scholarly journals Calculation of Phase-Change Boundary Position in Continuous Casting

2013 ◽  
Vol 13 (4) ◽  
pp. 57-62 ◽  
Author(s):  
A.A. Ivanova
Keyword(s):  
Phase Change ◽  
Solid Phase ◽  
Nonlinear Partial Differential Equations ◽  
Heat Transfer Process ◽  
Method Of Calculation ◽  
Boundary Position ◽  
System Equations ◽  
Stefan Condition ◽  
Non Linear System ◽  
The Mathematical Model

Abstract The problem of determination of the phase-change boundary position at the mathematical modeling of continuous ingot temperature field is considered. The description of the heat transfer process takes into account the dependence of the thermal physical characteristics on the temperature, so that the mathematical model is based on the nonlinear partial differential equations. The boundary position between liquid and solid phase is given by the temperatures equality condition and the Stefan condition for the two-dimensional case. The new method of calculation of the phase-change boundary position is proposed. This method based on the finite-differences with using explicit schemes and on the iteration method of solving of non-linear system equations. The proposed method of calculation is many times faster than the real time. So that it amenable to be used for model predictive control of continuous semifinished product solidification.

Energy Storage With Solid/Liquid Phase Change in Presence of Natural Convection

2001 ◽  
Author(s):  
M. Pinelli ◽  
S. Piva
Keyword(s):  
Natural Convection ◽  
Energy Storage ◽  
Liquid Phase ◽  
Phase Change ◽  
Change Process ◽  
Solid Phase ◽  
High Energy ◽  
Heat Transfer Process ◽  
Phase Change Process ◽  
Solid Liquid

Abstract Solid/liquid phase change process has received great attention for its capability to obtain high energy storage efficiency. In order to analyse these systems, undergoing a solid/liquid phase change, in many situations the heat transfer process can be considered conduction-dominated. However, in the past years, it has been shown that natural convection in the liquid phase can significantly influence the phase change process in terms of temperature distributions, interface displacement and energy storage. In this paper, a procedure to analyse systems undergoing liquid/solid phase change in presence of natural convection in the liquid phase based on the utilisation of a commercial computer code (FLUENT), has been developed. This procedure is applied to a cylinder cavity heated from above and filled with a Phase Change Material. It was found that when the coupling with the environment, even if small, is considered, natural convection in the liquid phase occurs. The numerical results are then compared with available experimental data. The analysis shows that the agreement between numerical and experimental results is significantly improved when the results are obtained considering the presence of circulation in the liquid phase instead of considering the process only conduction-dominated. Furthermore, some interesting features of the flow field are presented and discussed.

Solid/Liquid Phase Change in Presence of Natural Convection: A Thermal Energy Storage Case Study

2003 ◽  
Vol 125 (3) ◽  
pp. 190-198 ◽  
Author(s):  
M. Pinelli ◽  
S. Piva
Keyword(s):  
Natural Convection ◽  
Energy Storage ◽  
Liquid Phase ◽  
Phase Change ◽  
Change Process ◽  
Solid Phase ◽  
High Energy ◽  
Heat Transfer Process ◽  
Phase Change Process ◽  
Solid Liquid

Solid/liquid phase change process has received great attention for its capability to obtain high energy storage efficiency. In order to analyze these systems, undergoing a solid/liquid phase change, in many situations the heat transfer process can be considered conduction-dominated. However, in the past years, it has been shown that natural convection in the liquid phase can significantly influence the phase change process in terms of temperature distributions, interface displacement and energy storage. In this paper, a procedure to analyze systems undergoing liquid/solid phase change in presence of natural convection in the liquid phase based on the utilisation of a commercial computer code (FLUENT), has been developed. This procedure is applied to the study of a cylinder cavity heated from above and filled with a phase change material. It was found that when the coupling with the environment, even if small, is considered, natural convection in the liquid phase occurs. The numerical results are then compared with available experimental data. The analysis shows that the agreement between numerical and experimental results is significantly improved when the results are obtained considering the presence of circulation in the liquid phase instead of considering the process only conduction-dominated. Furthermore, some interesting features of the flow field are presented and discussed.

CONTROL OF HEAT RELEASE ENERGY DURING HEATING FROM SOLID-SOLID PHASE CHANGE MATERIAL

2018 ◽  
Author(s):  
Ryohei Gotoh ◽  
Tsuyoshi Totani ◽  
Masashi Wakita ◽  
Harunori Nagata
Keyword(s):  
Phase Change ◽  
Heat Release ◽  
Phase Change Material ◽  
Solid Phase ◽  
Change Material

Biodegradable Polyurethane Solid‐Solid Phase Change Materials

2021 ◽  
Vol 6 (24) ◽  
pp. 6280-6285
Author(s):  
Burcu Oktay ◽  
Nilhan Kayaman‐Apohan
Keyword(s):  
Phase Change ◽  
Phase Change Materials ◽  
Solid Phase ◽  
Biodegradable Polyurethane

Room temperature rectification in tapered-channel thermal diodes through nanoscale confinement-induced liquid–solid phase change

2021 ◽  
Vol 129 (7) ◽  
pp. 075103
Author(s):  
Matt Jacobs ◽  
Xinran Zhou ◽  
Edgar Olivera ◽  
Ryan Sheil ◽  
Shu Huang ◽  
...  
Keyword(s):  
Phase Change ◽  
Room Temperature ◽  
Solid Phase ◽  
Tapered Channel

Electrospun Polyethylene Glycol/Polyvinyl Alcohol Composite Nanofibrous Membranes as Shape-Stabilized Solid–Solid Phase Change Materials

2020 ◽  
Vol 2 (3) ◽  
pp. 167-177 ◽  
Author(s):  
Junwen Huang ◽  
Houyong Yu ◽  
Somia Yassin Hussain Abdalkarim ◽  
Jaromir Marek ◽  
Jiri Militky ◽  
...  
Keyword(s):  
Polyethylene Glycol ◽  
Polyvinyl Alcohol ◽  
Phase Change ◽  
Phase Change Materials ◽  
Solid Phase ◽  
Nanofibrous Membranes

Optimization of thermal conductivity in composites loaded with the solid-solid phase-change materials

2018 ◽  
Vol 25 (6) ◽  
pp. 1157-1165
Author(s):  
Taoufik Mnasri ◽  
Adel Abbessi ◽  
Rached Ben Younes ◽  
Atef Mazioud
Keyword(s):  
Thermal Conductivity ◽  
Phase Change ◽  
Phase Change Materials ◽  
Solid Phase ◽  
Spherical Inclusions ◽  
First Case ◽  
The Matrix ◽  
Composite Conductivity ◽  
First Time

AbstractThis work focuses on identifying the thermal conductivity of composites loaded with phase-change materials (PCMs). Three configurations are studied: (1) the PCMs are divided into identical spherical inclusions arranged in one plane, (2) the PCMs are inserted into the matrix as a plate on the level of the same plane of arrangement, and (3) the PCMs are divided into identical spherical inclusions arranged periodically in the whole matrix. The percentage PCM/matrix is fixed for all cases. A comparison among the various situations is made for the first time, thus providing a new idea on how to insert PCMs into composite matrices. The results show that the composite conductivity is the most important consideration in the first case, precisely when the arrangement plane is parallel with the flux and diagonal to the entry face. In the present work, we are interested in exploring the solid-solid PCMs. The PCM polyurethane and a wood matrix are particularly studied.

A Novel Solid-Solid Phase Change Material Based on Poly(styrene-co-acrylonitrile) Grafting With Palmitic Acid Copolymers

2015 ◽  
Vol 52 (8) ◽  
pp. 617-624 ◽  
Author(s):  
Siyang Mu ◽  
Jing Guo ◽  
Chunfang Yu ◽  
Yuanfa Liu ◽  
Yumei Gong ◽  
...  
Keyword(s):  
Palmitic Acid ◽  
Phase Change ◽  
Phase Change Material ◽  
Solid Phase ◽  
Change Material
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