CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > FLOW-3D

Modelling Melting/Solidification

Register Blogs Members List Search Today's Posts Mark Forums Read

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   April 16, 2012, 08:25
Default Modelling Melting/Solidification
  #1
Member
 
Yang Yue
Join Date: Feb 2010
Location: Birmingham, UK
Posts: 36
Rep Power: 16
therockyy is on a distinguished road
Dear FLOW-3D users,

I know FLOW-3D can model heat transfer and solidification problem, so I was trying to run a simple model on this.

I put a simple cylinder bar (Al alloy) inside a Pyrex glass tube. The surface of the bar contacted with the interior surface of the glass tube and the top face of the bar was free surface. Then I applied a heat source on the external surface of the glass tube. The mesh contained the all objects. The objects were set to continuously heated from room temperature to the 1000 K. I set the cylinder bar as the fluid region in "Model Setup"-->"Initial".

Initially the bar was solid and the temperature gradient around the bar looked OK during heating. Once the temperature of the bar reached about 20 K above the solidus temperature of the alloy, there was convection inside some region of the bar, which was also good since part of the bar started to melt. However, when the whole body of the bar reached that temperature (not the liquidus temperature), the velocity vector inside the bar pointed to the same direction as the gravity force and in the next time step, the free surface broke up, which should be stable or showed curvature due to the surface tension.

Has anybody experienced similar problem when they run solidification module in FLOW-3D?

Thanks!

Yang
therockyy is offline   Reply With Quote

Old   April 16, 2012, 14:25
Default
  #2
Senior Member
 
michael barkhudarov
Join Date: Mar 2009
Location: Sante Fe, New Mexico, USA
Posts: 336
Rep Power: 18
MuxaB is on a distinguished road
Quote:
Originally Posted by therockyy View Post
Dear FLOW-3D users,

I know FLOW-3D can model heat transfer and solidification problem, so I was trying to run a simple model on this.

I put a simple cylinder bar (Al alloy) inside a Pyrex glass tube. The surface of the bar contacted with the interior surface of the glass tube and the top face of the bar was free surface. Then I applied a heat source on the external surface of the glass tube. The mesh contained the all objects. The objects were set to continuously heated from room temperature to the 1000 K. I set the cylinder bar as the fluid region in "Model Setup"-->"Initial".

Initially the bar was solid and the temperature gradient around the bar looked OK during heating. Once the temperature of the bar reached about 20 K above the solidus temperature of the alloy, there was convection inside some region of the bar, which was also good since part of the bar started to melt. However, when the whole body of the bar reached that temperature (not the liquidus temperature), the velocity vector inside the bar pointed to the same direction as the gravity force and in the next time step, the free surface broke up, which should be stable or showed curvature due to the surface tension.

Has anybody experienced similar problem when they run solidification module in FLOW-3D?

Thanks!

Yang
Looks like you are doing all right with the heat transfer part. Sounds like pressure is initially uniform. If that's true, try initializing a hydrostatic pressure. Also, it may help to limit the time step size to smooth out the transition from pure h/t to flow in the metal.

Finally, try increasing the drag coefficient, TSDRG, from the default of 1.0, which may be too small, to something like a 1000. This will also smooth out the start of the flow in the part.
MuxaB is offline   Reply With Quote

Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
error message cuteapathy CFX 14 March 20, 2012 07:45
Modelling unsteady 2D aerofoil drag xlxc34 Main CFD Forum 0 June 24, 2011 05:42
Advice on multi-phase flow modelling Martin Main CFD Forum 3 October 14, 2008 06:16
how to ensure that your modelling is correct rvndr Main CFD Forum 7 March 1, 2004 13:21
Computational Modelling of Vortex Separators May Lim Main CFD Forum 6 November 13, 1998 13:36


All times are GMT -4. The time now is 01:13.