scholarly journals 2D numerical modelling of dam break- applying for Namchien dam in Vietnam

2019 ◽  
Vol 8 (9) ◽  
pp. 711-716
Keyword(s):  
Dam Break ◽  
Arch Dam ◽  
Roughness Coefficient ◽  
Proposed Model ◽  
Nonlinear Shallow Water Equations ◽  
Time Histories ◽  
Friction Term ◽  
Dam Break Flow ◽  
High Roughness ◽  
Volume Method

The paper is dedicated to study a numerical model simulating dam-break based on two dimensional nonlinear shallow water equations (2D-NSWE). Finite Volume Method-Godunov type is applied to discretize this equation. Roe scheme is utilized to approximate Riemann problem, meanwhile method of flux difference splitting is implemented to construct numerical solvers of SWE. Besides, the semi implicit scheme is also invoked to solve friction term in case of high roughness coefficient. The proposed model is verified through a comparison between computed results and empirical data of two reference tests. A dam break flow over floodable area with different roughness coefficients is also researched. A total collapsed dam scenario of an arch dam-Nam Chien in Vietnam is simulated by the proposed model. Several hydraulic characteristics such as flood extent, arrival time and time histories of water depth at different gauges are estimated with different grid sizes.

Numerical Simulation of 2D Dam-Break Flow in a Vertical Plane

2011 ◽  
Vol 130-134 ◽  
pp. 3620-3623
Author(s):  
Ming Qin Liu ◽  
Y.L. Liu
Keyword(s):  
Free Surface ◽  
Flow Model ◽  
Vertical Plane ◽  
Surface Profile ◽  
Dam Break ◽  
Governing Equations ◽  
Proposed Model ◽  
2D Flow ◽  
Dam Break Flow ◽  
Volume Method

This paper was concerned with a vertical two-dimensional (2D) flow model with free surface. The water governing equations were discretized with finite difference method. The function of volume method was employed to track the moving free surface. The model was used to predict the characteristics of dam-break flow in a 2D vertical plane. The surface profile and time averaged velocity were calculated, which shows the proposed model can be capable of capturing sharp water and gas interface configuration as time elapses.

scholarly journals 1D and 2D Numerical Modeling for Solving Dam-Break Flow Problems Using Finite Volume Method

2012 ◽  
Vol 2012 ◽  
pp. 1-14 ◽  
Author(s):  
Szu-Hsien Peng
Keyword(s):  
Shallow Water ◽  
Finite Volume Method ◽  
Finite Volume ◽  
Shallow Water Equation ◽  
Dam Break ◽  
Flume Experiments ◽  
One Dimensional ◽  
Dam Break Flow ◽  
The One ◽  
Volume Method

The purpose of this study is to model the flow movement in an idealized dam-break configuration. One-dimensional and two-dimensional motion of a shallow flow over a rigid inclined bed is considered. The resulting shallow water equations are solved by finite volumes using the Roe and HLL schemes. At first, the one-dimensional model is considered in the development process. With conservative finite volume method, splitting is applied to manage the combination of hyperbolic term and source term of the shallow water equation and then to promote 1D to 2D. The simulations are validated by the comparison with flume experiments. Unsteady dam-break flow movement is found to be reasonably well captured by the model. The proposed concept could be further developed to the numerical calculation of non-Newtonian fluid or multilayers fluid flow.

scholarly journals Parallel Algorithms of Well-Balanced and Weighted Average Flux for Shallow Water Model Using CUDA

2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Nugool Sataporn ◽  
Worasait Suwannik ◽  
Montri Maleewong
Keyword(s):  
Shallow Water ◽  
Weighted Average ◽  
Dam Break ◽  
Global Memory ◽  
Water Model ◽  
Shallow Water Model ◽  
Real World Problem ◽  
Dry Conditions ◽  
Dam Break Flow ◽  
Volume Method

Compute Unified Device Architecture (CUDA) implementations are presented of a well-balanced finite volume method for solving a shallow water model. The CUDA platform allows programs to run parallel on GPU. Four versions of the CUDA algorithm are presented in addition to a CPU implementation. Each version is improved from the previous one. We present the following techniques for optimizing a CUDA program: limiting register usage, changing the global memory access pattern, and using loop unroll. The accuracy of all programs is investigated in 3 test cases: a circular dam break on a dry bed, a circular dam break on a wet bed, and a dam break flow over three humps. The last parallel version shows 3.84x speedup over the first CUDA implementation. We use our program to simulate a real-world problem based on an assumed partial breakage of the Srinakarin Dam located in Kanchanaburi province, Thailand. The simulation shows that the strong interaction between massive water flows and bottom elevations under wet and dry conditions is well captured by the well-balanced scheme, while the optimized parallel program produces a 57.32x speedup over the serial version.

Coupled dam-break flow and bed load modelling using HLLC-WAF scheme

2015 ◽  
Vol 72 (7) ◽  
pp. 1155-1167 ◽  
Author(s):  
Alireza Hosseinzadeh-Tabrizi ◽  
Mahnaz Ghaeini-Hessaroeyeh
Keyword(s):  
Experimental Data ◽  
Weighted Average ◽  
Dam Break ◽  
Triangular Grid ◽  
Governing Equations ◽  
Mobile Bed ◽  
Dam Break Flow ◽  
Average Flux ◽  
Comparison Of The Results ◽  
Volume Method

A two-dimensional numerical model predicting flow over a mobile bed has been developed. Governing equations consist of the shallow water equations and the Exner equation. The finite volume method on an unstructured triangular grid was deployed to discretize the governing equations. The local Riemann problem is solved by the Harten, Lax and van Leer–contact (HLLC) method in the interface of the cells and the equations are solved using a fully coupled method. Then the flux modelling has been deployed by the total variation diminishing (TVD) version of the weighted average flux (WAF) scheme. The model was verified by comparison of the results and available experimental data for dam-break flow, in a laboratory test, via a channel with sudden enlargement and erodible bed conditions. Comparison of these two sets of results shows that increasing the accuracy of flux modelling caused the model results to have a reasonable agreement with the experimental data.

Numerical Simulation of 2D Circular Dam-Break Flows with WENO Schemes

2012 ◽  
Vol 468-471 ◽  
pp. 2201-2205
Author(s):  
G.C. Sun ◽  
Wen Li Wei ◽  
Y.L. Liu ◽  
Xi Wang ◽  
Ming Qin Liu
Keyword(s):  
River Flow ◽  
Time Discretization ◽  
Flow Property ◽  
Dam Break ◽  
Weno Scheme ◽  
Tvd Scheme ◽  
Flow Velocity Field ◽  
Field Distributions ◽  
Proposed Model ◽  
Volume Method

This paper is concerned with a mathematical model for simulating hydrodynamics of 2D circular dam-break flows with the WENO scheme and the Finite Volume Method. The time discretization uses the Runge-Kutta TVD scheme. By using the proposed model, we calculated the flow property of circular dam-break, and obtained the flow velocity field distributions. The calculated results show that the WENO scheme has higher accuracy and better stability, and has the ability to automatically capture shock waves, and may suppress the oscillations of numerical solution. This model can effectively simulate the hydrodynamics of 2D river flow with irregular boundaries.

scholarly journals Computation of Hydraulic Characteristics of Flood Flow Downstream from the Reservoir with Dam Safety Scenarios in North Vietnam

10.29007/7gg6 ◽  
2018 ◽  
Author(s):  
Thu Hien Thi Le ◽  
Viet Hung Ho
Keyword(s):  
Numerical Model ◽  
Water Resource Management ◽  
Dam Break ◽  
Arch Dam ◽  
Dam Safety ◽  
Hydraulic Characteristics ◽  
Maximum Water Level ◽  
Indispensable Tool ◽  
North Vietnam ◽  
Volume Method

Using a reservoir is an effective solution to prevent lowland flooding and mitigate socio-economic damages. However, due to the high density of river network and the presence of reservoirs, dam safety assurance is becoming one of the most important mission in water resource management in Vietnam. Hydraulic characteristics of dam-break wave are necessary information to generate early warning plans for downstream area of reservoir. To aim this purpose, the Finite Volume Method with Godunov-type is considered to solve two-dimensional shallow water equations and develop a numerical model. In this study, the numerical model for dam-break simulation is suggested and verified through a comparison between calculated results and observed data of two reference tests. Very good agreement shows the effectiveness and accuracy of the proposed model. The Nam Chien reservoir in Vietnam has been chosen and the numerical model is applied to simulate flooding wave for the scenario of arch dam collapse. Alternative solutions are produced, such as: water depth, discharge hydrographs, arrival time, time to reach maximum water level; flooding map. The simulated result implies that this model is an indispensable tool for simulating dam-break scenarios.

Uncertainty in Dam Break Flow Simulation

1989 ◽  
Vol 20 (4-5) ◽  
pp. 249-256 ◽  
Author(s):  
Chen Shan Kung
Keyword(s):  
Unsteady Flow ◽  
Flow Model ◽  
Flow Simulation ◽  
Dam Break ◽  
Roughness Coefficient ◽  
Natural Conditions ◽  
One Dimensional ◽  
Dam Break Flow ◽  
Manning’S Coefficient ◽  
Dam Breaking

The flow caused by a dam breaking across its entire length can be approximated by a one-dimensional, unsteady flow model in form of the St. Venant equations. In this model, the flow is governed by the river geometry and the river roughness, which is quantified by Manning's coefficient. The roughness characteristics are generally difficult to estimate under natural conditions. Thus, the estimates of the Manning's coefficient will in general be subject to uncertainty. In this paper, the uncertainty in the discharge and depth hydrographs due to the uncertainty in estimating the roughness characteristics of a river, is investigated. A specific case of the Noppikoski dam in Sweden that failed in 1985 is used to illustrate the sensitivity of the flow simulation on the roughness coefficient. The analysis shows that the uncertainty in the dam break flow simulation due to the uncertainty in estimating Manning's coefficient, is significant. The uncertainty is larger at greater distances from the dam, and is greater for the discharge hydrograph than for the depth hydrograph.

scholarly journals Interactions Study of Hydrodynamic-Morphology-Vegetation for Dam-Break Flows

2016 ◽  
Vol 2016 ◽  
pp. 1-12
Author(s):  
Mingliang Zhang ◽  
Yuanyuan Xu ◽  
Jin Li ◽  
Huiting Qiao ◽  
Hongxing Zhang
Keyword(s):  
Numerical Model ◽  
Morphological Changes ◽  
Flow Region ◽  
Dam Break ◽  
Plant Distribution ◽  
Computational Domain ◽  
Dam Break Flow ◽  
Volume Method ◽  
Two Sides ◽  
Morphology Characteristics

This study models a dam-break flow over a bed by using a depth-averaged numerical model based on finite-volume method and computes the dam-break flow and bed morphology characteristics. The generalized shallow water equations considering the sediment transport and bed change on dam-break flow are adopted in the numerical model, and the vegetation effects on the flow and morphological changes are considered. The model is verified against three cases from the laboratory and field data documented in the literature. The numerical results are consistent with the measured results, which show that the model could accurately simulate the evolution of the dam-break flows and the morphology evolution of bed within a computational domain with complex plant distribution. The results show that the riparian vegetation in the waterway narrows the channel and reduces the conveyance capacity of river. The flood flow is diverted away from the vegetation community toward two sides and forms a weak flow region behind the vegetation domain. The resistance of plants markedly reduces the flow velocity, which directly alters the fluvial processes and influences the waterway morphology.

Sign in / Sign up

Export Citation Format

Share Document