Three-Dimensional Flow of a Vortex Drop Shaft Spillway with an Elliptical Tangential Inlet

Abstract

Vortex drop shaft (VDS) spillways are eco-friendly hydraulic structures used for safely releasing flood. However, due to the complexity of the three-dimensional rotational flow and the lack of suitable measuring devices, current experimental work cannot interpret the flow behavior reliably inside the VDS spillway, consequently experimental and CFD study on a VDS spillway with an elliptical tangential inlet was conducted to further discern the interior three-dimensional flow behavior. Hydraulic characteristics such as wall pressure, swirl angle, annular hydraulic height and Froude number of the tapering section are experimentally obtained and acceptably agreed with the numerical prediction. Results indicated that the relative dimensionless maximum height of the standing wave falls off nearly linearly with the increasing Froude number. Nonlinear regression was established to give an estimation of the minimum air-core rate. The normalized height of the hydraulic jump depends on the flow phenomena of pressure slope. Simulated results sufficiently reveal the three-dimensional velocity field (resultant velocity, axial velocity, tangential velocity and radial velocity) with obvious regional and cross-sectional variations inside the vortex drop shaft. It is found that cross-sectional tangential velocity varies, resembling the near-cavity forced vortex and near-wall free vortex behavior. Analytic calculations for the cross-sectional pressure were developed and correlated well with simulated results.

Chaotic Characteristic Analysis of Spillway Radial Gate Vibration under Discharge Excitation

“…The common threshold function is divided into soft and hard threshold functions [25,26], which are given in Equations ( 19) and (20), respectively:…”

“…Therefore, it was important to determine the velocity field distribution in order to analyze the vibration characteristics of the spillway radial gate, as no comprehensive and continuous flow field information could be obtained due to the limited nature of the prototype test. Numerical simulations that adopted the RNG k-ε turbulent model were performed using Ansys Fluent 2021R1 software to simulate the flow field [20,21], which served as inputs for the subsequent analysis of the gate vibration in this paper. Its grid diagram is shown in Figure 4, with a total grid of 2.94 million; Figure 5 shows the schematic diagram of the open flow pattern.…”

“…Therefore, it was impo velocity field distribution in order to analyze the vibration charact radial gate, as no comprehensive and continuous flow field informa due to the limited nature of the prototype test. Numerical simula RNG k-ε turbulent model were performed using Ansys Fluent 202 late the flow field [20,21], which served as inputs for the subseque vibration in this paper. Its grid diagram is shown in Figure 4, wi million; Figure 5 shows the schematic diagram of the open flow pa flow field derived from the numerical simulations, the flow pattern out of the bottom edge of the gate was relatively smooth, which p outflow pattern.…”

Editorial—Physical Modelling in Hydraulics Engineering

“…The aim of this Special Issue is thus to publish the latest advances and developments concerning physical modeling in hydraulics engineering. This Special Issue contains contributions to the physical and numerical modeling of hydraulics structures, such as dam stilling basing [5][6][7], stepped spillways [8], free falling jets [9] and vortex shaft drops [10]. The development of traditional [11] and novel [12,13] modelling approaches in river engineering are also covered in the Special Issue.…”

“…The article "Three-Dimensional Flow of a Vortex Drop Shaft Spillway with an Elliptical Tangential Inlet" [10] analyzes hydraulic characteristics of vortex drop shaft (VSD) spillways using physical model experiments and a computer fluid dynamics (CFD) model. Considering that the eco-friendly VDS has become an important research hotspot in the field of flood discharge and energy dissipation, the current work can provide useful insights for future research and application of similar engineering approaches.…”