3D Simulation of Molten Metal Freezing Behaviour Using Finite Volume Particle Method

2010 ◽  
Author(s):  
Rida S. N. Mahmudah ◽  
Masahiro Kumabe ◽  
Takahito Suzuki ◽  
LianCheng Guo ◽  
Koji Morita ◽  
...  
Keyword(s):  
Molten Metal ◽  
Finite Volume ◽  
Particle Method ◽  
Metal Structure ◽  
Freezing Behavior ◽  
Severe Accident ◽  
Particle Methods ◽  
Freezing Process ◽  
Penetration Length ◽  
Moving Particle

Understanding the freezing behavior of molten metal in flow channels is of importance for severe accident analysis of liquid metal reactors. In order to simulate its fundamental behavior, a 3D fluid dynamics code was developed using Finite Volume Particle (FVP) method, which is one of the moving particle methods. This method, which is fully Lagrangian particle method, assumes that each moving particle occupies certain volume. The governing equations that determine the phase change process are solved by discretizing its gradient and Laplacian terms with the moving particles. The motions of each particle and heat transfer between particles are calculated through interaction with its neighboring particles. A series of experiments for fundamental freezing behavior of molten metal during penetration on to a metal structure was also performed to provide data for the validation of the developed code. The comparison between simulation and experimental results indicates that the present 3D code using the FVP method can successfully reproduce the observed freezing process such as molten metal temperature profile, frozen molten metal shape and its penetration length on the metal structure.

Optimization of Moving Particle Semi-Implicit (MPS) Method and Studying of Flow Instability

2018 ◽  
Author(s):  
Kailun Guo ◽  
Ronghua Chen ◽  
Suizheng Qiu ◽  
Wenxi Tian ◽  
Guanghui Su ◽  
...  
Keyword(s):  
Multiphase Flows ◽  
Flow Instability ◽  
Free Particle ◽  
Particle Method ◽  
Severe Accident ◽  
Particle Methods ◽  
Two Phase ◽  
Mps Method ◽  
Viscosity Term ◽  
Moving Particle

Multiphase flow widely exists in the nature and engineering. The two-phase flow is the highlight of the studies about the flow in the vessel and steam explosion in nuclear severe accidents. The Moving Particle Semi-implicit (MPS) method is a fully-Lagrangian particle method without grid mesh which focuses on tracking the single particle and concerns with its movement. It has advantages in tracking complex multiphase flows compared with gird methods, and thus shows great potential in predicting multiphase flows. The objective of this thesis is to develop a general multiphase particle method based on the original MPS method and thus this work is of great significance for improving the numerical method for simulating the instability in reactor severe accident and two-phase flows in vessel. This research is intended to provide a study of the instability based on the MPS method. Latest achievements of mesh-free particle methods in instability are researched and a new multiphase MPS method, which is based on the original one, for simulating instability has been developed and validated. Based on referring to other researchers’ papers, the Pressure Poisson Equation (PPE), the viscosity term, the free surface particle determination part and the surface tension model are optimized or added. The numerical simulation on stratification behavior of two immiscible flows is carried out and results are analyzed after data processing. It is proved that the improved MPS method is more accurate than the original method in analysis of multiphase flows. In this paper, the main purposes are simulating and discussing Rayleigh-Taylor (R-T) instability and Kelvin-Helmholtz (K-H) instability. R-T and K-H instability play an important role in the mixing process of many layered flows. R-T instability occurs when a lower density fluid is supported by another density higher fluid or higher density fluid is accelerated by lower density fluid, and the resulting small perturbation increases and eventually forms turbulence. K-H instability is a small disturbance for two different densities, such as waves, at the interface of the two-phase fluid after giving a fixed acceleration in the fluid. Turbulence generated by R-T instability and K-H instability has an important effect in applications such as astrophysics, geophysics, and nuclear science.

Numerical Simulation of 3D Liquid Sloshing Motion With Solid Particles Using Finite Volume Particle Method

2010 ◽  
Author(s):  
LianCheng Guo ◽  
Shuai Zhang ◽  
Koji Morita ◽  
Kenji Fukuda
Keyword(s):  
Solid Particle ◽  
Finite Volume ◽  
Liquid Mixture ◽  
Particle Method ◽  
Solid Particles ◽  
Liquid Sloshing ◽  
Particle Methods ◽  
3D Motion ◽  
Sloshing Dynamics ◽  
Moving Particle

Sloshing dynamics of a molten core is one of the fundamental behaviors in core disruptive accidents of a liquid-metal cooled reactor. In addition, solid particle-liquid mixture comprising molten fuel, molten structure, refrozen fuel, solid fuel pellets, etc. could lead to damping of its flowing process in a disrupted core. The objective of the present study is to investigate the applicability of the finite volume particle method (FVP), which is one of the moving particle methods, to 3D motion of liquid sloshing processes measured in a series of experiments. In the first part of this study, a typical sloshing experiment of single liquid phase is simulated to verify the present 3D FVP method for sloshing characteristics that include free surface behaviors. Second, simulations of sloshing problems with solid particles are performed to validate the applicability of the FVP method to the 3D motion of solid particle-liquid mixture flows. Some good agreements between the simulation and its corresponding experiment demonstrate applicability of the present FVP method to 3D fluid dynamics of liquid sloshing flow with solid particles.

Experimental and Numerical Investigation of Solidification of Gallium in an Initially Emptied Horizontal Pipe Flow

2020 ◽  
Author(s):  
Shawn Somers-Neal ◽  
Alex Pegarkov ◽  
Edgar Matida ◽  
Vinh Tang ◽  
Tarik Kaya
Keyword(s):  
Numerical Model ◽  
Molten Metal ◽  
Reactor Core ◽  
Experimental Tests ◽  
Severe Accident ◽  
Penetration Length ◽  
Horizontal Pipe ◽  
Cooling Pipe ◽  
Severe Accidents ◽  
Core Meltdown

Abstract In a reactor core meltdown under postulated severe accidents, the molten material (corium) could be ejected or relocated through existing vessel penetrations (cooling pipe connections), thus potentially contaminating other locations in the power plant. There exists, however, a potential for plugging of melt flow due to its complete solidification, providing the availability of an adequate heat sink. Therefore, a numerical model was created to simulate the flow of molten metal through an initially empty horizontal pipe. The numerical model was verified using a previously developed analytical model and validated against experimental tests with gallium (low melting temperature) as a substitute for corium. The numerical model was able to predict the penetration length (length of distance travelled by the molten metal) after a complete blockage occurred with an average percent error range of 9%. Since the numerical model has been verified and validated, the model can be updated to predict the penetration length in the cooling pipe in case of a severe accident.

Finite Volume Particle Method for Incompressible Flows

2014 ◽  
Vol 656 ◽  
pp. 72-80
Author(s):  
Sterian Danaila ◽  
Delia Teleaga ◽  
Luiza Zavalan
Keyword(s):  
Finite Volume ◽  
Meshless Method ◽  
Incompressible Flows ◽  
Particle Method ◽  
Finite Volume Methods ◽  
Particle Methods ◽  
Navier Stokes ◽  
Ansys Fluent ◽  
Manufactured Solutions ◽  
Method Of Manufactured Solutions

This paper presents an application of the Finite Volume Particle Method to incompressible flows. The two-dimensional incompressible Navier-Stokes solver is based on Chorin’s projection method with finite volume particle discretization. The Finite Volume Particle Method is a meshless method for fluid dynamics which unifies advantages of particle methods and finite volume methods in one scheme. The method of manufactured solutions is used to examine the global discretization error and finally a comparison between finite volume particle method simulations of an incompressible flow around a fixed circular cylinder and the numerical simulations with the CFD code ANSYS FLUENT 14.0 is presented.

A NUMERICALLY CONSISTENT MULTIPHASE POISEUILLE FLOW COMPUTATION BY A NEW PARTICLE METHOD

2015 ◽  
Vol 76 (8) ◽  
Author(s):  
K. C. Ng ◽  
Y. H. Hwang ◽  
T. W. H. Sheu ◽  
M. Z. Yusoff
Keyword(s):  
Fluid Flow ◽  
Poiseuille Flow ◽  
Particle Method ◽  
Numerical Approach ◽  
Particle Methods ◽  
Diffusion Term ◽  
Flow Solver ◽  
Mesh Free ◽  
Consistent Method ◽  
Moving Particle

Recently, there is a rising interest in simulating fluid flow by using particle methods, which are mesh-free. However, the viscous stresses (or diffusion term) appeared in fluid flow governing equations are commonly expressed as the second-order derivatives of flow velocities, which are usually discretized by an inconsistent numerical approach in a particle-based method. In this work, a consistent method in discretizing the diffusion term is implemented in our particle-based fluid flow solver (namely the Moving Particle Pressure Mesh (MPPM) method). The new solver is then used to solve a multiphase Poiseuille flow problem. The error is decreasing while the grid is refined, showing the consistency of our current numerical implementation.

scholarly journals A FINITE-VOLUME PARTICLE METHOD FOR COMPRESSIBLE FLOWS

2000 ◽  
Vol 10 (09) ◽  
pp. 1363-1382 ◽  
Author(s):  
DIETMAR HIETEL ◽  
KONRAD STEINER ◽  
JENS STRUCKMEIER
Keyword(s):  
Finite Volume ◽  
Compressible Flows ◽  
Burgers Equation ◽  
Particle Method ◽  
Finite Volume Methods ◽  
Particle Methods ◽  
One Dimensional ◽  
New Class ◽  
Shock Wave Solution ◽  
Volume Method

We derive a new class of particle methods for conservation laws, which are based on numerical flux functions to model the interactions between moving particles. The derivation is similar to that of classical finite-volume methods; except that the fixed spatial mesh in a finite-volume method is substituted by so-called mass packets of particles. We give some numerical results on a shock wave solution for Burgers equation as well as the well-known one-dimensional shock tube problem.

scholarly journals Application of background pressure with kinematic criterion for free surface extension to suppress non-physical voids in the finite volume particle method

2019 ◽  
Author(s):  
Nathan Quinlan ◽  
Mohsen Hassanzadeh Moghimi
Keyword(s):  
Free Surface ◽  
Finite Volume ◽  
Particle Method ◽  
Free Surface Flow ◽  
Surface Flow ◽  
Particle Methods ◽  
Positive Pressure ◽  
Absolute Pressure ◽  
Free Surfaces ◽  
Spatial Discretisation

Lagrangian particle methods such as smoothed particle hydrodynamics (SPH) and the finite volume particle method (FVPM) can suffer from non-physical voids in the spatial discretisation, due to the inability of numerical particles to deform as continuum fluid elements can. It is known that the situation can be improved for wall-bounded flows in SPH by adding a uniform background pressure to ensure positive absolute pressure everywhere. In this article, we investigate the application of background pressure in FVPM, and show that numerical voids grow under negative pressure and collapse under positive pressure. To use this technique in free-surface flow, however, the background pressure must be applied as an atmospheric pressure at the free surface. A kinematic criterion for free surface extension (KCFSE) to differentiate physical free surfaces from new numerical voids has been developed, supplementing the inherent capability of FVPM to identify free-surface particles robustly. The novel method enables background pressure to be applied at physical free surfaces and throughout the fluid, but not in non-physical voids, facilitating the suppression of such spurious voids. The KCFSE is validated for a translating square cylinder inside a rectangular numerical domain, with and without a free surface, and liquid in an oscillating rectangular tank.

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