| Most of the large hydropower projects were located in the mountain valley area of northwestern and southwestern China. They have high water head, large amount of drainage, so water of dam body can’t bear all the work; especially the construction of concrete face rock fill dam, the flood discharge tunnel should be built on the bank. As the core part of power station hub engineering drainage construction technology in the eclipse energy dissipation facilities, the traditional energy dissipation had three shortcomings: inefficient, high velocity, and serious export atomization. Given the influence on ecological environment of current hydropower project had become a index when measure the engineering feasibility, one of the trend is the task of energy dissipation of drainage buildings in the extrapolation from hole to hole, in addition to meet the basic request of the discharge it should also take the anti-cavitations, protect the ecological and reduce investment into account. Environment friendly vortex energy dissipation work inside the hole was an important part of the popular research fields in flood discharge energy dissipation and direction. This article studies a new type of vortex ring weir shaft spillway tunnel belongs to a kind of typical energy dissipation, it is based on traditional ring weir shaft spillway tunnel, but in the whole tunnel, the flow regime on the corrosion mechanism and energy dissipation, completely is a different approach. As a new type of decorate a form of energy dissipation, the hydraulics characteristics was not very clear, the traditional model experiment method is still difficult to reveal the complex flow characteristics, so it is necessary to carry out the numerical simulation of the flow under the new size and characteristic analysis, the results of further popularization and application has profound significance.Relying on the pumped storage power station under the reservoir spillway tunnel engineering on the Guangdong Qingyuan, computational fluid dynamics, using fluent software and based on the RNG k-ε mathematical model and combining the VOF(Volume Of Fluid) method, the vortex ring Of weir shaft spillway tunnel inlet, flood discharge tunnel with vertical flow and export the complex flow of 3-d numerical simulation. The main research content includes: 1) the vortex ring weir shaft spillway tunnel flow numerical simulation and characteristics analysis; 2) diving on the hydraulic mechanism of spin pier, arrangement principle and flow characteristics calculation; 3) computing annular weir shaft cavity synthesis of spiral flow rate and pressure; 4) in the aeration hole pressure energy dissipation of characteristics, structural characteristics, etcSimulation results show that the model and algorithm can be well simulated with high turbulence, the strong centrifugal force effect and strong rotation with free surface of circular shaft spiral movement of weir. Simulation of the new shape vortex cavity flow, free water surface, synthetic velocity, pressure, turbulence kinetic energy and dissipation rate and the total energy dissipation distribution of hydraulic elements were in good agreement with model test results, and further reveals the self-adjusting diving spin vortex motion mechanism of the pier, perfect the new vortex ring weir shaft of the tunnel, the design theory and the calculation method of hydraulic characteristics, for the future of this new type of energy dissipation work offer a scientific basis for further popularization and application... |
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