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By means of three-dimensional CFD numerical simulation method, the spatiotemporal distribution law of aerodynamic pressure on the tunnel wall and vehicle surface in the horizontal and vertical directions during single vehicle passage and double vehicle intersection of CR400 EMU with a speed of 400 km ∙ h-1 is studied, and the negative pressure area and boundary conditions on the tunnel wall and vehicle surface are quantified. The results indicate that the aerodynamic pressure inside the tunnel can be correlated with parameters such as vehicle type, train speed and tunnel length to form a theoretical model. When different types of single vehicle pass through the tunnel at a speed of 400 km ∙ h-1, the difference in peak aerodynamic pressure acting on the tunnel wall is limited. Compared with the CR400BF EMU, the CR400AF EMU only increases the positive peak of aerodynamic pressure by 1.1% and the negative peak of aerodynamic pressure by 0.9%. The aerodynamic pressure on the surface of the EMU shows high uniformity in both the horizontal and vertical directions. During single vehicle passage and double vehicle intersection, the surface of the vehicle body is basically in the same pressure state at the same time. At different tunnel lengths, when the speed of the EMU is 400 km ∙ h-1, the negative pressure of the expansion wave at the center of the tunnel and the negative pressure of the high-speed train body itself are superimposed when a single vehicle passes through the tunnel, and the negative peak value of the aerodynamic pressure borne by the body reaches -4.60 kPa. When 2 vehicles intersect at different positions with a constant speed inside the tunnel, the maximum negative pressure occurs at the intersection condition of the tunnel center, and the negative peak value of the aerodynamic pressure reaches -9.68 kPa. When 2 vehicles intersect at a constant speed in the center of the tunnel, there is an unfavorable velocity boundary that significantly strengthens the negative pressure effect in the intersection negative pressure area.
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| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |
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