In order to reveal the influence of the gate opening on the hydraulic characteristics of hydraulic tunnels, a two-dimensional model of silt-releasing tunnel with different gate openings was established. The VOF method and standard κ-ε turbulence model were used for three-dimensional numerical simulation calculation of flow field in abrasive section of flood silt-releasing tunnel. The hydraulic characteristics such as flow state, velocity and pressure near the gate were obtained. The hydraulic characteristics under different gate opening degrees were analyzed to obtain the cavitation number from the gate to the threshold. The results show that when the gate operation opening is less than 1/2 maximum opening, the larger the gate opening is, the smoother the tunnel flow state is, the smoother the flow velocity near the bottom is, the lower the pressure difference between the upstream and downstream of the tunnel floor is. The smaller the gate opening is, the smaller the flow rate in the pressure cave is, and it is easy to cause sediment deposition; The greater the opening of the gate is, the more favorable the overall operation of the tunnel is. The research results have guiding significance for the optimization of the operating opening of the hydraulic tunnel gate and the anti-wear repair of the gate bottom sill.
| 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 |