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

Line information

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

Reply
 
LinkBack Thread Tools Display Modes
Old   September 4, 2000, 09:08
Default Line information
  #1
Gert-Jan van der Gulik
Guest
 
Posts: n/a
Hi all,

Using CFX4.2, I want to know the average temperature over an arbitrary line in space (i.e. the average temperature between points x1,y1,z1 and x2,y2,z2). As I have 8 different cases and 98 different lines, there is a lot of work to be done and I want to do it as efficient as possible.

Which Post-processing program do you think is most efficient in performing this tedious work? Any suggestion?

I have checked the USERfortran routines but, as far as I know, there is no fancy routine to use. Does anyone have a routine or some tips and tricks to share?

Many thanks in advance,

Gert-Jan van der Gulik
  Reply With Quote

Old   September 4, 2000, 10:13
Default Re: Line information
  #2
Jan Rusås
Guest
 
Posts: n/a
Hi Gert-Jan,

I do not know if this solution is the most efficient, but anyway here it come.

You can use CFX-analyse

You must create a new region in the region manager,

Select physical and line, you can then define your line by x,y,z

It might be convenient to rename the line so it is easier to select the many different lines you are dealing with. You may copy this 'line' to another one and then adjust the x,y,z data and by that defining all your lines, or it might be more easy to change the data in the visualisation manager, it is up to you.

In the visualisation manager, you then select f.x. xy-graph and then the appropriate 'line' and scalar and write the data to a file.

The good thing about analyse is that you can define all your plots and then read in a new dump file and then just apply on each plot, he data will then be updated.

Regards Jan
  Reply With Quote

Old   September 4, 2000, 11:19
Default Re: Line information
  #3
Gert-Jan van der Gulik
Guest
 
Posts: n/a
Dear Jan,

Thanks for the quick reply but I can't find CFX-Analyse. I think CFX-Analyse is a MS-Windows-version feature that I don't use. We only have CFX-Visualise, CFX-view, Visualise-linegrapher and Linegraph. Probably I can use Visualise-linegrapher but yet I haven't figured out how it works.

Regards, Gert-Jan
  Reply With Quote

Old   September 4, 2000, 11:45
Default Re: Line information
  #4
Budi
Guest
 
Posts: n/a
Hi Gert,

It's me ;-) CFX-Analyse is a additional post-processor for CFX4.3 and later. IMO it's a better post-processor than visualiser. I don't know if it's available for Windows version but I'm sure AEAT has a SUN version. I have tried it on our SUN for a limited time and I can say.. I like it.

budi
  Reply With Quote

Old   September 5, 2000, 03:10
Default Re: Line information
  #5
Jan Rusås
Guest
 
Posts: n/a
Hi again Gert Jan,

I can not help you with Visualise and linegraph is for viewing data in a file already written by e.g. view. I do not know if Visualise-linegrapher is for the same purpose.

You can also create line data in view, but it is not so efficient as in analyse.

You should go to the define line window, there you define the line in physical space x,y,z. Go to write data- there you can select all variables or a single and select and file name. Note you can increase the number of points in one of the pop-up windows in the initializing, look out for maximum number of cells in a line. The problem with view is, it is not a efficient way of doing this, you have to define all your lines for each dump file, no information about the lines are saved when you read in a new dump file.

I do think you should try and see if Visualise could solve your problem, I also think, depending on how complicated you structure is, you should use user fortran for writing your data. If the line data you want does not fit with cell centres or faces the tricky part is only the interpolation.

Regards Jan
  Reply With Quote

Old   September 14, 2000, 03:58
Default Re: Line information
  #6
Jan Rusås
Guest
 
Posts: n/a
Dear Gert-Jan,

Just for your information, Line graph data is available through the command file in CFX4.3. An upgrade will very simple solve your problem.

Regards Jan
  Reply With Quote

Old   September 18, 2000, 03:17
Default Re: Line information
  #7
Gert-Jan van der Gulik
Guest
 
Posts: n/a
Jan,

'line graph data' was already available in CFX-4.2 and will only give temperature at a single point as a function of iteration or timestep (as far as I know). I don't see how this would provide an average temperature between (x1,y1,z1) and (x2,y2,z2).

Still looking for the most efficient route............................................. ............................Regards, Gert-Jan
  Reply With Quote

Old   September 18, 2000, 03:36
Default Re: Line information
  #8
Jan Rusås
Guest
 
Posts: n/a
Dear Gert,

My mistake, You are right line graph is only for a point, it should be named point graph. Several points will give you a line!, which you can average. Have you checked if it is possible in patch data to define a line. You should be able to use user fortran for your problem, i.e. usrsrc, as already mentioned. Depending on the structure of your mesh the only tricky part is the interpolation, which on the other hand is not so difficult.

Regards Jan

  Reply With Quote

Old   September 18, 2000, 03:53
Default Re: Line information
  #9
Gert-Jan van der Gulik
Guest
 
Posts: n/a
Dear Jan,

I know I should put some effort in userfortran but don't have the time as I have to write my PhD-thesis. For this thesis I need some average temperatures that should be very easy to get using CFX, but ........... well, you already know. I am also convinced there is someone out there in the world that faced the problem before. I don't see why I should re-event the wheel.

When I have the time I will write the fortran code and come back on this topic.... Anyway, thanks for the suggestion on CFX-Analyse. This programs helps, a little.

Regards, Gert-Jan
  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
erros in Allwmake jiwon OpenFOAM Installation 6 February 15, 2014 06:36
sample utility stops sampling once the line leaves the domain Zymon OpenFOAM 1 May 2, 2012 04:51
1.7.x Environment Variables on Linux 10.04 rasma OpenFOAM Installation 9 July 30, 2010 04:43
OpenFOAM15 installables are incomplete problem with paraFoam tryingof OpenFOAM Bugs 17 December 7, 2008 04:41
BlockMeshmergePatchPairs hjasak OpenFOAM Native Meshers: blockMesh 11 August 15, 2008 07:36


All times are GMT -4. The time now is 14:46.