Study On The Infulence To Aerodynamic Effect Of High-Speed Railway Tunnel With Simple Opening

Recent years has witnessed the rapid development of CRH with many high-speed railways constructed and put into operation. With the increasing speed of the trains as the CHR booms, however, the aerodynamics phenomenon happening in the tunnel becomes more serious. Taking the BaoJi-LanZhou railway tunnel project as background, this article, emphasizing the research of the influence of the opening position of the hoods and opening ratio on the transient pressure suffered by the tunnel, will discuss the pressure fluctuation law within the tunnel set with single-opening decompression hoods with the speed of 350km/h.Via numerical simulation, this article is going to research the effect of the tunnel with or without hoods on the transient pressure, pressure summit and gradient. This article will analyze how the hoods of the cut-and-cover tunnel affect the pressure fluctuation within the tunnel, and with comparative analysis of the different positions of the opening of the hoods and opening ratio at the same time, the influence law of them on the transient pressure, its summit as well as gradient will come to light. By analyzing the effect under different construction conditions, the best combination will be given.It should also be noted that, through numerical analysis with various opening position, opening area and their different combinations, the conclusion of the optimal opening position, opening area makes sense only in specific working conditions. The different shape of the opening, will make the best of the opening position and aperture ratio change dramatically.