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February 27, 2014, 06:46 
Problem with cell area calculation in a slice

#1 
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Join Date: Jun 2013
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Hello everybody,
I want to do some tumble evaluation of a cylinder flow. Therefor I need the area of each cell. So I'm trying to calculate the area of each cell in a slice of my cylinder geometry. I chose the filter Mesh Quality and set the "triangle" and "quad quality measure" to "area". The quality column of the resulting spreadsheet shows the area of each cell. I tested this method with some easy blockmesh geometry (square cross section) and it worked well. (I summed all values up and compared it with the area of the cross section) However it doesnt work for my clinder. The sum of the cell areas is too low. The problem is that the area of some quad cells is calculated to be 0. This goes for small and bigger cells and seems to be randomly. The area of the marked cell in the screen below is zero. Also most of the other big cells around it. But not all of them are calculated wrong. What I tried so far:  Other paraview version. Im using 3.10.1 and I tested it with 4.1.0 too. Result: Same problem...  I tried it with more triangles than in the screenshot below. Result: Only the area of the triangles was calculated. All the square areas were calculated to zero. I hope anyone got some idea what could be the problem. Thank you in advance! example.jpg 

March 1, 2014, 08:13 

#2 
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Bruno Santos
Join Date: Mar 2009
Location: Lisbon, Portugal
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Hi daniel87,
I've seen this issue in the past as well, although it wasn't forum related, so I haven't written anything on this topic yet. The problem was that the faces in the section cut weren't all pointing to the same direction, or that the order of the points was bad... or that squares simply couldn't be calculated. Problem is that I can't find a case where I can reproduce this. Can you please share a VTK file of the slice for which you need to calculate the areas? Best regards, Bruno
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March 6, 2014, 07:15 

#3 
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Hi Bruno,
Thank you for your reply! Im not really familiar with Paraview. Is it possible to export just the slice? Because Im not allowed to upload the whole geometry. 

March 6, 2014, 15:37 

#4 
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Bruno Santos
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Quick answer:
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November 21, 2014, 12:56 

#5 
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Damian B.
Join Date: Oct 2014
Location: Stuttgart, Germany
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Hello everyone,
I also dealing with this problem. I used the Paraview Quality filter to calculate the area of each cell in a defined slice (Fluent > Ensight Gold format), it works fine, except the calculation of polygon areas, the result is always 1. It seems there is a bug in the current Paraview rel. 4.01 or misunderstanding on my side, have anyone an idea ? Damian 

October 24, 2015, 16:18 

#6  
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Bruno Santos
Join Date: Mar 2009
Location: Lisbon, Portugal
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Greetings Damian,
I've had your question on my todo list and I've finally taken a look into this. The latest ParaView 4.4.0 documentation states that only the following shapes are supported: http://www.paraview.org/ParaView/Doc...shQuality.html Quote:
Best regards, Bruno 

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