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

Bounds error for an EOS specified via an interpolation table

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

Reply
 
LinkBack Thread Tools Display Modes
Old   November 11, 2012, 22:07
Default Bounds error for an EOS specified via an interpolation table
  #1
New Member
 
Join Date: Oct 2012
Posts: 8
Rep Power: 4
cfdonlineuser is on a distinguished road
I am having a problem solving a thermally driven convection problem where the fluid is liquid co2 is driven by thermal gradients in a deep vertical well. The problem solves quite well for constant properties but when the density is a variable function of pressure and temperature there is an error after the first time step. It's not time step size dependent. I use an interpolation user function for density in terms of pressure and temperature based on well known tables for liquid co2. The error is below. Obviously cfx thinks the derivative wrt pressure is invalid or too large. I've independently checked at the derivative and it's pretty linear. I've turned off buoyancy and the problem still persists

Any suggestions how to resolve this problem. Any way to interrogate this interpolation user function ie calculate the derivative wrt pressure ?

---------

*Fatal bounds error detected
*---------------------------
*Variable: Density Derivative wrt Pressure at Constant Temperature
*Locale *: CO2 WATER Domain

+--------------------------------------------------------------------+
| ERROR #001100279 has occurred in subroutine ErrAction. ************|
| Message: ************************************************** ********|
| Stopped in routine ENFORCE_BOUNDS *********************************
cfdonlineuser is offline   Reply With Quote

Old   November 12, 2012, 03:50
Default
  #2
New Member
 
Join Date: Oct 2012
Posts: 8
Rep Power: 4
cfdonlineuser is on a distinguished road
just an update to this thread, as I figured out what the problem was. I simply reordered the table so that pressure varies first then temperature in the table T,P,density.The error occurs when temperature varies first, which seems to me very arbitrary.
cfdonlineuser is offline   Reply With Quote

Reply

Thread Tools
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 On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
bounds error jai CFX 3 July 3, 2014 06:03
Help on 2D interpolation in StarCCM+ madhuri CD-adapco 0 November 3, 2010 15:21
Surface interpolation schemes and parallelization jutta OpenFOAM Running, Solving & CFD 0 February 25, 2010 15:32
momentum interpolation for collocated grid Hadian Main CFD Forum 4 December 25, 2009 08:25
Table Manipulation furkan CD-adapco 0 April 4, 2006 10:23


All times are GMT -4. The time now is 06:51.