The integrate variables filter does not compute an average. It integrates the variables over a surface/volume. To calculate a (weighted) average, you have to divide by the area/volume. If the result is still off, let me know - I can investigate if there is a bug.
-berk On Wed, Aug 5, 2009 at 4:09 PM, Wei Wu<[email protected]> wrote: > Dear Tobias, > > Many thanks for your help. > > Do you think it is necessary to extract the sub-domain, on which I want to > calculate average value, previous to using the integrate filter? > > I am so sorry that I am still confused about the integrate filter. For > example, I have a result, in which temperatures are in the range 20 ~ 39.5 > degree C. After I apply the integrate filter, I got the temperature value is > 0.00210551, which is so small. I multiply this value with the cell number, > 23040, I got 48.5109504, which is beyond the range. > > You did mention I have to multiply this averaged value with the calculated > area value to produce proper values. I feel sorry that I don't truly > understand this. In my example, the area/volume is very small. They are at > the level 0.01/0.001. Therefore 0.00210551 times total area/volume cannot > give a reasonable temperature either. I feel quite confused. > > Many thanks in advance for your further help. > > Regards, Wei > > Quoting Tobias Froebel <[email protected]>: > >> Hello Wei, >> >> I'm using the Integrate Filter to calculate area- and mass-averaged flow >> values in planar polydata grids (boundary surfaces) of cfd-models. >> >> It's important to convert point-data to cell-data previous to applying >> the integrate variables filter. After applying this filter you receive >> area averaged values of every cell-data. Therefore in my case you would >> have to multiply the averaged value (for example averaged temperature) >> with the although calculated area value to receive "proper" temperature >> values. >> >> I've never tried to apply the integrate filter on 3D volume data, but I >> expect volume averaged results, therefore multiplying with the volume >> value should give you more meaningful values. >> >> Tobias >> >> -- >> Dipl.-Ing. Tobias Fröbel / CFD >> >> Institute for Flight Propulsion / TU Munich >> >>> Message: 2 >>> Date: Wed, 5 Aug 2009 12:01:19 +0100 >>> From: "Wei Wu" <[email protected]> >>> Subject: [Paraview] Average value on specific sub-domains >>> To: <[email protected]> >>> Message-ID: >>> <002401ca15bc$0fee9790$2fcbc6...@[email protected]> >>> Content-Type: text/plain; charset="utf-8" >>> >>> Dear all, >>> >>> I am from Manchester, UK and I am new to CFD calculations. I am using >>> Code_Saturne(http://code-saturne.blogspot.com) /FVM method to produce data >>> in EnSight format and then checking it in ParaView. An illustration is >>> attached. I am working on coolant oil flow and so the picture shows a matrix >>> of oil flow ducts. This is a 2D model with structured rectangular mesh grid, >>> but the mesh density is not uniform. >>> >>> In order to compare with results from my lumped parameter models, I have >>> to investigate average values of parameters (the most important one of these >>> is temperature) on specific sub-domains, as framed out in the picture. I >>> found a solution >>> (http://www.paraview.org/pipermail/paraview/2008-April/007882.html) and >>> tried the filter "integrate variables", but found the result doesn't seem to >>> be reasonable. I guess I must did something wrong. >>> >>> I am quite interested in the extension script by python. Because my model >>> is constructed by basic geometric elements, and the number of the elements >>> is growing along with my progress, I am thinking about using python to >>> obtain average values for all of the sub-domains in a loop. If I can access >>> information of all the cells in a specific sub-domain (I can compute >>> coordinate of these domains first), including rectangular cells' sides and >>> areas as well as the corresponding cell values (temperature, pressure, >>> velocity etc), I guess it is not difficult to derive average values for all >>> of the sub-domains. >>> >>> I know a little about python and have experience on programming. I looked >>> up ParaView Wiki, tried some python samples, but unfortunately I still don't >>> know how to start to implement my idea. Is there a detailed API functions >>> manual existing? Or could you please give some hints or examples to help? >>> >>> Thank you very much for your help about this. >>> >>> Best regards, >>> Wei >>> -------------- next part -------------- >>> A non-text attachment was scrubbed... >>> Name: ducts_sample.PNG >>> Type: image/png >>> Size: 36866 bytes >>> Desc: not available >>> URL: >>> <http://www.paraview.org/pipermail/paraview/attachments/20090805/70105434/attachment.png >>> >> _______________________________________________ >> Powered by www.kitware.com >> >> Visit other Kitware open-source projects at >> http://www.kitware.com/opensource/opensource.html >> >> Please keep messages on-topic and check the ParaView Wiki at: >> http://paraview.org/Wiki/ParaView >> >> Follow this link to subscribe/unsubscribe: >> http://www.paraview.org/mailman/listinfo/paraview >> > > > _______________________________________________ > Powered by www.kitware.com > > Visit other Kitware open-source projects at > http://www.kitware.com/opensource/opensource.html > > Please keep messages on-topic and check the ParaView Wiki at: > http://paraview.org/Wiki/ParaView > > Follow this link to subscribe/unsubscribe: > http://www.paraview.org/mailman/listinfo/paraview > _______________________________________________ Powered by www.kitware.com Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html Please keep messages on-topic and check the ParaView Wiki at: http://paraview.org/Wiki/ParaView Follow this link to subscribe/unsubscribe: http://www.paraview.org/mailman/listinfo/paraview
