A NUMERICAL STUDY OF DAM-BREAK FLOW AND SEDIMENT TRANSPORT FROM A QUAKE LAKE

2011 ◽  
Vol 05 (05) ◽  
pp. 401-428 ◽  
Author(s):  
PENGZHI LIN ◽  
YINNA WU ◽  
JUNLI BAI ◽  
QUANHONG LIN
Keyword(s):  
Sediment Transport ◽  
Shallow Water ◽  
High Speed ◽  
Numerical Study ◽  
Shallow Water Equation ◽  
Equation Model ◽  
Dam Break ◽  
Bed Morphology ◽  
Dam Break Flow ◽  
Quake Lake

Dam-break flows are simulated numerically by a two-dimensional shallow-water-equation model that combines a hydrodynamic module and a sediment transport module. The model is verified by available analytical solutions and experimental data. It is demonstrated that the model is a reliable tool for the simulation of various transient shallow water flows and the associated sediment transport and bed morphology on complex topography. The validated model is then applied to investigate the potential dam-break flows from Tangjiashan Quake Lake resulting from Wenchuan Earthquake in 2008. The dam-break flow evolution is simulated by using the model in order to provide the flooding patterns (e.g., arrival time and flood height) downstream. Furthermore, the sediment transport and bed morphology simulation is performed locally to study the bed variation under the high-speed dam-break flow.

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 Stable Algorithm Based On Lax-Friedrichs Scheme for Visual Simulation of Shallow Water

2020 ◽  
Vol 8 (1) ◽  
pp. 19-34
Author(s):  
Bandung Arry Sanjoyo ◽  
Mochamad Hariadi ◽  
Mauridhi Hery Purnomo
Keyword(s):  
Numerical Solution ◽  
Shallow Water ◽  
Shallow Water Equation ◽  
Steady State Solution ◽  
Dam Break ◽  
Stability And Convergence ◽  
Flow Depth ◽  
Stable Algorithm ◽  
Long Time ◽  
Dam Break Flow

Many game applications require fluid flow visualization of shallow water, especially dam-break flow. A Shallow Water Equation (SWE) is a mathematical model of shallow water flow which can be used to compute the flow depth and velocity.  We propose a stable algorithm for visualization of dam-break flow on flat and flat with bumps topography. We choose Lax-Friedrichs scheme as the numerical method for solving the SWE. Then, we investigate the consistency, stability, and convergence of the scheme. Finally, we transform the strategy into a visualization algorithm of SWE and analyze the complexity. The results of this paper are: 1) the Lax-Friedrichs scheme that is consistent and conditionally stable; furthermore, if the stability condition is satisfied, the scheme is convergent; 2) an algorithm to visualize flow depth and velocity which has complexity O(N) in each time iteration. We have applied the algorithm to flat and flat with bumps topography. According to visualization results, the numerical solution is very close to analytical solution in the case of flat topography. In the case of flat with bumps topography, the algorithm can visualize the dam-break flow and after a long time the numerical solution is very close to the analytical steady-state solution. Hence the proposed visualization algorithm is suitable for game applications containing flat with bumps environments.

scholarly journals Stochastic Uncertainty in a Dam-Break Experiment with Varying Gate Speeds

2021 ◽  
Vol 9 (1) ◽  
pp. 67
Author(s):  
Hiroshi Takagi ◽  
Fumitaka Furukawa
Keyword(s):  
High Speed ◽  
Pressure Sensors ◽  
Dam Break ◽  
Maximum Pressure ◽  
Vertical Acceleration ◽  
Ship Wakes ◽  
Dam Break Flow ◽  
Statistical Relationships ◽  
Flow Propagation ◽  
Impulsive Pressure

Uncertainties inherent in gate-opening speeds are rarely studied in dam-break flow experiments due to the laborious experimental procedures required. For the stochastic analysis of these mechanisms, this study involved 290 flow tests performed in a dam-break flume via varying gate speeds between 0.20 and 2.50 m/s; four pressure sensors embedded in the flume bed recorded high-frequency bottom pressures. The obtained data were processed to determine the statistical relationships between gate speed and maximum pressure. The correlations between them were found to be particularly significant at the sensors nearest to the gate (Ch1) and farthest from the gate (Ch4), with a Pearson’s coefficient r of 0.671 and −0.524, respectively. The interquartile range (IQR) suggests that the statistical variability of maximum pressure is the largest at Ch1 and smallest at Ch4. When the gate is opened faster, a higher pressure with greater uncertainty occurs near the gate. However, both the pressure magnitude and the uncertainty decrease as the dam-break flow propagates downstream. The maximum pressure appears within long-period surge-pressure phases; however, instances considered as statistical outliers appear within short and impulsive pressure phases. A few unique phenomena, which could cause significant bottom pressure variability, were also identified through visual analyses using high-speed camera images. For example, an explosive water jet increases the vertical acceleration immediately after the gate is lifted, thereby retarding dam-break flow propagation. Owing to the existence of sidewalls, two edge waves were generated, which behaved similarly to ship wakes, causing a strong horizontal mixture of the water flow.

Influence of Wave Shape on the Impact of Shallow-Water Waves on Vertical Walls

2006 ◽  
Author(s):  
Claudio Zanzi ◽  
Pablo Go´mez ◽  
Julia´n Palacios ◽  
Joaqui´n Lo´pez ◽  
Julio Herna´ndez
Keyword(s):  
Shallow Water ◽  
Level Set ◽  
Water Waves ◽  
High Speed ◽  
Numerical Study ◽  
Local Level ◽  
Wave Shape ◽  
Shallow Water Waves ◽  
Vertical Walls ◽  
The Impact

A numerical study of the impact of shallow-water waves on vertical walls is presented. The air-liquid flow was simulated using a code for incompressible viscous flow, based on a local level set algorithm and a second-order approximate projection method. The level set transport and reinitialization equations were solved in a narrow band around the interface using an adaptive refined grid. The wave is assumed to be generated by a plunger which is accelerated in an open channel containing water. An arbitrary Lagrangian-Eulerian method was used to take into account the relative movement between the plunger and the end wall of the channel. The evolution of the free surface was visualized using a laser light sheet and a high-speed camera, with a sampling frequency of 1000 Hz. Several simulations were carried out to investigate the influence of the shape of the wave approaching the wall on the relevant quantities associated with the impact. The wave shape just before the impact was changed varying the total length of the channel. The results are compared with experimental results and with results obtained by other authors.

scholarly journals An improved shallow water equation model for water animation

2017 ◽  
Author(s):  
Mingjing Ai ◽  
Anding Du ◽  
Han Xu ◽  
Jianwei Niu
Keyword(s):  
Shallow Water ◽  
Shallow Water Equation ◽  
Equation Model

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.

scholarly journals Construction, verification of a software for the 2D dam-break flow and some its applications

2007 ◽  
Vol 29 (4) ◽  
pp. 539-550
Author(s):  
Hoang Van Lai ◽  
Nguyen Thanh Don
Keyword(s):  
Shallow Water ◽  
Numerical Method ◽  
Shallow Water Equations ◽  
Theoretical Basis ◽  
Dam Break ◽  
River Delta ◽  
Red River ◽  
Test Cases ◽  
Red River Delta ◽  
Dam Break Flow

In this paper the numerical method for the shallow water equations is studied. The paper consists of 3 sections. In the section 1 the theoretical basis and software IMECI-L2DBREAK for simulation of the 2D dam-break or dyke-break flows is outlined. In the section 2 some results in verification of the IMECH_2DBREAK by the test cases proposed in the big European Hydraulics Laboratories are shown. In the last section some applications of IMECH_2DBREAK for the inundation problem in the Red river delta in the Northern of Vietnam are presented.

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