scholarly journals CFD modelling approach for dam break flow studies

2010 ◽  
Vol 14 (4) ◽  
pp. 705-718 ◽  
Author(s):  
C. Biscarini ◽  
S. Di Francesco ◽  
P. Manciola
Keyword(s):  
Shallow Water ◽  
Three Dimensional ◽  
Fluid Flows ◽  
Free Surface Flows ◽  
Dam Break ◽  
Navier Stokes ◽  
Cfd Modelling ◽  
Dam Break Flow ◽  
Complete Set ◽  
Three Dimensional Simulations

Abstract. This paper presents numerical simulations of free surface flows induced by a dam break comparing the shallow water approach to fully three-dimensional simulations. The latter are based on the solution of the complete set of Reynolds-Averaged Navier-Stokes (RANS) equations coupled to the Volume of Fluid (VOF) method. The methods assessment and comparison are carried out on a dam break over a flat bed without friction, a dam break over a triangular bottom sill and a dam break flow over a 90° bend. Experimental and numerical literature data are compared to present results. The results demonstrate that the shallow water approach, even if able to sufficiently reproduce the main aspects of the fluid flows, loses some three-dimensional phenomena, due to the incorrect shallow water idealization that neglects the three-dimensional aspects related to the gravity force.

scholarly journals CFD modelling approach for dam break flow studies

2009 ◽  
Vol 6 (6) ◽  
pp. 6759-6793 ◽  
Author(s):  
C. Biscarini ◽  
S. Di Francesco ◽  
P. Manciola
Keyword(s):  
Shallow Water ◽  
Three Dimensional ◽  
Free Surface Flows ◽  
Dam Break ◽  
Navier Stokes ◽  
Cfd Modelling ◽  
Wave Celerity ◽  
Dam Break Flow ◽  
Complete Set ◽  
First Time

Abstract. This paper presents numerical simulations of free surface flows induced by a dam break comparing the shallow water approach to fully three-dimensional simulations. The latter are based on the solution of the complete set of Reynolds-Averaged Navier-Stokes (RANS) equations coupled to the Volume of Fluid (VOF) method. The methods assessment and comparison are carried out on a dam break over a flat bed without friction and a dam break over a triangular bottom sill. Experimental and numerical literature data are compared to present results. The results demonstrate that the shallow water approach loses some three-dimensional phenomena, which may have a great impact when evaluating the downstream wave propagation. In particular, water wave celerity and water depth profiles could be underestimated due to the incorrect shallow water idealization that neglects the three-dimensional aspects due to the gravity force, especially during the first time steps of the motion.

Three-dimensional flow evolution after a dam break

2010 ◽  
Vol 663 ◽  
pp. 456-477 ◽  
Author(s):  
A. FERRARI ◽  
L. FRACCAROLLO ◽  
M. DUMBSER ◽  
E. F. TORO ◽  
A. ARMANINI
Keyword(s):  
Experimental Data ◽  
Free Surface ◽  
Shallow Water ◽  
Three Dimensional ◽  
Dam Break ◽  
Water Model ◽  
Navier Stokes ◽  
Finite Volume Scheme ◽  
Shallow Water Model ◽  
Weakly Compressible

In this paper, the wave propagation on a plane dry bottom after a dam break is analysed. Two mathematical models have been used and compared with each other for simulating such a dam-break scenario. First, the fully three-dimensional Navier–Stokes equations for a weakly compressible fluid have been solved using the new smooth particle hydrodynamics formulation, recently proposed by Ferrari et al. (Comput. Fluids, vol. 38, 2009, p. 1203). Second, the two-dimensional shallow water equations (SWEs) are solved using a third-order weighted essentially non-oscillatory finite-volume scheme. The numerical results are critically compared against the laboratory measurements provided by Fraccarollo & Toro (J. Hydraul. Res., vol. 33, 1995, p. 843). The experimental data provide the temporal evolution of the pressure field, the water depth and the vertical velocity profile at 40 gauges, located in the reservoir and in front of the gate. Our analysis reveals the shortcomings of SWEs in the initial stages of the dam-break phenomenon in reproducing many important flow features of the unsteady free-surface flow: the shallow water model predicts a complex wave structure and a wavy evolution of local free-surface elevations in the reservoir that can be clearly identified to be only model artefacts. However, the quasi-incompressible Navier–Stokes model reproduces well the high gradients in the flow field and predicts the cycles of simultaneous rapid decreasing and frozen stages of the free surface in the tank along with the velocity oscillations. Asymptotically, i.e. for ‘large times’, the shallow water model and the weakly compressible Navier–Stokes model agree well with the experimental data, since the classical SWE assumptions are satisfied only at large times.

scholarly journals 2D Shallow Water Model for Dam Break and Column Interactions

2020 ◽  
Vol 6 (3) ◽  
pp. 237
Author(s):  
Putu Indah Dianti Putri ◽  
Rifqi Fauzan Iskandar ◽  
Mohammad Bagus Adityawan ◽  
Hadi Kardhana ◽  
Dian Indrawati
Keyword(s):  
Shallow Water ◽  
Numerical Scheme ◽  
Dam Break ◽  
Water Model ◽  
Navier Stokes ◽  
Two Dimensional ◽  
Navier Stokes Equation ◽  
Saint Venant Equations ◽  
Dam Break Flow ◽  
Analytic Models

Dam break causes disastrous effects on the surrounding area, especially at the downstream, therefore, there is a need for accurate and timely predictions of dam break propagation to prevent both property damage and loss of life. This study aimed to determine the movement of dam-break flow in the downstream area by solving the Shallow Water Equations (SWE) or Saint Venant Equations which are based on the conservation of mass and momentum derived from Navier Stokes equation. The model was generated using a finite difference scheme which is the most common and simplest method for dam-break modeling while Forward Time Central Space (FTCS) numerical scheme was applied to simulate two-dimensional SWE. Moreover, the accuracy of the numerical model was checked by comparing its results with the analytic results of one-dimensional cases and a relatively small value of error was found in comparison to the analytic models as indicated with the RMSE values close to 0. The numerical to the two-dimensional models were also compared to a simple dam break in a flume and dam break with column interactions and the wave propagation in both cases was observed to become very close at a certain time.  The model, however, used numerical filter (Hansen) to reduce the oscillations or numerical instability. The simulation and analysis, therefore, showed the ability of the numerical scheme of FTCS to resolve both cases of the simple dam break and dam break with column interactions in the Two-dimensional Shallow Water. 

A three dimensional dam break flow: Small time behavior

2021 ◽  
Vol 110 ◽  
pp. 102583
Author(s):  
Elona Fetahu ◽  
Oguz Yilmaz
Keyword(s):  
Three Dimensional ◽  
Small Time ◽  
Dam Break ◽  
Time Behavior ◽  
Dam Break Flow

scholarly journals Experimental and Numerical Investigation of 3D Dam-Break Wave Propagation in an Enclosed Domain with Dry and Wet Bottom

2021 ◽  
Vol 11 (12) ◽  
pp. 5638
Author(s):  
Selahattin Kocaman ◽  
Stefania Evangelista ◽  
Hasan Guzel ◽  
Kaan Dal ◽  
Ada Yilmaz ◽  
...  
Keyword(s):  
Wave Propagation ◽  
Numerical Models ◽  
Three Dimensional ◽  
Dam Break ◽  
Dam Failure ◽  
Navier Stokes ◽  
Negative Wave ◽  
Through Flow ◽  
Instantaneous Removal ◽  
Surface Patterns

Dam-break flood waves represent a severe threat to people and properties located in downstream regions. Although dam failure has been among the main subjects investigated in academia, little effort has been made toward investigating wave propagation under the influence of tailwater depth. This work presents three-dimensional (3D) numerical simulations of laboratory experiments of dam-breaks with tailwater performed at the Laboratory of Hydraulics of Iskenderun Technical University, Turkey. The dam-break wave was generated by the instantaneous removal of a sluice gate positioned at the center of a transversal wall forming the reservoir. Specifically, in order to understand the influence of tailwater level on wave propagation, three tests were conducted under the conditions of dry and wet downstream bottom with two different tailwater depths, respectively. The present research analyzes the propagation of the positive and negative wave originated by the dam-break, as well as the wave reflection against the channel’s downstream closed boundary. Digital image processing was used to track water surface patterns, and ultrasonic sensors were positioned at five different locations along the channel in order to obtain water stage hydrographs. Laboratory measurements were compared against the numerical results obtained through FLOW-3D commercial software, solving the 3D Reynolds-Averaged Navier–Stokes (RANS) with the k-ε turbulence model for closure, and Shallow Water Equations (SWEs). The comparison achieved a reasonable agreement with both numerical models, although the RANS showed in general, as expected, a better performance.

scholarly journals Investigate Impact Force of Dam-Break Flow against Structures by Both 2D and 3D Numerical Simulations

Water ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 344
Author(s):  
Le Thi Thu Hien ◽  
Nguyen Van Chien
Keyword(s):  
Impact Force ◽  
Numerical Models ◽  
Splitting Method ◽  
Dam Break ◽  
Navier Stokes ◽  
Dynamic Force ◽  
Exact Mass ◽  
Initial Water ◽  
Dam Break Flow ◽  
2D And 3D

The aim of this paper was to investigate the ability of some 2D and 3D numerical models to simulate flood waves in the presence of an isolated building or building array in an inundated area. Firstly, the proposed 2D numerical model was based on the finite-volume method (FVM) to solve 2D shallow-water equations (2D-SWEs) on structured mesh. The flux-difference splitting method (FDS) was utilized to obtain an exact mass balance while the Roe scheme was invoked to approximate Riemann problems. Secondly, the 3D commercially available CFD software package was selected, which contained a Flow 3D model with two turbulent models: Reynolds-averaged Navier-Stokes (RANs) with a renormalized group (RNG) and a large-eddy simulation (LES). The numerical results of an impact force on an obstruction due to a dam-break flow showed that a 3D solution was much better than a 2D one. By comparing the 3D numerical force results of an impact force acting on building arrays with the existence experimental data, the influence of velocity-induced force on a dynamic force was quantified by a function of the Froude number and the water depth of the incident wave. Furthermore, we investigated the effect of the initial water stage and dam-break width on the 3D-computed results of the peak value of force intensity.

CFD modelling of near-field dam break flow

2019 ◽  
pp. 47-60
Author(s):  
S. Esmaeeli Mohsenabadi ◽  
M. Mohammadian ◽  
I. Nistor ◽  
H. Kheirkhah Gildeh
Keyword(s):  
Near Field ◽  
Dam Break ◽  
Cfd Modelling ◽  
Dam Break Flow

GPU Based Acceleration of MPS Method for Three-Dimensional Dam-Break Flows

2018 ◽  
Author(s):  
Xiang Chen ◽  
Decheng Wan
Keyword(s):  
Numerical Methods ◽  
Computational Efficiency ◽  
Three Dimensional ◽  
Computation Time ◽  
Dam Break ◽  
Gpu Acceleration ◽  
Mps Method ◽  
Acceleration Technique ◽  
Dam Break Flow ◽  
Moving Particle

The Moving Particle Semi-implicit (MPS) method has been proven effective to simulate violent flows such as dam-break flow, liquid sloshing and so on. But the low computational efficiency is one disadvantage of MPS. In the field of scientific computations, GPU based acceleration technique is widely applied to reduce the computation time of various numerical methods. In this paper, an in-house solver MPSGPU-SJTU is developed based on modified MPS method and GPU acceleration technique. A three-dimensional (3-D) dam-break flow is simulated by present solver and the validity and accuracy of GPU code are investigated by comparing the results with those by other researches. By comparisons, the flow field of GPU-based calculation is in better agreement with the experiment. In addition, the computation times of GPU and CPU solvers are compared to demonstrate the effect of GPU acceleration technique on the computational efficiency of MPS method.

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