Fixed Mesh Finite Element Solution for Cartesian Two-Dimensional Phase Change

1983 ◽  
Vol 105 (4) ◽  
pp. 436-441 ◽  
Author(s):  
K. O’Neill
Keyword(s):  
Finite Element ◽  
Phase Change ◽  
Linear Interpolation ◽  
Step Change ◽  
Test Cases ◽  
Two Dimensional ◽  
Freezing And Thawing ◽  
Discrete Phase ◽  
Computer Codes ◽  
Natural Way

An algorithm has been developed for two-dimensional freezing and thawing problems, which may also be useful for some other phase change problems. It is designed to be implemented simply in standard finite element heat conduction computer codes which use linear interpolation within elements. Substances with discrete phase change temperatures, such as water, suffer a step change in enthalpy across a phase change isotherm, and hence, feature a theoretically infinite heat capacity there. The algorithm handles this potentially troublesome phenomenon in a natural way through usual finite element procedures, using simple closed form expressions. A program incorporating the algorithm produced stable, accurate, and economical simulations when run for radial and two-dimensional test cases with exact analytical solutions.

A two-dimensional simulation of solidification processes in materials with thermo-dependent properties using XFEM

2016 ◽  
Vol 26 (6) ◽  
pp. 1661-1683 ◽  
Author(s):  
Pawel Stapór
Keyword(s):  
Finite Element ◽  
Phase Change ◽  
Dimensional Space ◽  
Benchmark Problems ◽  
Liquid Region ◽  
Two Dimensional ◽  
Linear Phase ◽  
Content Type ◽  
Non Linear ◽  
Non Linear System

Purpose – The purpose of this paper is to carry out a finite element simulation of a physically non-linear phase change problem in a two-dimensional space without adaptive remeshing or moving-mesh algorithms. The extended finite element method (XFEM) and the level set method (LSM) were used to capture the transient solution and motion of phase boundaries. It was crucial to consider the effects of unequal densities of the solid and liquid phases and the flow in the liquid region. Design/methodology/approach – The XFEM and the LSM are applied to solve non-linear transient problems with a phase change in a two-dimensional space. The model assumes thermo-dependent properties of the material and unequal densities of the phases; it also allows for convection in the liquid phase. A non-linear system of equations is derived and a numerical solution is proposed. The Newton-Raphson method is used to solve the problem and the LSM is applied to track the interface. Findings – The robustness and utility of the method are demonstrated on several two-dimensional benchmark problems. Originality/value – The novel procedure based on the XFEM and the LSM was developed to solve physically non-linear phase change problems with unequal densities of phases in a two-dimensional space.

FINITE-ELEMENT ENTHALPY METHOD FOR DISCRETE PHASE CHANGE

1986 ◽  
Vol 9 (4) ◽  
pp. 403-417 ◽  
Author(s):  
A. M. Cames-Pintaux ◽  
M. Nguyen-Lamba
Keyword(s):  
Finite Element ◽  
Phase Change ◽  
Enthalpy Method ◽  
Discrete Phase

scholarly journals Parallel finite-element codes for the simulation of two-dimensional and three-dimensional solid–liquid phase-change systems with natural convection

2020 ◽  
Vol 257 ◽  
pp. 107492
Author(s):  
Georges Sadaka ◽  
Aina Rakotondrandisa ◽  
Pierre-Henri Tournier ◽  
Francky Luddens ◽  
Corentin Lothodé ◽  
...  
Keyword(s):  
Finite Element ◽  
Natural Convection ◽  
Liquid Phase ◽  
Phase Change ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Parallel Finite Element ◽  
Solid Liquid

DNB Oscillatory Temperature and Thermal Stress Responses for Evaporator Tubes Based on Rivulet Model

1978 ◽  
Vol 100 (3) ◽  
pp. 424-431 ◽  
Author(s):  
C. L. Chu ◽  
J. M. Roberts ◽  
A. W. Dalcher
Keyword(s):  
Finite Element ◽  
Thermal Stress ◽  
Temperature Variation ◽  
Stress Responses ◽  
Thermal Model ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Dimensional Problem ◽  
Computer Codes ◽  
Oscillatory Temperature

Experiment evidence and observations have shown that the DNB oscillation phenomena can best be characterized by water rivulets motion with temperature variation in the circumferential direction. This paper presents the rivulet thermal model that directly corresponds to these observations. Finite element computer codes were used to evaluate temperature and thermal stress behavior of the steam tube under the condition where water rivulets appear and disappear along the tube inside circumference. An inherently complicated three-dimensional problem can reasonably be reduced to a two-dimensional analysis with relative simplicity.

Finite-Element Enthalpy Method for Discrete Phase Change

1986 ◽  
Vol 9 (4) ◽  
pp. 403-417
Author(s):  
A. M. Cames-Pintaux ◽  
M. Nguyen-Lamba
Keyword(s):  
Finite Element ◽  
Phase Change ◽  
Enthalpy Method ◽  
Discrete Phase

Three-Dimensional Structure of Cloned T3 Connector Protein at 1.6nm Resolution

1990 ◽  
Vol 48 (1) ◽  
pp. 282-283
Author(s):  
José L. Carrascosa ◽  
José M. Valpuesta ◽  
Hisao Fujisawa
Keyword(s):  
Dna Sequences ◽  
Expression Vector ◽  
Three Dimensional ◽  
Deae Cellulose ◽  
Dna Packaging ◽  
Dimensional Structure ◽  
Two Dimensional ◽  
Freezing And Thawing ◽  
Three Dimensional Structure ◽  
Dimensional Reconstruction

The head to tail connector of bacteriophages plays a fundamental role in the assembly of viral heads and DNA packaging. In spite of the absence of sequence homology, the structure of connectors from different viruses (T4, Ø29, T3, P22, etc) share common morphological features, that are most clearly revealed in their three-dimensional structure. We have studied the three-dimensional reconstruction of the connector protein from phage T3 (gp 8) from tilted view of two dimensional crystals obtained from this protein after cloning and purification.DNA sequences including gene 8 from phage T3 were cloned, into Bam Hl-Eco Rl sites down stream of lambda promotor PL, in the expression vector pNT45 under the control of cI857. E R204 (pNT89) cells were incubated at 42°C for 2h, harvested and resuspended in 20 mM Tris HC1 (pH 7.4), 7mM 2 mercaptoethanol, ImM EDTA. The cells were lysed by freezing and thawing in the presence of lysozyme (lmg/ml) and ligthly sonicated. The low speed supernatant was precipitated by ammonium sulfate (60% saturated) and dissolved in the original buffer to be subjected to gel nitration through Sepharose 6B, followed by phosphocellulose colum (Pll) and DEAE cellulose colum (DE52). Purified gp8 appeared at 0.3M NaCl and formed crystals when its concentration increased above 1.5 mg/ml.

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