Numerical simulation on rectifying flow in intake system of a pumping station connected with headrace pipe

Pipes are usually adopted in those conditions for which the pump house is far from water source. As for fore-bay, flow of headrace pipe can be considered as jet-flow. Jet-flow has a high velocity, and creates large pressure gradient between jet-flow and near wall flow, which contributes to large scale circulation. In that circumstance, a single rectification measure cannot effectively improve the flow pattern of intake flow field. For large scale pumping station, there is enough space to arrange complex anti-vortex devices. Thus, a new type of combined diversion piers composed of double-I type pier, three-I type pier and cross anti-vortex baffle was proposed. In order to investigate the influences of combined division piers on flow pattern, four cases with different geometry and location parameters are designed. The results of numerical simulation and site tests show that the combined diversion piers could effectively improve the intake flow field of pumping station with headrace pipe. As for pumping station with headrace pipe, the distance between inlet section of fore-bay and leading edge of double-I type diversion pier should be 0.25 L -0.53 L (where L is the length of fore-bay). The distance between inlet section of fore-bay and trailing edge of double-I type diversion pier should be 0.5 L -0.73 L . The total length of double-I type pier should be 0.2 L -0.25 L .