A multiphase MPS method coupling fluid–solid interaction/phase-change models with application to debris remelting in reactor lower plenum

2022 ◽  
Vol 166 ◽  
pp. 108697
Author(s):  
Guangtao Duan ◽  
Akifumi Yamaji ◽  
Mikio Sakai
Keyword(s):  
Phase Change ◽  
Change Models ◽  
Mps Method ◽  
Fluid Solid Interaction ◽  
Interaction Phase

Coupled Electro-Thermal-Phase Change Modeling of a Chalcogenide Switch

2006 ◽  
Author(s):  
Navdeep Singh Dhillon ◽  
Jayathi Y. Murthy
Keyword(s):  
Heat Transfer ◽  
Phase Change ◽  
Charge Transport ◽  
Crystallization Kinetics ◽  
Change Models ◽  
Switching Model ◽  
Memory Switching ◽  
Continuity Equations ◽  
Thermal Phase ◽  
Fully Coupled

A coupled electro-thermal-phase change numerical model is developed to model the threshold and memory switching processes in a chalcogenide switch based on phase change memory (PCM) technology. Coupled electrical and thermal transport coupled to phase change and crystallization kinetics are solved. Charge transport has been implemented using simplified carrier continuity equations with a threshold switching model for electrical conductivity. Heat transfer is modeled using a Fourier model, accounting for latent heat through a fixed-grid enthalpy formulation. Phase change is modeled using the Johnson-Mehl equations for crystallization kinetics. Thermal conductivity and electrical resistivity changes due to phase change are modeled using a local percolation model. The charge transport and circuit equations are fully coupled with the heat transfer and phase change models to accurately simulate the switching process. SET and RESET pulses are simulated to demonstrate that the model is able to capture the underlying physics well.

Numerical Simulation of Immersion Quench Cooling Process: Part I

2008 ◽  
Author(s):  
Vedanth Srinivasan ◽  
Kil-min Moon ◽  
David Greif ◽  
DeMing Wang ◽  
Myung-hwan Kim
Keyword(s):  
Phase Change ◽  
Nucleate Boiling ◽  
Vapor Flow ◽  
Cooling Process ◽  
Change Models ◽  
Liquid Domain ◽  
Commercial Code ◽  
Quenching Process ◽  
Solid Part ◽  
Quench Cooling

In this article, we describe a newly developed modeling procedure to simulate the immersion quench cooling process using the commercial code AVL-FIRE. The boiling phase change process, triggered by the dipping hot solid part into a subcooled liquid bath and the ensuing two-phase flow is handled using an Eulerian two-fluid method. Mass transfer effects are modeled based on different boiling modes such as film or nucleate boiling regime prevalent in the system. Separate computational domains constructed for the quenched solid part and the liquid (quenchant) domain are numerically coupled at the interface of the solid-liquid boundaries using the AVL-Code-Coupling-Interface (ACCI) feature. The advanced ACCI procedure allows the information pertaining to the phase change rates in the liquid domain to appear as cooling rates on the quenched solid boundaries. As a consequence, the code handles the multiphase flow dynamics in the liquid domain in conjunction with the temperature evolution in the solid region in a tightly coupled fashion. The methodology, implemented in the commercial code AVL-FIRE, is exercised in simulating the quenching of solid parts. In part I of the present research, phase change models are validated by simulating a work piece quenching process for which measurement data are available for various water temperature ranging from 20C to 80C. The computations provide a detailed description of the vapor and temperature fields in the liquid and solid domain at various time instants. In particular, the modifications arising in the liquid-vapor flow field in the near vicinity of the solid interface as a function of the boiling mode is well accommodated. The temperature history predicted by our model at different monitoring points, under different subcooling conditions, correlate very well with the experimental data wherever available. In part II, the model is further applied to real engine cylinder head quenching process and assessment is made for the cooling curves for various measuring points. Overall, the predictive capability of the new quenching model is well demonstrated.

Interfaces in Higher Order Phase Change Models

1984 ◽  
Vol 111 (1-2) ◽  
pp. 45-56
Author(s):  
P. Delano Hagan-Von Dreele ◽  
P. H. Von Dreele
Keyword(s):  
Phase Change ◽  
Higher Order ◽  
Change Models

Three-Dimensional Numerical Study on Pool Stratification Behavior in Molten Corium-Concrete Interaction (MCCI) With MPS Method

2018 ◽  
Author(s):  
Xin Li ◽  
Ikken Sato ◽  
Akifumi Yamaji ◽  
Guangtao Duan
Keyword(s):  
Liquid Phase ◽  
Phase Change ◽  
Molten Pool ◽  
Numerical Study ◽  
Three Dimensional ◽  
Metallic Phase ◽  
Severe Accident ◽  
Mps Method ◽  
Solid Liquid ◽  
Concrete Interface

Molten corium-concrete interaction (MCCI) is an important ex-vessel phenomenon that could happen during the late phase of a hypothetical severe accident in a light water reactor. When the molten corium, which is generally comprised of UO2, ZrO2 and metals such as zircalloy and stainless steel, is discharged into a dry reactor cavity, a stratified molten pool configuration with two immiscible oxidic and metallic phases can be expected to form and lead to MCCI. Compared to a homogenous oxidic molten pool configuration, the metallic phase in the stratified molten pool might influence the crust formation on the corium-concrete interface and consequently cause different concrete ablation behavior to evaluate MCCI progression concerning containment failure. In terms of this issue, past experimental studies, such as COMET-L, VULCANO VBS and MOCKA test series, have been carried out to investigate the influence of such oxidic and metallic stratified pool configuration on MCCI. The experimental results have shown that the metallic phase can have a significant impact on the axial and radial ablation kinetics that could influence the ablation patterns of reactor pit. As regards numerical studies, past numerical modeling of MCCI was generally based on Eulerian methods and simplified empirical approach to simulate solid/liquid phase change and evolving of corium/crust/concrete interface. Such modeling might be efficient but have shown deficiencies and inadequacies due to its Eulerian and empirical nature, which has suggested a necessity to seek for a more mechanistic approach for modeling of MCCI. In this sense, Moving Particle Semi-implicit (MPS) method is considered suitable for MCCI analysis for its advantages of tracking interfaces and modeling phase change accurately as a Lagrangian particle method. In the present study, a three-dimensional (3-D) numerical study has been performed to simulate COMET-L3 test carried out by KIT with a stratified molten pool configuration of simulant materials with improved MPS method. Solid/liquid phase change was simulated with types of solid and liquid particles with thermal and physical properties including temperature and solid fraction, which enabled tracking of the solid/liquid status of each particle to achieve accurate free surface and corium/crust/concrete interface capturing. The heat transfer between corium/crust/concrete was modeled with heat conduction between particles. Moreover, the potential influence of the siliceous aggregates was also investigated by setting up two different case studies since there was previous study indicating that siliceous aggregates in siliceous concrete might contribute to different axial and radial concrete ablation rates. The simulation results have indicated that metal melt as corium in MCCI can have completely different characteristics regarding concrete ablation pattern from that of oxidic corium, which needs to be taken into consideration when assessing the containment melt-through time in severe accident management.

Comparison of numerical phase-change models through Stefan vaporizing problem

2017 ◽  
Vol 87 ◽  
pp. 228-236 ◽  
Author(s):  
Dae Gon Kim ◽  
Chul Hong Jeon ◽  
Il Seouk Park
Keyword(s):  
Phase Change ◽  
Change Models

scholarly journals Development of 3D coupling model considered fluid-solid interaction by MPS method

2010 ◽  
Vol 66 (1) ◽  
pp. 41-45 ◽  
Author(s):  
Toshinori OGASAWARA ◽  
Shigetomo KIKUCHI ◽  
Togo SUNAGAWA ◽  
Shigeki SAKAI
Keyword(s):  
Coupling Model ◽  
Mps Method ◽  
Fluid Solid Interaction

scholarly journals Nonlinear evolution inclusions arising from phase change models

2007 ◽  
Vol 57 (4) ◽  
pp. 1067-1098 ◽  
Author(s):  
Pierluigi Colli ◽  
Pavel Krejčí ◽  
Elisabetta Rocca ◽  
Jürgen Sprekels
Keyword(s):  
Phase Change ◽  
Nonlinear Evolution ◽  
Evolution Inclusions ◽  
Change Models
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