Dear all, I'm looking for discussion and collaboration about melting and solidification problems. i'm intersting first on numerical resolution. discretisation schema. numeriacl thechniques and codes thank you

The first thing you need to tell us is:

1) whether you are working in a multicomponent system, as these will have a 'mushy zone' between regions of solid and melt. Latent heat is accounted across a range of temperatures.

2) is natural convection important,and if so, is it double-diffusive convection as compositional effcts often dominate in phase change

3) are you interested in the multiphase problem or is mixture theory, where each phase has the same local velocity, sufficient

There is an enormous amount of literature out there, whole books on these subjects. The moving boundary and density change issues make these difficult problems, and one must understand these before deciding on a best approach.

you may want to look at these references, which correspond to benchmark solutions

\bibitem[A34]{pub34} O. Bertrand, B. Binet, H. Combeau, S. Couturier, Y. Delannoy, D. Gobin, M. Lacroix, P. Le Qu\'er\'e, M. M\'edale, J. Mencinger, H. Sadat, G. Vieira\\ Melting driven by natural convection. A comparison exercise : first results\\ Int. J. Thermal Sciences, 1999, 38, 1, 5-26

\bibitem[A35]{pub35} P. Le Qu\'er\'e et D. Gobin\\ A note on possible flow instabilities in melting from the side\\ Int. J. Thermal Sciences, 1999, 38, 7, 595-600

\bibitem[A36]{pub36} D. Gobin et P. Le Qu\'er\'e \\ Melting from an isothermal wall. Synthesis of a numerical comparison exercice.\\ Computer Assisted Mechanics and Engineering Sciences, 2000, 7, 289-306

Dear George, I would like to clarify some points: In my work on the melting and solidification problems, I'm interested to the binary alloy, that's the phase change take place in a Marge of temperature and the mushy zone is modelled as a porous media. The natural convection plays an important key in my study. In order to validate my code I'm trying to examine the melting of pure materials where the benchmark solutions are available. The mathmatique formulation that I have used is based on the volume averaging technique. I should be happy to discuss with you Thanks

These references might be interesting:

@ARTICLE(Prakash1990, AUTHOR = "C. Prakash", TITLE = "Two-Phase Model for binary solid-liquid phase change. Part I: Governing equations", PAGES = "131-145", JOURNAL = NHT , YEAR = 1990, VOLUME = 18)

@ARTICLE(Voller1980, AUTHOR = "V.R. Voller and M. Gross", TITLE = " Accurate Solutions of Moving Boundary Problems Using the Enthalpy Method", PAGES = "545-556", JOURNAL = IJHMT , YEAR = 1980, VOLUME = 24)

@ARTICLE(Voller1990, AUTHOR = "V.R. Voller and C. R. Swaminathan", TITLE = "Fixed Grid Techniques for Phase Change Problems: A Review", PAGES = "875-898", JOURNAL = IJNME , YEAR = 1990, VOLUME = 30)

@ARTICLE(Voller1993, AUTHOR = "V.R. Voller", TITLE = "The modelling of heat, mass and solute transport in solidification systems", JOURNAL = IJNME , YEAR = 1989, PAGES = "189-206", VOLUME = 32)

@string{NHT = "Numerical Heat Transfer, Part B"} @string{JHT = "Journal of Heat Transfer"} @string{IJHMT = "International Journal of Heat and Mass Transfer"} @string{JCP = "Journal of Computational Physics"} @string{IJNME = "International Journal for Numerical Methods in Engineering"}

May I humbly direct you to one my own papers that deal with all these issues? In it we address variable enthalpy-temperature relationships, a rather complex rheological model for the mush-to-suspension transition and both compositional and thermal buoyancy.

Barboza & Bergantz, 1997, "Melt productivity and rheology: Complementary inflences on progress of melting", Numerical Heat Transfer, part A, v. 31, p. 375-392.

The mixture model approach that is implicit in this and many other formulation of the phase change problem are ultimately not very satisfying unless you have vanishing Stokes number and hence all phases have the same local velocity. I have subsequently switched to a full multiphase approach working with my colleague Jun Ni. His work still stands as recommended reading:

Ni and Berkermann, 1991, "A volume-averaged two-phase model for transport phenomena during solidification", Metall. Trans. B, v. 22B, p. 349-361.

[RAHULME]

Originally Posted by George Bergantz
;13367

May I humbly direct you to one my own papers that deal with all these issues? In it we address variable enthalpy-temperature relationships, a rather complex rheological model for the mush-to-suspension transition and both compositional and thermal buoyancy.

Barboza & Bergantz, 1997, "Melt productivity and rheology: Complementary inflences on progress of melting", Numerical Heat Transfer, part A, v. 31, p. 375-392.

The mixture model approach that is implicit in this and many other formulation of the phase change problem are ultimately not very satisfying unless you have vanishing Stokes number and hence all phases have the same local velocity. I have subsequently switched to a full multiphase approach working with my colleague Jun Ni. His work still stands as recommended reading:

Ni and Berkermann, 1991, "A volume-averaged two-phase model for transport phenomena during solidification", Metall. Trans. B, v. 22B, p. 349-361.

if there is vertical tube heated from inner side then how to simulate melting process in th tube

[RAHULME]

can anybody please tell me process of simulating melting of paraffin wax into tube in tube type LTES.considering problem 2D and if possible 3D
please somebody help..
abhi_sutar123@yahoo.co.in

[CFDtoy]

Hello,
I dont see whats hard to set up here. Create your 2D/3D boundary with "inner heating elements" and set the relevant thermal boundary condition - temp on the inner walls, heat flux specified etc and activate solidification/melting module in whichever software. you only need to make sure that the crystallization temp is correctly specified in the relevant panel.

Paraffin wax or other metals, it doesnt matter, check for the correct properties in manuals, journals or books and input them. i will be careful in specifying conductivity and cp since k controls rate of cooling and Cp will make a diff in latent heat consumption (how fast solid -> melted wax).

Viscosity and other items are important to watch out for the flow field which in turn will affect convection and hence the heat transfer rates.

Good luck.

/CFDtoy

Originally Posted by RAHULME

can anybody please tell me process of simulating melting of paraffin wax into tube in tube type LTES.considering problem 2D and if possible 3D
please somebody help..
abhi_sutar123@yahoo.co.in

[Tushar_Telmasre]

Originally Posted by Sebastien Perron
;13341

These references might be interesting:

@ARTICLE(Prakash1990, AUTHOR = "C. Prakash", TITLE = "Two-Phase Model for binary solid-liquid phase change. Part I: Governing equations", PAGES = "131-145", JOURNAL = NHT , YEAR = 1990, VOLUME = 18)

@ARTICLE(Voller1980, AUTHOR = "V.R. Voller and M. Gross", TITLE = " Accurate Solutions of Moving Boundary Problems Using the Enthalpy Method", PAGES = "545-556", JOURNAL = IJHMT , YEAR = 1980, VOLUME = 24)

@ARTICLE(Voller1990, AUTHOR = "V.R. Voller and C. R. Swaminathan", TITLE = "Fixed Grid Techniques for Phase Change Problems: A Review", PAGES = "875-898", JOURNAL = IJNME , YEAR = 1990, VOLUME = 30)

@ARTICLE(Voller1993, AUTHOR = "V.R. Voller", TITLE = "The modelling of heat, mass and solute transport in solidification systems", JOURNAL = IJNME , YEAR = 1989, PAGES = "189-206", VOLUME = 32)

@string{NHT = "Numerical Heat Transfer, Part B"} @string{JHT = "Journal of Heat Transfer"} @string{IJHMT = "International Journal of Heat and Mass Transfer"} @string{JCP = "Journal of Computational Physics"} @string{IJNME = "International Journal for Numerical Methods in Engineering"}

@ARTICLE(Voller1993, AUTHOR = "V.R. Voller", TITLE = "The modelling of heat, mass and solute transport in solidification systems", JOURNAL = IJNME , YEAR = 1989, PAGES = "189-206", VOLUME = 32)

Hi, have you replicated this paper using fluent. I've been trying it since some time but till now not able to do so. Can anybody please help. I believe I am very close and stuck because of some very simple things.

Anticipating a positive reply..