181 / 2024-02-27 08:47:21

Study on Wave Absorbing Measures of High Froude Number Connecting Pool in Tunnel of Water Diversion Project

Water diversion project；Connecting pool in tunnel；Wave-absorbing beams；high Froud number; Water disaster

Based on the hydraulic model with a scale of 1:15 , several wave absorbing schemes were studied to solve the problems that the connecting pool in diversion tunnel project had higher wave under the condition of high Froud's number flow, resulting in insufficient roof margin for long-distance open flow tunnels or the need to increase the height of the tunnel. The results show that: (1) The single-layer wave beam is not suitable for the working condition of high head amplitude, and the vertical beams has the worst wave dissipation and water resistance, which has the greatest impact on the leading edge of the jump head and the instantaneous maximum water depth in the pool; the narrow spacing beams has a good effect on the wave dissipation, and the wave of the open flow tunnel is reduced by 2/3 after the optimized layout scheme, and the wave amplitude rate is 0.08-0.11, the wave dissipation effect is better. (2) The wave-absorbing beams of the connecting pool has no effect on the flow conveyance capacity of the pressurized tunnel, and has little effect on ŋ_p in the pool. (3) Negative pressure occurs in the local areas of the weir surface curve section of the bottom plate and the diffusion section of the side wall of the optimization scheme when the high reservoir water level is running, the cavitation number of the flow is small, and the cavitation problem is not produced, the maximum RMS value doesn’t exceed 1.0×9.81kPa. The maximum RMS value of the wave-absorbing beams doesn’t exceed 0.52×9.81kPa, and the main fluctuation frequency is 0.5~1.2Hz.