Arithmetic mean of velocity (steady - state)

lentschi · January 10, 2011, 16:57

Hello,

I am using CFX 12.1 (in steady state mode)to simulate flow in hydraulic pumps.
Because of instable phenomena at the examine loadcases the steady - state solution does not really converge but fluctuates with an almost constant amplitude (=velocity at 1000 measurement points in a spiral case).
Now I want to calculate the arithmetic mean of these velocity values at the defined points for comparing with measurement values.Therefor I create a perl code to import the coordinates of these measurement points in CFX-Post, to calculate the velocities (probe(Var)@Point) at these points and to export the velocities (.csv chart).but now i need the arithmetic mean of the velocities vs. iteration-numbers to get a "correct" solution for comparing.
So how can I reach this (preferred in CFX Post 12.1)?

Thank you for your advice in advance.

regards markus

ghorrocks · January 10, 2011, 17:43

Surely you are not asking "how do I calculate an arithmetic mean"?

lentschi · January 10, 2011, 18:26

So how do I calculate an arithmetic mean of velocity vs. iteration number after steady state calculation in CFX-Post 12.1 at the desired measurement POINTS (no area/line)?

Any idea?i hope this is possible!

Regards Markus

ghorrocks · January 11, 2011, 07:18

You have the values at the points versus time, so stick it into excel/matlab/python/whatever and calculate an arithmetic mean. You cannot do this easily in CFD-Post.

January 10, 2011, 16:57	Arithmetic mean of velocity (steady - state)	#1
lentschi Member sirLentschi Join Date: Nov 2010 Posts: 87 Rep Power: 15	Hello, I am using CFX 12.1 (in steady state mode)to simulate flow in hydraulic pumps. Because of instable phenomena at the examine loadcases the steady - state solution does not really converge but fluctuates with an almost constant amplitude (=velocity at 1000 measurement points in a spiral case). Now I want to calculate the arithmetic mean of these velocity values at the defined points for comparing with measurement values.Therefor I create a perl code to import the coordinates of these measurement points in CFX-Post, to calculate the velocities (probe(Var)@Point) at these points and to export the velocities (.csv chart).but now i need the arithmetic mean of the velocities vs. iteration-numbers to get a "correct" solution for comparing. So how can I reach this (preferred in CFX Post 12.1)? Thank you for your advice in advance. regards markus

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January 10, 2011, 17:43		#2
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,850 Rep Power: 144	Surely you are not asking "how do I calculate an arithmetic mean"?

January 10, 2011, 18:26		#3
lentschi Member sirLentschi Join Date: Nov 2010 Posts: 87 Rep Power: 15	So how do I calculate an arithmetic mean of velocity vs. iteration number after steady state calculation in CFX-Post 12.1 at the desired measurement POINTS (no area/line)? Any idea?i hope this is possible! Regards Markus

January 11, 2011, 07:18		#4
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,850 Rep Power: 144	You have the values at the points versus time, so stick it into excel/matlab/python/whatever and calculate an arithmetic mean. You cannot do this easily in CFD-Post.