Methods for Estimating the Impact of Hypothetical Dam Break Floods

2007 ◽  
pp. 195-199
Author(s):  
Jene Michaud ◽  
Carl Johnson ◽  
Judy Iokepa ◽  
Jillian Marohnic
Keyword(s):  
Dam Break ◽  
The Impact

Investigations of Reduction Effect of Vertical Wall on Dam-Break-Simulated Tsunami Surge Exerted on Wharf Piles

2018 ◽  
Vol 12 (02) ◽  
pp. 1840006 ◽  
Author(s):  
Cheng Chen ◽  
Bruce W. Melville ◽  
N. A. K. Nandasena
Keyword(s):  
High Speed ◽  
Preliminary Investigation ◽  
Vertical Wall ◽  
Pressure Sensors ◽  
Time History ◽  
Dam Break ◽  
Reservoir System ◽  
Reduction Effect ◽  
The Impact ◽  
Surge Height

For a preliminary investigation of the impact of a tsunami surge on wharf piles, a tsunami flume was built in a laboratory, and a dam break flow was generated by a gate-reservoir system to simulate a tsunami surge. In addition, a vertical wall was installed in front of the wharf model so that its effect in reducing tsunami load could be studied. Five different tsunami surge strengths were generated by this gate-reservoir system. Wave transducers were used in the test flume to capture surge heights and velocities, and hence the surge front profiles, for different surge strengths. High-speed video cameras (210 frames per second) were used to record the flow motion of the tsunami surge, and pressure sensors (1000[Formula: see text]Hz in frequency) were used to capture the time histories of the tsunami pressure on the wharf piles. Four stages of tsunami surge motions were observed by this high-speed camera. Accordingly, the pressure time history can be divided into three phases. In our experimental range, pressures were influenced by surge height and wall height, but not by the wall position. Based on the dimensionless experimental data (pile heights, surge heights, vertical wall heights, and surge pressures), equations for estimating tsunami loads on wharf pile are proposed, expressing surge front (peak impact) pressure and quasi-steady pressure as functions of surge height, wall height, and pile height.

scholarly journals Coupled DEM-SPH Method for Interaction between Dilated Polyhedral Particles and Fluid

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Shunying Ji ◽  
Xiaodong Chen ◽  
Lu Liu
Keyword(s):  
Numerical Simulation ◽  
Parallel Algorithm ◽  
Granular Materials ◽  
Computational Efficiency ◽  
Dam Break ◽  
Solid Interface ◽  
Fluid Media ◽  
Complex Fluid ◽  
Simulation Results ◽  
The Impact

The discrete element method (DEM) and smoothed particle hydrodynamics (SPH) can be adopted to simulate the granular materials and fluid media respectively. The DEM-SPH coupling algorithm can be developed for the dynamic interaction between the two media. When the particle material is simulated by polyhedral element, a fluid-solid coupling interface would lead to the complex geometry between the granular particle and the fluid. The boundary particle method is traditionally used for the fluid-solid interface but with low computational efficiency. In this paper, the dilated polyhedral element is constructed based on Minkowski sum theory, while the contact force between the elements is calculated by Hertzian contact model. Accordingly the dilated polyhedra based DEM is established. The weakly compressible SPH is adopted to simulate the fluid medium, while the interaction on the geometrically complex fluid-solid interface is evaluated with the repulsive force model which can be determined by the contact detection between SPH particles and solid particles in geometry. This method avoids the storage and calculation of a large number of boundary particles, which can be potentially applied for the complex fluid-solid boundary. In order to improve the computational efficiency, a GPU-based parallel algorithm is employed to achieve high performance computation of SPH. The acceleration of the parallel algorithm is evaluated by the cases of dam break. The numerical simulation of the impact of dam break on cubes is implemented. The simulation results are verified with the corresponding experimental and simulation results. Therefore, the rationality and accuracy of the DEM-SPH coupling method for numerical simulation of the interaction between granular materials and fluid media are illustrated. This method is then adopted for the impact of falling rocks on underwater pipeline. The force of water and rocks on the pipeline is analyzed. This method can be further applied for real engineering problems.

scholarly journals Pressure evaluation during dam break using weakly compressible SPH

2019 ◽  
Vol 213 ◽  
pp. 02030
Author(s):  
Petr Jančík ◽  
Tomáš Hyhlík
Keyword(s):  
Experimental Data ◽  
Smoothed Particle Hydrodynamics ◽  
Two Dimensions ◽  
Dam Break ◽  
Kinematics And Dynamics ◽  
Sph Method ◽  
Weakly Compressible ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
The Impact

This paper presents a solution of a dam break problem in two dimensions obtained with smoothed particle hydrodynamics (SPH) method. The main focus is on pressure evaluation during the impact on the wall. The used numerical method and the way of pressure evaluation are described in detail. The numerical results of the kinematics and dynamics of the flow are compared with experimental data from the literature. The abilities and limitations of the used methods are discussed.

Assessment of the impact of a dam break on the durability of the transport structure

2020 ◽  
Vol 2020 (21) ◽  
pp. 226-235
Author(s):  
Andrii Koretskyi ◽  
◽  
Artur Onyshchenko ◽  
Borys Ostroverh ◽  
Iryna Bashkevych ◽  
...  
Keyword(s):  
Dam Break ◽  
The Impact

scholarly journals On Dam-Break Flow Routing in Confluent Channels

2019 ◽  
Vol 16 (22) ◽  
pp. 4384
Author(s):  
Sihan Chen ◽  
Yingjin Li ◽  
Zhong Tian ◽  
Qiang Fan
Keyword(s):  
Flow Field ◽  
Arrival Time ◽  
Processing Technique ◽  
Surface Flow ◽  
Dam Break ◽  
Image Processing Technique ◽  
Physical Experiments ◽  
Dam Break Flow ◽  
The Impact ◽  
Motion Images

The flood propagation at a confluence of channels exhibits a unique routing pattern, while there are few studies on the routing of dam-break flow in confluent channels. In this study, we conducted physical experiments and a numerical simulation to investigate the influence of different confluence angles on the routing of a dam-break flood. Experiments were carried out in smooth, transparent, rectangular prismatic channels to study the dam-break flow under four different confluence angles. The flow velocity was measured using an image processing technique, and the surface flow field was effectively captured by synchronously recording the particle motion images. Based on the variation of the water level and flow discharge, as the confluence angle increased, the retardation and abatement effects on the flood increased. Specifically, the flood arrival time was delayed by approximately 0.91% to 21.18%, and the peak flood discharge was reduced by approximately 9.05% to 58.36%. Combined with the surface flow field at the confluence and in the downstream sections, as the confluence angle increased, the impact points at the confluence and in the downstream straight sections moved upward, and the impact range was reduced. Combined with the pressure variation pattern, the routing of dam-break flow in the confluent channels experienced a process of impact-reflection-return-attenuation.

scholarly journals Impact Force of a Geomorphic Dam-Break Wave against an Obstacle: Effects of Sediment Inertia

Water ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 232
Author(s):  
Cristiana Di Cristo ◽  
Massimo Greco ◽  
Michele Iervolino ◽  
Andrea Vacca
Keyword(s):  
Impact Force ◽  
Dam Break ◽  
Solid Particles ◽  
Physical Damage ◽  
Two Phase ◽  
Rigid Obstacle ◽  
Shallow Water Approximation ◽  
Set Up ◽  
The Impact

The evaluation of the impact force on structures due to a flood wave is of utmost importance for estimating physical damage and designing adequate countermeasures. The present study investigates, using 2D shallow-water approximation, the morphodynamics and forces caused by a dam-break wave against a rigid obstacle in the presence of an erodible bed. A widely used coupled equilibrium model, based on the two-dimensional Saint–Venant hydrodynamic equations combined with the sediment continuity Exner equation (SVEM), is compared with a more complex two-phase model (TPM). Considering an experimental set-up presented in the literature with a single rigid obstacle in a channel, two series of tests were performed, assuming sand or light sediments on the bottom. The former test is representative of a typical laboratory experiment, and the latter may be scaled up to a field case. For each test, two different particle diameters were considered. Independently from the particle size, it was found that in the sand tests, SVEM performs similarly to TPM. In the case of light sediment, larger differences are observed, and the SVEM predicts a higher force of about 26% for both considered diameters. The analysis of the flow fields and the morphodynamics shows these differences can be essentially ascribed to the role of inertia of the solid particles.

Numerical investigation of the impact of a dam-break induced flood on a structure

2021 ◽  
Vol 223 ◽  
pp. 108669
Author(s):  
Ling Peng ◽  
Ting Zhang ◽  
Youtong Rong ◽  
Chunqi Hu ◽  
Ping Feng
Keyword(s):  
Numerical Investigation ◽  
Dam Break ◽  
The Impact

scholarly journals OpenFOAM Based Approach for the Prediction of the Dam Break with an Obstacle

2020 ◽  
Author(s):  
Richmond Sam Quarm
Keyword(s):  
Numerical Solution ◽  
Vertical Wall ◽  
Leading Edge ◽  
Numerical Approach ◽  
Dam Break ◽  
Free Surface Elevation ◽  
Before And After ◽  
The Difference ◽  
The Impact ◽  
Simulation Time

The phenomenon of the flow impact on a vertical wall resulting from a dam problem is simulated by using OpenFOAM. In this simulation, a dam break was also simulated with the addition of obstacles with various dimensions. The aim of this study is to assess the accuracy of the solver for problems in the impact wave category from the experimental results of previous researchers and other numerical solution techniques compared with the results of this solver. Different aspects of flow such as free surface elevation before and after the initial impact have been observed in depth. The method used in this research is numerical computation simulation with the OpenFOAM approach which has the advantage of being more accurate and fast simulation time. The variations in the dimensions of the obstacle in this study were b / h = 0.25, b / h = 0.5 and b / h = 1.0. From the simulation data, it is found that the numerical approach has been validated through quantitative comparisons with experimental measurements. The computational positions of the leading edge of the collapsed water column match the experimental data. The difference between the experiment and this numerical solution is below 2%.

scholarly journals Kinematic and dynamic analysis of dam break flow impact on vertical walls using weakly compressible SPH

2021 ◽  
Vol 15 (2) ◽  
Author(s):  
Petr Jančík ◽  
Tomáš Hyhlík
Keyword(s):  
Dynamic Analysis ◽  
Evaluation Method ◽  
Numerical Solutions ◽  
Vertical Wall ◽  
Dam Break ◽  
Column Height ◽  
Width Ratio ◽  
Total Force ◽  
Dam Break Flow ◽  
The Impact

This article presents the kinematic and dynamic analysis of a dam break flow based on data obtained from numerical solutions by the smoothed particle hydrodynamics (SPH) method. The method and original algorithms necessary for correct pressure evaluation are thoroughly described. The pressure evaluation method consists of data reading using virtual sensors and filtration in the time domain using the weight function. A simple convergence study showing the independency of the evaluated parameters of spatial resolution is presented together with validation of the introduced methods and algorithms using a simple hydrostatic problem and experimental data available in the literature. We focus on two parameters that describe the problem: distance of the downstream vertical wall from the edge of the liquid column and the column’s height to width ratio. We found that the impact can be divided into three consecutive phases characterized by specific kinematic (flow patterns) and dynamic (exerted pressure and forces) behavior and different roles of the investigated parameters during these phases. During the early stages of an impact, the column’s distance from the vertical wall plays a major role. A dependency between the column distance and the force peak in this stage was identified in the form of a power function. In the second stage, when a rolling wave emerges, the vertical wall position influences the shape of the wave and the pressure distribution on the wall. The total force is greater in this phase for lower column height to width ratios due to the higher total momentum of the liquid. In the third stage, when the rolling wave impacts the liquid surface, the employed methodology with two-dimensional solution and free-surface approach seems to reach its limits of applicability. A more complex modelling would be necessary to capture this phase of the impact properly.

scholarly journals Impacts of Dam Break at Upstream of Lo River on Red River and Thai Binh River Delta

2019 ◽  
Vol 9 (1) ◽  
pp. 6371-6378
Keyword(s):  
Simulation Model ◽  
Lag Time ◽  
Dam Break ◽  
River Delta ◽  
Red River ◽  
Dam Safety ◽  
Large Reservoir ◽  
Economic Area ◽  
Response Measures ◽  
The Impact

The Red River - Thai Binh River Delta is a large economic area, densely populated, especially Hanoi, the capital of Vietnam. This is the key area protected by the dike system that has been built for nearly 1000 years. Recently, along with the dike system, the Red River - Thai Binh River Delta is also protected by a large reservoir system at upstream. However, this raises concerns about dam safety, and requires assessments about the impact of dam break on the delta to prepare appropriate response measures. This paper applies 2D mathematical simulation model of flood propagation due to dam break at Thac Ba and Tuyen Quang reservoirs. The results clearly show the characteristics of the flood caused by dam break (such as water level, depth, velocity, lag time) in affected areas. Furthermore, overflow incident of main dikes and ring dikes at the downstream areas is also determined for both cases dam break with flood and without flood.

Sign in / Sign up

Export Citation Format

Share Document