旋渦隧道溢洪道及液壓操作條件外文翻譯-液壓系統(tǒng)-文庫(kù)吧在線文庫(kù)
【正文】 價(jià)設(shè)計(jì)溢洪道 的尺寸 。終端部分尾水洞渦流溢洪道可以構(gòu)造的形式， 一個(gè)挑斗，消力池，或特殊結(jié)構(gòu)取決于流量的出口從隧道和條件的下游航道。有鑒于此，我們希望 引起 讀者的注意，基本上是新的 概念 （即，在配置和操作條件），利用旋渦流溢洪道。mamskii hydraulic works, Are q = 。s attention to essentially novel (., in terms of configuration and operating conditions) vortex spillways which utilize vortextype flows. On the one hand, these types of spillways make possible largescale dissipation of the kiic energy of the flow on the initial leg of the tailrace segment, and, as aconsequence, flow rates of slightly vortextype and axial flows through the subsequent legs that do not produce cavitation damage. On the other hand, the dangerous effect of high flow rates on the streamlined surface decreases over the length of the initial tailrace leg as a consequence of the increased pressure on the wall caused by the effect of centrifugal forces. A number of structural studies of tunnel spillways for hydraulic works such as the Rogunskii, Teri, Tel39。 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 initial segment, the free area downstream increases from in the section at a distance from the axis of the shaft to in the section at a distance , while the angle of flow rotation and the axial and circumferential flow rates all decrease. In the case of a conical initial segment, the relative area of the gasvapor core decreases from to over the length of the conical segment, while the angle of flow rotation decreases to between onehalf and twothirds its initial value over this segment. A characteristic feature of the construction that is being proposed in the present article is the presence of an energy dissipation chamber in which vortextype flow experiences an abrupt expansion and is rapidly transformed into axial flow if the discharge of flow from the tailrace tunnel is directed into the of the centrifugal acceleration to the free fall acceleration is an essential condition for breakdown of thevortex structure of the flow in the tunnel. Once equality is achieved, the mass of water traveling along the roof of the tunnel caves in, and mixes easily with the air in the flow core. The transformation of vortexlike flow into axial flow that occurs here is acpanied by significant dissipation of energy. The rate of energy dissipation differs between the two versions that are being considered here (Fig. 8). In the case of a cylindrical initial segment, energy dissipation 6 occurs smoothly, with only 60% of the initial energy of the flow dissipating over a distance of 15dw (Fig. 8a). In a system with a conical vortex generator and energy dissipation chamber behind the generator, 86% of the initial energy of the flow dissipates as it travels through this segment, CONCLUSIONS Application of the constructions ot vortex tunnel spillways that we have considered enable us to ensure effective dissipation of the excess kiic energy and ove
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