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

subtracting data from different slices

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

Reply
 
LinkBack Thread Tools Display Modes
Old   July 9, 2012, 08:10
Question subtracting data from different slices
  #1
New Member
 
Lydia Schulze
Join Date: Jan 2012
Location: Karlsruhe, Germany
Posts: 18
Rep Power: 6
Lydia is on a distinguished road
Hello paraviewers!

For finding out the pressure difference in different heights in my model I would like to subtract the data of different slices from each other in my geometry. The slices have slightly different shapes.

Can anyone give my a hint how I can do that with paraview?
Your help is much appreciated !

Regards,
Lydia
Lydia is offline   Reply With Quote

Old   July 5, 2016, 09:32
Default
  #2
New Member
 
Marc Vogel
Join Date: Jul 2016
Posts: 1
Rep Power: 0
MarcPTV is on a distinguished road
Hey paraviewers! Hey Lydia!
I would like to do something similar, but different models at same slice position.
Do you or anybody else knows the answer?

Regards,
Marc
MarcPTV is offline   Reply With Quote

Old   July 15, 2016, 13:15
Default
  #3
New Member
 
Join Date: Apr 2015
Posts: 8
Rep Power: 3
Swempa is on a distinguished road
Hi Marc and Lydia,

This can be achieved in a couple of different ways, depending of what result you are looking for to compute. You can compute a visual scalar difference on the slice with a delta value, or just compute a number of the pressure difference that you are searching.

The later is more simple and if I understand you right is this what you are looking for. Below i give a brief explanation on the setup.

Start with making the two slices that you want to compare (e.g. inlet outlet).

Now you need to compute the average pressure on the slice. As far as I know is there at the moment no good function for this, but you can combine the following filters to achieve this (remember to use good naming of the calculator results to be able to distinguish them from each other).
1. Apply a calculator filter on the slice and compute the quantity of interest.
2. Add a "Integrate Variables" filter to the calculator (this value is integrated over area and needs to be divided by the area to gain the average).
3. Add a "CellDataToPointData" filter to the "Integrate Variables" filter (tic the "Pass Cell Data" box, this will enable you to divide the calculated value with the Area of the surface).
4. Add a Calculator filter where you can find your values of interest under "Scalars" and divide the two with each other to get the average quantity.

Perform the same routine for the second slice to get the second average value for the delta calculation.

Now you can group your last two calculators with the quantities that you want to use in the delta calculation by selecting them and adding the "Group Dataset" filter.

On this "Group Dataset" filter you can add the last calculator filter to compute the delta with your scalars.

Hope that this will work for you!

Cheers
Swempa
Swempa is offline   Reply With Quote

Reply

Tags
difference, slices, subtraction

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
【Help】"Error: Update_Time_Level: invalid data" Chen FLUENT 2 August 24, 2014 07:51
fluentMeshToFoam multidomain mesh conversion problem Attesz OpenFOAM Other Meshers: ICEM, Star, Ansys, Pointwise, GridPro, Ansa, ... 12 May 2, 2013 10:52
Problem in running ICEM grid in Openfoam Tarak OpenFOAM 6 September 9, 2011 17:51
CGNS vs Tecplot Data Format LWhitson2 Main CFD Forum 3 July 1, 2011 13:50
How to update polyPatchbs localPoints liu OpenFOAM Running, Solving & CFD 6 December 30, 2005 18:27


All times are GMT -4. The time now is 18:25.