When the pipeline truck moves smoothly, the velocity distribution characteristics of the water flow in the annular gap are related to the interaction between the pipeline truck and the water flow, which will also affect the motion characteristics of the pipeline truck and the hydraulic characteristics in the pipeline. This paper studied the overall and local distribution characteristics of the water flow velocity in the annular gap when the pipeline car moves smoothly by means of physical experiments and theoretical analysis. The relationship between the distribution characteristics of the water flow velocity in the annular gap of the pipeline car with different diameters and the transmission efficiency were compared. The results show that when the pipeline car moves smoothly, the velocity at the inlet section of the annulus is the largest, followed by the middle section of the car, and the velocity at the rear section of the car is the smallest; The flow velocity near the wall of the pipeline truck changes greatly along the way, and the flow velocity near the pipe wall changes less along the process; The distribution of the water flow velocity in the annular gap of the pipeline car with different diameters affects the transportation efficiency of the pipeline car. When the ratio of the water flow velocity in the annular gap to the water flow velocity in the pipeline is close to 1, the transportation efficiency of the pipeline car is the highest.
| 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 |