Numerical Simulation of Hydraulic Transients in Long Corridor Surge Tank

2010 ◽  
Author(s):  
Xiaodong Yu ◽  
Jian Zhang ◽  
Arash Hazrati ◽  
Sheng Chen
Keyword(s):  
Numerical Simulation ◽  
Numerical Model ◽  
Nonlinear Partial Differential Equations ◽  
Scientific Basis ◽  
Hydropower Station ◽  
Surge Tank ◽  
Hydraulic Transients ◽  
Tank Model ◽  
New Model ◽  
Fluid Transients

A numerical model of fluid transients in long corridor surge tank, based on the equations of Saint-Venant, is developed. The implicit method of Preissman, with appropriate boundary conditions, is used to solve these two nonlinear partial differential equations. The hydraulic transients with new model and normal surge tank model are simulated and compared with model experiments. It is clarified that the new numerical model can simulate the changes of water level in long corridor surge tank and pressure along penstock realistically. The new model provides scientific basis for studying hydraulic transients of hydropower station with long corridor surge tank.

Influence of Successive Load Rejections on Water Hammer Pressure of Spiral Case in Long Diversion-Type Hydropower Station

2014 ◽  
Vol 607 ◽  
pp. 551-555 ◽  
Author(s):  
Xiao Dong Yu ◽  
Jian Zhang ◽  
Cheng Yu Fan
Keyword(s):  
Numerical Model ◽  
Method Of Characteristics ◽  
Water Hammer ◽  
Hydropower Station ◽  
Maximum Pressure ◽  
Surge Tank ◽  
Hydraulic Transients ◽  
Rotating Speed ◽  
Spiral Case

Based on the theory of hydraulic transients and method of characteristics (MOC), the numerical model of hydraulic transients in water way system was established using the data of a practical hydropower station, and the probable transients were simulated. The influence of successive load rejection conditions on water hammer pressure of spiral case was analyzed. Compared with simultaneous load rejection, successive load rejection can make maximum pressure in spiral case and maximum rotating speed of runner more serious if the bifurcated pipe converging under surge tank in diversion-type hydropower station.

scholarly journals Hydraulic Transients in the Long Diversion-Type Hydropower Station with a Complex Differential Surge Tank

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Xiaodong Yu ◽  
Jian Zhang ◽  
Ling Zhou
Keyword(s):  
Pressure Difference ◽  
Mathematic Model ◽  
Hydropower Station ◽  
Maximum Pressure ◽  
Surge Tank ◽  
Hydraulic Transients ◽  
Rotating Speed ◽  
Spiral Case ◽  
Two Sides ◽  
Breast Wall

Based on the theory of hydraulic transients and the method of characteristics (MOC), a mathematic model of the differential surge tank with pressure-reduction orifices (PROs) and overflow weirs for transient calculation is proposed. The numerical model of hydraulic transients is established using the data of a practical hydropower station; and the probable transients are simulated. The results show that successive load rejection is critical for calculating the maximum pressure in spiral case and the maximum rotating speed of runner when the bifurcated pipe is converging under the surge tank in a diversion-type hydropower station; the pressure difference between two sides of breast wall is large during transient conditions, and it would be more serious when simultaneous load rejections happen after load acceptance; the reasonable arrangement of PROs on breast wall can effectively decrease the pressure difference.

Numerical Simulation of Multidirectional Waves With Full-Spectrum Using DualSPHysics

2019 ◽  
Author(s):  
Taiga Kanehira ◽  
Hidemi Mutsuda ◽  
Samuel Draycott ◽  
David M. Ingram ◽  
Yasuaki Doi
Keyword(s):  
Numerical Simulation ◽  
Numerical Model ◽  
Smoothed Particle Hydrodynamics ◽  
Full Spectrum ◽  
Tank Model ◽  
Type Wave ◽  
Wave Basin ◽  
Particle Hydrodynamics ◽  
Spreading Function ◽  
Smoothed Particle

Abstract The numerical model for circular wave basin were developed using DualSPHysics based on Smoothed Particle Hydrodynamics to generate short-crested wave. The recreation of short-crested wave was achieved using Pierson Moskowitz spectrum and cosin2s spreading function with spreading value s. It is found that this numerical tank model could successfully reproduced not only long-crested but short-crested waves using 168 hinged-flap type wave makers.

Critical superposition instant of surge waves in surge tank with long headrace tunnel

2011 ◽  
Vol 38 (3) ◽  
pp. 331-337 ◽  
Author(s):  
XiaoDong Yu ◽  
Jian Zhang ◽  
Arash Hazrati
Keyword(s):  
Numerical Simulation ◽  
Flow Rate ◽  
Analytical Formula ◽  
Hydropower Station ◽  
Surge Tank ◽  
Initial Water ◽  
Initial Flow ◽  
Headrace Tunnel ◽  
Fundamental Equations ◽  
Computational Basis

Superposed mass oscillation that often occurs in a throttled surge tank with a long headrace tunnel is studied. The instant of the worst superposition of mass oscillation in a surge tank is analysed. The analytical formula predicting the worst superposition instant is derived exactly and verified (1) with a numerical solution to the fundamental equations for the surge tank and (2) with a numerical simulation of hydraulic transients in an actual hydropower station. It is shown that the superposed oscillation provides the highest upsurge at the instant that the initial flow rate in the headrace tunnel and initial water level in the surge tank satisfy the judgement formula. The conclusion provides a theoretical and computational basis for the numerical simulation of maximum upsurge in a surge tank.

scholarly journals Blowing and drifting snow in Alpine terrain: numerical simulation and related field measurements

1998 ◽  
Vol 26 ◽  
pp. 174-178 ◽  
Author(s):  
Peter Gauer
Keyword(s):  
Numerical Simulation ◽  
Numerical Model ◽  
Three Dimensional ◽  
Field Measurements ◽  
Blowing Snow ◽  
Related Field ◽  
Drifting Snow ◽  
Physically Based ◽  
Snow Transport

A physically based numerical model of drifting and blowing snow in three-dimensional terrain is developed. The model includes snow transport by saltation and suspension. As an example, a numerical simulation for an Alpine ridge is presented and compared with field measurements.

scholarly journals Hydraulic Transients in Viscoelastic Pipeline System with Sudden Cross-Section Changes

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4071
Author(s):  
Michał Kubrak ◽  
Agnieszka Malesińska ◽  
Apoloniusz Kodura ◽  
Kamil Urbanowicz ◽  
Michał Stosiak
Keyword(s):  
Numerical Model ◽  
Cross Section ◽  
Laboratory Data ◽  
Experimental Studies ◽  
Distribution Networks ◽  
Water Hammer ◽  
Fluid Distribution ◽  
Pipeline System ◽  
Hydraulic Transients ◽  
Single Pipe

It is well known that the water hammer phenomenon can lead to pipeline system failures. For this reason, there is an increased need for simulation of hydraulic transients. High-density polyethylene (HDPE) pipes are commonly used in various pressurised pipeline systems. Most studies have only focused on water hammer events in a single pipe. However, typical fluid distribution networks are composed of serially connected pipes with various inner diameters. The present paper aims to investigate the influence of sudden cross-section changes in an HDPE pipeline system on pressure oscillations during the water hammer phenomenon. Numerical and experimental studies have been conducted. In order to include the viscoelastic behaviour of the HDPE pipe wall, the generalised Kelvin–Voigt model was introduced into the continuity equation. Transient equations were numerically solved using the explicit MacCormack method. A numerical model that involves assigning two values of flow velocity to the connection node was used. The aim of the conducted experiments was to record pressure changes downstream of the pipeline system during valve-induced water hammer. In order to validate the numerical model, the simulation results were compared with experimental data. A satisfactory compliance between the results of the numerical calculations and laboratory data was obtained.

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