Force and torque evaluation

Jiricbeng · July 18, 2016, 10:01

Hello,

in CFD POST, I cant evaluate torque and force on a few faces, I receive error:

ERROR:
Flow data - vertex count mismatch

other evaluation works on these faces, such as area average pressure, temperature etc.

??????????

ghorrocks · July 18, 2016, 20:35

I have never seen that error before. There must be something very strange about the face you are doing this to.

Jiricbeng · July 21, 2016, 04:16

Yes it is very strange. I tried to evaluate Area Integral of Pressure on given surface in X direction as well as Wall shear and it works! Obviously I would be able to evaluate the forces on the basis of these surface integrals.
But I need to evaluate torque as well. However to create my own expression to evaluate torque to an axis of my local coordinate system seems to be a difficult task.

jojo911 · June 29, 2017, 05:14

Hello,

can anyone help me?
I have the same error.

Thanks

Ethan_Sparkle · July 28, 2017, 06:36

Hi, I also met the same problem. very strange. I used local parallel in CFX when solving my problem. The results are then evaluated in CFDPost. I used the exactly same .def file with several different partition number, then I met the problem for some of them. Have no idea about this.

CsabiH · September 4, 2019, 10:29

Hi,
I have the same issue. I tried with simplified simulation and it's works (2D cases and rotating a "brick"), the CFX/CFD-Post can make the a chart for this simple cases... So I have still the CFD-Post error (ERROR Flow data - vertex count mismatch.) for my real case, but I can have my results.

I made a monitor for my tourqe expressions and from the solver I export my results. (see the attached image)

July 18, 2016, 10:01	Force and torque evaluation	#1
Jiricbeng Senior Member Jiri Join Date: Mar 2014 Posts: 218 Rep Power: 13	Hello, in CFD POST, I cant evaluate torque and force on a few faces, I receive error: ERROR: Flow data - vertex count mismatch other evaluation works on these faces, such as area average pressure, temperature etc. ??????????

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July 18, 2016, 20:35		#2
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,703 Rep Power: 143	I have never seen that error before. There must be something very strange about the face you are doing this to.

July 21, 2016, 04:16		#3
Jiricbeng Senior Member Jiri Join Date: Mar 2014 Posts: 218 Rep Power: 13	Yes it is very strange. I tried to evaluate Area Integral of Pressure on given surface in X direction as well as Wall shear and it works! Obviously I would be able to evaluate the forces on the basis of these surface integrals. But I need to evaluate torque as well. However to create my own expression to evaluate torque to an axis of my local coordinate system seems to be a difficult task.

June 29, 2017, 05:14		#4
jojo911 New Member Join Date: Jun 2017 Posts: 3 Rep Power: 8	Hello, can anyone help me? I have the same error. Thanks

July 28, 2017, 06:36		#5
Ethan_Sparkle Member Join Date: Dec 2016 Posts: 31 Rep Power: 0	Hi, I also met the same problem. very strange. I used local parallel in CFX when solving my problem. The results are then evaluated in CFDPost. I used the exactly same .def file with several different partition number, then I met the problem for some of them. Have no idea about this.