Numerical and experimental investigations of closure of an emergency bulkhead gate
2015 (English)Conference paper (Refereed)
The design of hydraulic gates is crucial for safely operating a hydropower dam. An emergency gate is especially important as it protects structures or turbines situated downstream. In this study, both numerical and experimental investigations were performed of an emergency bulkhead gate closure. The gate has a size of 4.978 m (w) by 6.166 m (h) and a thickness of 0.94 m and is subjected to a water head of 80.8 m and a flow rate of 207 m3/s. In an earlier stage, a 1:18 scale model was constructed. The CFD simulations were then made using the RNG k−ε turbulence model and Volume of Fluid method (VOF). A moving dynamic mesh was adopted to follow the gate movement. The goal was to extract the pressure distribution around the gate, subsequently to obtain the hydrodynamic forces acting on the gate and to analyze the flow pattern. The CFD model was validated against the experimental data. The closing speed of the gate and its bottom edge angle were examined in order to reduce the down-pull force and to avoid undesirable flow phenomena. It was found that to lower the gate speed to 8.1 m/min would have a positive effect. The gate would close slower, with reduced forces and less induced vibrations. To change the gate bottom edge angle from 9° to 20-30°, would considerably reduce gate vibrations.
Place, publisher, year, edition, pages
IdentifiersURN: urn:nbn:se:kth:diva-179749OAI: oai:DiVA.org:kth-179749DiVA: diva2:889222
25th ICOLD Congress, June 2015, Stavanger, Norway
QS 20162015-12-222015-12-222016-01-04Bibliographically approved