In this paper, it was considered a numerical simulation of the water surface movement during the partial collapse of the destruction of a dam with complex terrain. The numerical simulations took into account debris af...
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In this paper, it was considered a numerical simulation of the water surface movement during the partial collapse of the destruction of a dam with complex terrain. The numerical simulations took into account debris after a partial collapse of the dam, which imitates debris and moves downstream with the water flow. Carrying out these calculations brings the results closer to the real scenario. The mathematical model was based on the Navier-Stokes equations and uses the turbulent large eddy method (LES) model describing the flow of an incompressible viscous fluid. To describe the movement of a two-phase fluid, the volume of fluid (VOF) methods for the phase were used, and the Discrete Phase Model (DPM) and Macroscopic Particle Model (MPM) were used to describe the movement of particles. For the numerical solution of this system of equations, the Pressure Implicit Split Operator (piso) numerical algorithm was chosen. The results show that the model is accurate and capable of handling very complex interactions such as particle transport or hydrodynamic actions on structures if the appropriate scales are reproduced. Also in this work, a three-dimensional (3D) model of the flow of a dam break on uneven terrain was considered and combined problems were performed that are closer to real conditions. For combined problems, flood zones and flood times were determined, knowledge of which will help evacuate people from dangerous areas. The accuracy of the 3D model and the selected numerical algorithm were verified using two natural measurements.
This paper aims to investigate a dam break in a channel with a bend in the presence of several *** accurately determine the flood zones,it is necessary to take into account many factors such as terrain,reservoir *** m...
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This paper aims to investigate a dam break in a channel with a bend in the presence of several *** accurately determine the flood zones,it is necessary to take into account many factors such as terrain,reservoir *** modeling was used to determine the flood *** modeling based on the Navier-Stokes equations with a turbulent k-epsilon RNG model,the Volume of Fluid(VOF)method and the piso algorithm were used to analyze the flow in a bend channel at an angle of 10 with the *** verify the numerical model,a test on dam break in the 450 channel was *** simulation results were compared with experimental data and with the numerical data of existing *** been convinced of the correctness of the mathematical model,the authors carried out a numerical simulation of the main problem in three versions:without barriers,with one obstacle,with two *** to the obtained numerical results,it can be noted that irregular landforms held the flow,a decrease in water level and a slower time for water emergence could be ***,the water flow without an obstacle,with one obstacle and with two obstacles showed 4.2 s,4.4 s and 4.6 s of the time of water appearance,*** time shift can give a certain advantage when conducting various events to evacuate people.
This paper presents a segregated algorithm to solve numerically the superfluid helium (He II) equations using the two-fluid model. In order to validate the resulting code and illustrate its potential, different simula...
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This paper presents a segregated algorithm to solve numerically the superfluid helium (He II) equations using the two-fluid model. In order to validate the resulting code and illustrate its potential, different simulations have been performed. First, the flow through a capillary filled with Hell with a heated area on one side is simulated and results are compared to analytical solutions in both Landau and Gorter-Mellink flow regimes. Then, transient heat transfer of a forced flow of He Ills investigated. Finally, some two-dimensional simulations in a porous medium model are carried out. (C) 2014 Elsevier B.V. All rights reserved.
In this paper, the effects of water on obstacles in dam-break flow for different angles of the inclined planes have been numerically examined. The presented computational data are compared with data from the experimen...
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In this paper, the effects of water on obstacles in dam-break flow for different angles of the inclined planes have been numerically examined. The presented computational data are compared with data from the experiment and computational simulation data of other authors. Good agreements between the obtained simulation results and measurement data demonstrate the satisfactory performance of the mathematical model and the numerical algorithm when reproducing a dam-break flow. Additionally, various problems were also considered: the effect of pressure distribution on the dam walls for different angles of the inclined plane. It was found that pressure distribution on the wall when the inclined angle gamma = 15 degrees was almost two times more than without inclination. To reduce the shock pressure value a new form of obstacle was used. With a new form of obstacle, the maximum pressure value on the dam wall decreased more than three times.
In this paper, the movement of the water surface with macroscopic particles during a dam break flow using the volume of fluid (VOF) methods, the discrete phase model (DPM) and macroscopic particle model (MPM) models w...
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In this paper, the movement of the water surface with macroscopic particles during a dam break flow using the volume of fluid (VOF) methods, the discrete phase model (DPM) and macroscopic particle model (MPM) models were numerically simulated. To solve this equation system numerically, the piso numerical algorithm was chosen. The accuracy of the 3D model and the selected numerical scheme were tested using some laboratory measurements on the destruction of the dam break problem. In the test problem, the values were matched with measurement values and simulation data of other authors. Furthermore, two problems were also considered, the first problem is dam break flow with macroscopic particles, and the second problem - water movement with macroscopic particles, through a heterogeneous terrain and a dam that has a hole. With the help of the problems, the flooding zones and the time of flooding evacuating people from dangerous areas were determined.
This paper considered the problem of numerical simulation of an incompressible dam break flow consisting of three phases. The movement of the water free surface was carried out using the Newtonian fluid model, and the...
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This paper considered the problem of numerical simulation of an incompressible dam break flow consisting of three phases. The movement of the water free surface was carried out using the Newtonian fluid model, and the mud impurity movement was performed by the non-Newtonian fluid model based on the VOF method. The piso numerical algorithm was chosen as a numerical method for solving equations. This paper discusses the problems of dynamic loads arising from the impact of a dam break flow using numerical modeling. The obtained numerical results were compared with the two experiment results, which allow confirming the behavior of the instantaneous flow and the evolution of pressure at the relative points of the obstacle. Moreover the water flow and non-Newtonian fluid for different forms of obstacles were also modeled. It was found that a non-Newtonian fluid extremely reduces the maximum shock pressure value of the water flow.
This paper considered the problem of numerical simulation of an incompressible dam break flow consisting of three phases. The movement of the water free surface is performed using the Newtonian fluid model, and the mu...
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This paper considered the problem of numerical simulation of an incompressible dam break flow consisting of three phases. The movement of the water free surface is performed using the Newtonian fluid model, and the mud mixture movement is carried out by the non-Newtonian fluid model based on the VOF method. The piso numerical algorithm was selected as a numerical method for solving equations. This paper discusses the problems of dynamic loads arising from the impact of a dam break flow using numerical modeling. The received computational data are matched with the two experiment results, which allow confirming the behavior of the instantaneous flow and the evolution of pressure at the relative points of the obstacle. The water flow and non-Newtonian fluid for different forms of obstacles were also modeled. It was found that a non-Newtonian fluid rather strongly reduces the maximum shock the pressure value of the water flow.
In this study, a method based on the Navier-Stokes equation was developed to simulate the dam break flow. The free surface movement of water is carried out using the Newtonian fluid model, and the mud impurity movemen...
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In this study, a method based on the Navier-Stokes equation was developed to simulate the dam break flow. The free surface movement of water is carried out using the Newtonian fluid model, and the mud impurity movement is performed by the model of non-Newtonian fluid based on the volume of fluid (VOF) method. In order to minimize the fluctuations of the free surface near a moving front, the VOF method was used. The numerical Pressure-Implicit with Splitting of Operators (piso) algorithm was chosen as a numerical method for solving equations. The developed model is verified with a wide range of measurement results and with the computational data of other authors. Good computational data were obtained from flood forecasting resulting from the instantaneous collapse of the dam. It has been demonstrated that this model is well balanced and reliable, and can accurately record the movement of dam break in difficult terrain. With the help of the proposed model, the Mynzhylky dam break flow was modeled.
In the present paper, the non-iterative piso algorithm and finite volume method are employed to solve the exact Bingham fluid flow. The OpenFOAM solver, i.e., icoFoam, is modified to achieve this goal. The accuracy of...
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In the present paper, the non-iterative piso algorithm and finite volume method are employed to solve the exact Bingham fluid flow. The OpenFOAM solver, i.e., icoFoam, is modified to achieve this goal. The accuracy of numerical procedures is obtained by reproducing the results of Chupin and Dubois (Comput Math Appl 72:1263-1286, 2016. doi:10.1016/***.2016.06.026). Then, the Bingham fluid flow in a cylindrical enclosure with the rotating top wall is numerically studied by the modified solver for the following ranges of conditions: Reynolds number, 1 <= Re <= 1000, Bingham number, 0 <= Bn <= 1000 and aspect ratio (AR) of 1, 1/2, 1/4, 1/8 and 1/16. The variation of yielded regions percentage with Re and Bn is plotted for AR = 0.5 and 1. It is found that Reynolds number change in the range 1 <= Re <= 10Bn has no significant effect on the size and shape of the unyielded regions for constant Bn and AR = 1. The effect of Re, Bn and AR on the primary (Qp*) and secondary (Qs*) volumetric flow rate is also discussed. A correlation is proposed in terms of Re and Bn to approximate the torque coefficient (CT) for 1 <= Re <= 100,0 <= Bn <= 1000, and different aspect ratios.
In this paper, the movement of the water surface is numerically simulated when a dam is broken by the volume of fluid (VOF) method. The mathematical model is based on the Navier-Stokes equations and uses the LES turbu...
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In this paper, the movement of the water surface is numerically simulated when a dam is broken by the volume of fluid (VOF) method. The mathematical model is based on the Navier-Stokes equations and uses the LES turbulent model, describing the flow of an incompressible viscous fluid and the equation for the phase. These equations are discretized by the finite volume method. Numerical piso algorithm was chosen for numerical solution of this equation system. The movement of the water surface is captured by using the VOF method, which leads to a strict mass conservation law. The accuracy of the 3D model and the chosen numerical algorithm were tested using several laboratory experiments on dam break problem. In each of the problems, the obtained results were compared with the experimental data and several calculations by other authors and in each of the test problems, the developed model showed results close to the experimental data. Comparison of simulation results with experimental data for various turbulent models was also performed. And also a three-dimensional model of dam break flow on uneven terrain was developed. And also two combined problems were performed which are more close to real conditions, with the help of these problems, flooding zones and flooding time were identified that would help in evacuating people from dangerous zones. (C) 2019 Elsevier Ltd. All rights reserved.
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