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

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.

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Numerical Analysis of General Groove Geometry for Dry Gas Seals

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.457-458.544 ◽

2013 ◽

Vol 457-458 ◽

pp. 544-551

Author(s):

Ji Bin Hu ◽

Wen Jin Tao ◽

Yi Min Zhao ◽

Chao Wei

Keyword(s):

Numerical Model ◽

Hydrodynamic Pressure ◽

Computational Domain ◽

System Transformation ◽

Modeling And Analysis ◽

Gas Seals ◽

Groove Seal ◽

Shallow Groove ◽

Regular Region ◽

Volume Method

By Changing the key points on the spiral curve, general groove geometry was determined. Considering the simplicity of modeling and analysis, cubic spline function was used to express the general groove profile. By using the boundary fitted coordinate system transformation, irregular computational domain was transferred to regular region; Based on flow conservation principle, finite volume method was applied to discrete compressible Reynolds equation; By the application of Newton-Raphson iteration method for solving algebraic equation, numerical model of general groove dry gas seals was established. When compared sample results with shallow groove theory, the capacity and stiffness of numerical results match well with theoretical ones, verifying the accuracy of novel numerical model. Through analysis of three typical groove seals, spiral groove seal has strongest carrying capacity. Pressure distribution of three groove seals subjects to the law of hydrodynamic pressure effect. And the numerical model established in this paper will offer a general calculate platform for optimization of groove geometry in the future.

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

Journal of Applied Mathematics ◽

10.1155/2012/489269 ◽

2012 ◽

Vol 2012 ◽

pp. 1-14 ◽

Cited By ~ 8

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.

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

Modelling and Simulation in Engineering ◽

10.1155/2021/9534495 ◽

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.

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

International Journal of Innovative Technology and Exploring Engineering - Special Issue ◽

10.35940/ijitee.i7825.078919 ◽

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.

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NUMERICAL MODELLING OF THE MORPHODYNAMICS OF THE PLOČE GRAVEL BEACH IN RIJEKA

Elektronički časopis građevinskog fakulteta Osijek ◽

10.13167/2021.23.4 ◽

2021 ◽

Vol 12 (23) ◽

pp. 33-48

Author(s):

Goran Lončar ◽

◽

Filip Kalinić ◽

Dalibor Carević ◽

Damjan Bujak ◽

...

Keyword(s):

Sediment Transport ◽

Numerical Model ◽

Morphological Changes ◽

Wind Waves ◽

Surface Wind ◽

Point Clouds ◽

Beach Sediment ◽

Model Simulations ◽

Volume Method ◽

Gravel Beach

The morphodynamics of an artificial gravel beach in the Bay of Rijeka (Ploče Beach) was analyzed. The morphological changes of the beach face were monitored through an intense situation of gravitational surface wind waves from the incident SSW direction. A numerical modeling technique was applied, after initially establishing a numerical model for wave deformation. A model for sediment transport was established based on its results. Both models were based on the finite volume method. In addition, the partial contribution of the longshore component of sediment transport was analyzed based on empirical formulae. The modeling results were verified by comparing the positions and amounts of eroded/accumulated material along the beach with the processing of terrain images in the form of point clouds. The erosion and accumulation positions of the beach sediment material, obtained by numerical model simulations, corresponded to the surveyed positions. The total volume of eroded and accumulated material based on terrain image processing corresponded to the model values.

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

Water Science & Technology ◽

10.2166/wst.2015.324 ◽

2015 ◽

Vol 72 (7) ◽

pp. 1155-1167 ◽

Cited By ~ 1

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.

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