A new type of plunge pool-Multi-horizontal submerged jets

Based on the understanding of the mechanism of energy dissipation, a new type of plunge pool is presented with the advantages of high rate of energy dissipation, low impact pressure, and small close-to-bed velocity on the soleplate of the plunge pool. The first advantage owes to enlarged shearing energy dissipation areas in the plunge pool, while the other two are caused by the jet that enters in a nearly horizontal level to keep the soleplate from being scoured directly. All of the above arrangements make this new type of energy dissipator distinct from the underflow energy dissipation. Through experiments on the physical model, the authors found that the water flow maintained stable and submerged in horizontal direction when the flow was narrow in horizontal but thick in vertical direction. However, the wide flat nappe was ready to submerge or float as the downstream water level rised or dropped. The entire flow fields of multi-horizontal submerged jets into plunge pool were also numerically simulated. The numerical results of water surface curve, close-to-bed velocity and floor pressure agree well with the experimental data. The flow pattern in the plunge pool was analyzed after combining the laboratory data and numerical simulation.