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

can i use field functions in star ccm for this?

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   October 4, 2007, 07:23
Default can i use field functions in star ccm for this?
  #1
stu
Guest
 
Posts: n/a
Hi,

I am modelling a number of bio-heat sources confined in a room.

I want each each source to respond to local air velocity and temperature conditions by regulating heat flux, i.e. thermoregulation.

If I have a simple equation to describes this response, can I prescribe it as a heat flux boundary condition with the use of field functions, or must I attempt some user coding.

Also would I need to run a transient simulation.

Looking forward to any suggestions, Regards, stu
  Reply With Quote

Old   October 8, 2007, 20:59
Default Re: can i use field functions in star ccm for this
  #2
Aeron
Guest
 
Posts: n/a
This should be possible in STAR-CCM+ using field functions. Review the help section in CCM+ for examples on field functions. Set up a few easy ones as models, for example, start with pressure at the surface (velocity won't work for this) and tie the pressure to some factor of cooling or rate of heat transfer. Field functions examples are often only single lines. However, it may not be clear in their examples, but they can be nested into multiple loops. Or generate several stand-alone field functions based on others you have made. This is a little more cumbersome, but it still gets the job done.

Something else to consider is to create a geometry where the bio sources are solids, except for a small sphere or cube subtracted from inside the solid. The boundary created by subtracting the sphere can used as your source, then the solid heats/cools based on the internal boundary and the airflow going over the outside. If the value at the inside of the hollow (located inside the solid bio object, animal, plant, etc. whatever it is) is a good starting condition, then this approach is the more physical one.

  Reply With Quote

Old   October 12, 2007, 15:50
Default Thanks Aeron; I have one more question
  #3
stu
Guest
 
Posts: n/a
Thanks Aeron for your interesting suggestions,

I have did what you said and designed a hollow sphere; however I'd like its thermal conductivity to vary as a function of local temperature.

Is it possible to use field functions to reference a suitable cell, or group of cells for this temperature, i.e. an average temperature taken from a group of cells in the ambient, a little away from influence of the heat source.

There is very little documentation on user defined field functions, and none on nested loops, which I'd find helpful.

BTW, thanks for your very helpful comment
  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
postprocessing - TauW in custom field functions Ianto FLUENT 1 September 29, 2011 11:59
custom field functions Nuray FLUENT 0 May 31, 2006 14:34
Custom Field Functions bov FLUENT 5 November 21, 2005 08:31
Custom field functions sivakumar FLUENT 1 October 12, 2001 06:36
Custom Field Functions ak FLUENT 2 October 8, 2001 10:23


All times are GMT -4. The time now is 07:59.