pressure value out of domain!

feizaghaee · July 26, 2013, 08:34

I'm simulating a weir in a channel. I want to read pressure in some specific points. I draw a line with "cut" option then I read pressure at the first point of the line but I noticed that there are some pressure values below this point out of the domain. How is it possible?! what's the problem?

ghorrocks · July 27, 2013, 07:26

The cut option is giving you a value at every point that curve cuts a control volume boundary face.

feizaghaee · July 27, 2013, 16:22

Quote:

Originally Posted by ghorrocks

The cut option is giving you a value at every point that curve cuts a control volume boundary face.

I know that but I can also read pressure values by probe tool. how is it possible to exist values for pressure out of domain?!

ghorrocks · July 28, 2013, 07:43

It is interpolating from the control volume points to the locations you are specifying. The interpolation is not perfect and can result in locally strange results.

mjgraf · July 28, 2013, 10:41

alternative is to create a contour on X, Y, Z, or theta on a plane or iso surface. If this gives a contour line where you are interested, create a polyline from this contour line and see if the problem remains.
or create a polyline from a boundary intersection.

feizaghaee · July 29, 2013, 03:30

thank you all.

July 26, 2013, 08:34	pressure value out of domain!	#1
feizaghaee Senior Member moein Join Date: Dec 2009 Posts: 132 Rep Power: 16	I'm simulating a weir in a channel. I want to read pressure in some specific points. I draw a line with "cut" option then I read pressure at the first point of the line but I noticed that there are some pressure values below this point out of the domain. How is it possible?! what's the problem?

July 28, 2013, 07:43		#4
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,703 Rep Power: 143	It is interpolating from the control volume points to the locations you are specifying. The interpolation is not perfect and can result in locally strange results. feizaghaee likes this.

July 28, 2013, 10:41		#5
mjgraf Senior Member Join Date: Dec 2009 Posts: 131 Rep Power: 19	alternative is to create a contour on X, Y, Z, or theta on a plane or iso surface. If this gives a contour line where you are interested, create a polyline from this contour line and see if the problem remains. or create a polyline from a boundary intersection. feizaghaee likes this.

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July 27, 2013, 07:26		#2
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,703 Rep Power: 143	The cut option is giving you a value at every point that curve cuts a control volume boundary face.

July 29, 2013, 03:30		#6
feizaghaee Senior Member moein Join Date: Dec 2009 Posts: 132 Rep Power: 16	thank you all.