FMA for Unsteady

[deenri...@gmail.com]

I've read a few threads, and am a bit confused. 

When running a steady analysis, the actuator disk forces are not added to the "Sweep" data. The user would have to add the propulsion forces manually. 

What about when running the unsteady analysis, the  average of the last full cycle forces of the  prop/lift  rotor forces are added to the Sweep aerodynamic forces? Does this include any propulsion induced moments about the CG? Or are they bookkept separate under the T/QS variable?

One last question, in the unsteady results, is the "Moment" variable the rotor torque?

Thanks for the help, 

Daniel

[Rob McDonald]

You should be able to construct some simple tests to verify these questions for yourself.

For example, if you run an isolated rotating blade in unsteady mode -- I think you will see that the blade's contributions are included in the total forces and moments.  

Yes, I believe the last full rotation is what is added in.  If you have multiple rotors at different speeds, I think it is the last full rotation of the slowest rotor that is the period for averaging.

Yes, the Moment in the Rotor file is the rotor torque.

Unsteady motion is broken into 'groups'.  Forces and moments are first summed by group and then totaled up.  Groups can be identified as rotors -- in that case, forces are summed to result in a thrust and moment as well as rotor coefficients.

When OpenVSP uses CT, CP, the coefficients are non-dimensionalized using propeller conventions.  When CT_H and CP_H, helicopter rotor conventions are used.

Rob

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