SU2 Dimensional Forces/Moments

bndrylyr · December 16, 2023, 16:38

Is there a way to have SU2 report dimensional forces and moments? If not, what is the reference moment? This does not appear to be explicitly documented on the website, but for forces it seems straightforward enough:

$\bar{F} = \bar{C}_F\cdot F_{ref}$

But there is no reference moment (that I'm aware of). Is the reference moment simply the product of the reference force and reference length, such that:

$\bar{M} = \bar{C}_M\cdot F_{ref}\cdot l_{ref}$

Thanks!

pcg · December 25, 2023, 15:17

That is correct, the reference length is what you specify in the config, the default is 1m.
The value of the reference force is called REFERENCE_FORCE in the history and screen output.
It is part of the AERO_COEFF history group.

bndrylyr · January 5, 2024, 01:36

Thank you!

Bakhshi · January 11, 2024, 07:44

Hello

I also had some doubts regarding reference values used in SU2.

I am analyzing force and moment by HISTORY_OUTPUT= (MOMENT_Y, FORCE_Y). Are these values non-dimensional? Since there is no unit displayed in first row (title row) in history.csv file produced.

If I want to see dimensional values of forces and moment, how can I see it?

Currently I have length_ref=0.1 and area_ref=0.

December 16, 2023, 16:38	SU2 Dimensional Forces/Moments	#1
bndrylyr New Member Join Date: Mar 2017 Posts: 5 Rep Power: 9	Is there a way to have SU2 report dimensional forces and moments? If not, what is the reference moment? This does not appear to be explicitly documented on the website, but for forces it seems straightforward enough: $\bar{F} = \bar{C}_F\cdot F_{ref}$ But there is no reference moment (that I'm aware of). Is the reference moment simply the product of the reference force and reference length, such that: $\bar{M} = \bar{C}_M\cdot F_{ref}\cdot l_{ref}$ Thanks!

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December 25, 2023, 15:17		#2
pcg Senior Member Pedro Gomes Join Date: Dec 2017 Posts: 466 Rep Power: 14	That is correct, the reference length is what you specify in the config, the default is 1m. The value of the reference force is called REFERENCE_FORCE in the history and screen output. It is part of the AERO_COEFF history group.

January 5, 2024, 01:36		#3
bndrylyr New Member Join Date: Mar 2017 Posts: 5 Rep Power: 9	Thank you!

January 11, 2024, 07:44		#4
Bakhshi New Member Bakhshi Mehul Join Date: Mar 2023 Posts: 5 Rep Power: 3	Hello I also had some doubts regarding reference values used in SU2. I am analyzing force and moment by HISTORY_OUTPUT= (MOMENT_Y, FORCE_Y). Are these values non-dimensional? Since there is no unit displayed in first row (title row) in history.csv file produced. If I want to see dimensional values of forces and moment, how can I see it? Currently I have length_ref=0.1 and area_ref=0.