高速列車進入隧道或地下月台時，強烈之氣流會造成巨大壓力變化，會造成音爆、列車阻力及能耗的增加和候車乘客的不適等問題。本研究採用三維可壓縮流計算流體動力學模式，計算高速列車進入隧道與兩輛列車在隧道內交會時所產生的風壓變化，以及列車在隧道內交會時的受力大小。紊流模式採用RNG k-e紊流模式計算列車在運動過程中周圍的紊流流場，模擬結果並與Ricco et al. (2007)的模型實驗及Glockle & Pfretzschner (1988)的德國Enmalberg隧道現地監測結果比較，以增加數值模式的可信度。 本研究利用此數值模式先計算單輛台灣高鐵列車700T進入長隧道的問題，以瞭解壓力波生成與在隧道內的傳播情形，比較列車形狀、假隧道和解壓孔對壓力波的影響。最後，本研究再針對兩輛列車在隧道內交會的問題進行一系列的模擬，研究列車速度、阻塞比、隧道長度、交會位置和對隧道內的壓力係數和車體的受力係數之影響。研究結果顯示：台灣高鐵700T列車車頭形狀相較於長方柱形列車，可以緩解59%的壓縮波壓力與68%的壓力梯度，但車尾形狀則對其無削減作用。假隧道和解壓孔的設置無法緩解壓縮波的壓力峰值，但可以使壓力梯度分別降低25% 和37%，而同時設置假隧道與解壓孔於隧道出口效果最好，壓力梯度可降低58%。當兩輛列車在隧道內交會且並列時，其車體會受到最大的側向吸引力，使得列車互相靠近，且此吸引力與列車速度的平方成正比，此結果與Hwang et al. (2001)一致。隧道內最大壓力會隨著車速與阻塞比的增加而增加。當兩輛列車阻塞比的增加會使得車體受到更大的側向吸引力，而隧道長度則對側向吸引力無影響。最後，當兩輛列車在隧道1/3處交會時，其所產生之隧道內最大壓力小於在隧道中央交會，但是交會位置不會對車體受力情形造成影響。The aerodynamics effects caused by high-speed trains entering a tunnel may induce many serious engineering problems such as the passenger discomfort, noise surrounding the tunnel entrance/exit and possible damage to the train body and tunnel facilities. A three-dimensional, compressible, turbulent model was utilized to investigate the pressure waves generated by trains/tunnel interactions. The turbulent flows generated by the moving train in a long tunnel were computed by the RNG k-e turbulence model. The numerical model was verified by comparing with the experimental results of Ricco et al. (2007) and field observation of Glockle & Pfretzschner (1988) in Enmalberg Tunnel. Then a series of numerical simulations of a single train traveling through a long tunnel were carried out to understand the effect of the train shape as well as the influences of the hoods and holes on the compression wave. Compared with a squared cylinder train, the nose shape of Taiwan 700T train can effectively reduce the amplitude and pressure gradient of the compression wave. The enlarged hood and holes at the portal are demonstrated to attenuate the pressure gradient 25% and 37%, respectively, and 58% when holes and hoods were adopted simultaneously. Finally, the simulation results of two trains passing each other indicates that the maximum positive +CPmax and negative pressure -CPmax occur at the middle of the tunnel when two trains pass each other at Xsc = 0.5 with the same speed. The effects of the length ratio on the aerodynamic forces are insignificant. The maximum positive pressure +CPmax increases as the train speed and the blockage ratio increases. In addition, the simulated results show that the maximum drag coefficient CDmax is resulted from the nose-induced compression waves. Also, the maximum suction force CSmax occurs as two trains are aligned side by side, and the side force is proportional to the square of the train speed. The maximum side force coefficient CSmax rises as the blockage ratio increases. Compared to Xsc = 0.5, when two trains passing each other at Xsc = 0.67 with the same speed, the maximum positive +CPmax becomes small. However, the intersecting location is independent on the side force coefficient CSmax and the drag coefficient CDmax.
