A new type of leak-floor flip bucket

Flip buckets are commonly used to discharge flow away from a hydraulic structure into the downstream to dissipate energy. A new leak-floor flip bucket is presented, making the ski-jump water jet a typical long-narrow nappe. Based on the model ex- periments and numerical simulation, the flow pattern, formation process and mechanism of the leak-floor flip bucket are stud- ied. The results show that cross section flow shape develops from the ＂Y-type＂ to ＂｜-type＂, and this is because the natural pressure difference is generated when water flows through the leak-floor area and moves transversely from both sides to the center. Different from the slit-type flip bucket with sidewall contraction, the leak-floor flit bucket makes the water jet narrow and long without high pressure on the side walls of the flip bucket. Under the same jet length condition, the maximum sidewall pressure of the slit-type is 4.67 times that of the leak-floor flip bucket. The effects of flow discharge on the jet length are less significant for the leak-floor bucket than for the slit-type bucket.