旋涡隧道溢洪道及液压操作条件外文翻译-液压系统(编辑修改稿)

旋涡隧道溢洪道及液压操作条件外文翻译-液压系统(编辑修改稿)内容摘要：

ower ponds from the external atmosphere and to reduce the air pressure in these regions through creation of a vacuum in accordance with the geometric scale of the model. Hydraulic Conditions throughout the Spillway Segment. The hydraulic conditions of operation of vortex spillways differ substantially from the corresponding conditions for spillways constructed in the traditional configuration. Let us consider these differences on the basis of the results of laboratory studies of the operational spillways of the Rogunskii hydroelectric plant (which includes an energy dissipation chamber) and the spillway of the Teri hydraulic works (which operates with smooth dissipation of energy throughout the length of the tunnel).The initial design of the Rogunskii hydroelectric plant called for a chute as the terminus structure of the operational spillway。 it was intended that the flow rate at the end of the chute was to reach 60 m/sec. Understandably, flow rates that are this high entail adoption of special measures to protect the streamlined surfaces of the spillway from cavitation damage and the stream course from dangerous degradation. To meet this need, the Tashkent Hydroelectric Authority, working with the Division of Hydrodynamic Research (now the Central Hydraulic Institute, Society of the Scientific Research Institute on the Economics of Construction), developed several alternative versions of spillway designs intended to dissipate a significant portion of the energy of the flow within the spillway and to substantially reduce the flow rate in the tailrace tunnel and at the point where the flow is discharged into the stream course. In one of the versions that were considered, the bend in the turning segment that is part of the traditional configuration of a shaft spillway was replaced by a tangential flow vortex generator. Similarly. vortextype flow is created throughout the entire length of the tailrace segment. Hydraulic studies were performed on a model that simulated a shaft spillway at a scale of 1:50 and consisted of a shaft measuring 13 m in diameter and 148 m in height, a tangential vortex generating device, and a tailrace tunnel. The studies that were performed showed that in the shaft which delivers water to the flow rotation node, an intermediate water level is maintained when the flow rate is less than the design rate. This bench mark depends on the magnitude of the escapage discharge and the resistance of the spillway segment situated at a lower level . In the constructions that have been considered here, maximum (design) flow rates through the shaft are achieved when the shaft is flooded and there is no access to the air. In the model nearly 5 plete entrapment of air from the water surface occurred with intermediate water levels in the shaft。 moreover, the lower the level of the water surface, the more the air restrained the water flow and transformed the flow into a rotation node (Fig. 7). Stable vortextype flow with a peripheral water ring and internal gasvapor core is formed beyond the tangential vortex generator. Due to asymmetric delivery of water into the vortex generator in the initial segments, the core of the flow is noncircular and situated away from the center of the cross section. Throughout the length of the initial cylindrical segment of the conduit, the gasvapor core possesses a wavelike curved axis which coincides with the axis of the tunnel even as close as 10dx from the axis of the shaft. As nonaerated flow enters the tailrace conduit through the rotation node, a vacuumgauge pressure is established in the gasvapor core, and in the case of highly aerated flow, gauge pressure, The reduction in pressure in the gasvapor core is associated with the effect of centrifugal forces in vortextype flow, while an increase in pressure is associated with nearly plete release of air from the aerated flow into the core induced by the transport of air bubbles from the periphery to the center under the effect of the pressure gradient. For a tailrace conduit with cylindrical initia。