How to monitor a CEL expression

Luca L · September 21, 2012, 07:18

Hi All,

I'm trying to monitor a CEL expression (drag) which varies within the domain.
I've set-up additional variable and monitor point as following:

ADDITIONAL VARIABLE: $Drag1
Option = Definition
Tensor Type = SCALAR
Units = [ ]
Variable Type = Unspecified
END

FLOW:
DOMAIN: domain1
FLUID MODELS:
ADDITIONAL VARIABLE: $Drag1
Additional Variable Value = $fDrag
Option = Algebraic Equation
END

MONITOR POINT: $MonitorDrag
Cartesian Coordinates =
X = [m]
Y = [m]
Z = [m]
Option = Cartesian Coordinates
Output Variables List = $fDrag
END

where $fDrag is the expression for the drag, initialised and calculated in Perl.

The problem is $fDrag is inside of a loop that produces $fDrag1, $fDrag2... $fDragn corresponding to the number of turbines, so this is a reason for errors.

Could anybody help on this?
Thanks.

Luca

mp121209 · September 22, 2012, 02:56

To monitor a variable you wouldn't use a variable expression, use expression one. In monitor point, select option expression, and enter your expression for the drag.

ghorrocks · September 24, 2012, 22:55

Do you want your perl to be evaluated once at the start of the simulation, or continuously during the run as it progresses? Perl is only evaluated once at the start of the run so only the first option is possible.

September 21, 2012, 07:18	How to monitor a CEL expression	#1
Luca L New Member L Join Date: Mar 2011 Posts: 6 Rep Power: 15	Hi All, I'm trying to monitor a CEL expression (drag) which varies within the domain. I've set-up additional variable and monitor point as following: ADDITIONAL VARIABLE: $Drag1 Option = Definition Tensor Type = SCALAR Units = [ ] Variable Type = Unspecified END FLOW: DOMAIN: domain1 FLUID MODELS: ADDITIONAL VARIABLE: $Drag1 Additional Variable Value = $fDrag Option = Algebraic Equation END MONITOR POINT: $MonitorDrag Cartesian Coordinates = X = [m] Y = [m] Z = [m] Option = Cartesian Coordinates Output Variables List = $fDrag END where $fDrag is the expression for the drag, initialised and calculated in Perl. The problem is $fDrag is inside of a loop that produces $fDrag1, $fDrag2... $fDragn corresponding to the number of turbines, so this is a reason for errors. Could anybody help on this? Thanks. Luca

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September 22, 2012, 02:56		#2
mp121209 New Member Trần Đình Thắng Join Date: Mar 2012 Location: Moscow Russia, Hanoi Vietnam Posts: 24 Rep Power: 14	To monitor a variable you wouldn't use a variable expression, use expression one. In monitor point, select option expression, and enter your expression for the drag.

September 24, 2012, 22:55		#3
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,854 Rep Power: 144	Do you want your perl to be evaluated once at the start of the simulation, or continuously during the run as it progresses? Perl is only evaluated once at the start of the run so only the first option is possible.