value for a period of 20sec, and finally exhibits a small rise as the train draws into the ending station. The screen door at the starting station is found under the action of a negative pressure, of which the value drops steeply to its maximum as soon as the train leaves the station. In constrast, a positive pressure is computed on the screen door at the ending station, the magnitude of which attains its maximum as the train reaches its maximum speed. It is also found that when the 2nd ventilation shaft is moved 40m to the starting station, the maximum negative pressure of the screen door be come 11.5% smaller than the original set-up. Similarly, when the 3rd ventilation shaft is moved 14m to the ending station, the corresponding maximum positive pressure decreases by 25.9%.