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

Abstract

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. hydraulic engineering, 3-D flow field, numerical simulation, plunge pool, submerged jets

Numerical Study of the Aerodynamic Loads on Offshore Wind Turbines under Typhoon with Full Wind Direction

“…The RNG k-ε turbulence model was adopted, which is widely used and has more data accumulation and considerable precision [29,35,36]. Additionally, the enhanced wall function was utilized to obtain the flow field characteristics in the wall region of the turbulent boundary layer.…”

Characteristics of vortex structure in multi-horizontal submerged jets stilling basin

“…They found that the scale of the model had only a slight effect on the time-averaged hydraulic characteristics, which indicates that the results for the time-averaged hydraulic characteristics for a normal model are reliable. Numerical simulations by Chen et al (2010b), Deng et al (2008), Gao et al (2006), Li et al (2004Li et al ( , 2006aLi et al ( , 2006bLi et al ( , 2006c and Yang et al (2004Yang et al ( , 2006 of the velocity field in a stilling basin of MHSJs showed that there was no perforative vertical whirl in the stilling basin and that the vortex would dissociate on the slab instead of remaining fixed at a particular location.…”

“…Zhang et al (2005aZhang et al ( , 2005b derived theoretical equations for the sequent depth ratio and the energy dissipation ratio for submerged hydraulic jumps in a stilling basin of MHSJs. Deng et al (2008) performed a series of experimental studies on the characteristics of MHSJs. They found that the flow patterns were quite stable in the presence of changes in tailwater level, provided that there was a large aspect ratio in the stilling basin.…”

Experimental Optimization of Gate-Opening Modes to Minimize Near-Field Vibrations in Hydropower Stations

“…MHSJ have been studied and improved by many researchers in recent years [8][9][10][11][12][13][14][15][16][17]. It has been demonstrated that MSHJ possesses three main advantages when compared with the hydraulic jump, which is the traditional energy dissipater: (1) lower atomization; (2) a higher rate of energy dissipation; (3) more flexibility of gate-opening modes [12][13][14]. Thus, it seems feasible to implement MHSJ to tackle the problem of energy dissipation within large hydropower stations that are typically characterized by higher water heads and larger flowrates.…”

“…Thus, it seems feasible to implement MHSJ to tackle the problem of energy dissipation within large hydropower stations that are typically characterized by higher water heads and larger flowrates. The adoption of MHSJ was tested by Deng et al [12] and successfully applied as energy dissipation in large-scale hydropower stations [14].…”