후드를 이용한 협소 터널 미기압파 감소 효과에 대한 수치적 연구

초록

The train entry into a tunnel generates a strong compression wave in the tunnel. The high amplitude of compression wave causes high pressure gradients that are responsible for both the aural discomfort of passengers and the impulsive acoustical wave called the miro-pressure wave. This paper provides a numerical study on effects of hood for micro-pressure wave reduction. An axisymmetric numerical solver, considering the cross-sectional area of Korean Tilting Train eXpress, is used for a transient flow field in the tunnel. Results show that the micro-pressure wave is able to be reduced by a hood. In this results, the maximum reduction of micro-pressure wave is shown at 2L(length), 1.35D(diameter) hood around 56% against the non-hood case.