Thrust Calculation

Orb · February 24, 2013, 12:47

Hi,

I have a rotating machinery with one inlet and one outlet. If I want to find the total thrust force do I just use the Force(Z)-out function? Or do I subtract Force(Z)-out from Force(Z)-in? Which is more a more reasonable result?

Thank you

evcelica · March 1, 2013, 22:11

Should be the net of your control volume shouldn't it? So out minus in?

Orb · March 1, 2013, 22:42

Great suggestion. Although, I am unsure how ANSYS CFX calculates the force... maybe it already factors in the Force of air in, or maybe not.

Orb · March 3, 2013, 00:02

Doesn't it actually make sense to add them both? Force of fluid (air) through the inlet should be added to force of fluid (air) leaving the outlet... Both forces in the same direction...

February 24, 2013, 12:47	Thrust Calculation	#1
Orb Member Join Date: Jan 2012 Posts: 52 Rep Power: 14	Hi, I have a rotating machinery with one inlet and one outlet. If I want to find the total thrust force do I just use the Force(Z)-out function? Or do I subtract Force(Z)-out from Force(Z)-in? Which is more a more reasonable result? Thank you

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March 1, 2013, 22:11		#2
evcelica Senior Member Erik Join Date: Feb 2011 Location: Earth (Land portion) Posts: 1,188 Rep Power: 23	Should be the net of your control volume shouldn't it? So out minus in?

March 1, 2013, 22:42		#3
Orb Member Join Date: Jan 2012 Posts: 52 Rep Power: 14	Great suggestion. Although, I am unsure how ANSYS CFX calculates the force... maybe it already factors in the Force of air in, or maybe not.

March 3, 2013, 00:02		#4
Orb Member Join Date: Jan 2012 Posts: 52 Rep Power: 14	Doesn't it actually make sense to add them both? Force of fluid (air) through the inlet should be added to force of fluid (air) leaving the outlet... Both forces in the same direction...