helicopter plus turbine generator

[mue]

what a dumb ase !

?

When I did the fixed wing plane I added procession last, as it was just an inconvenience to the pilot but not a big deal.... Having just watched the 'getting smarter everyday' youtube series on helicopters, seems procession is not something to be added at the end but is rather fundamental.

Simon

AFAIU gyroscopic precession is a negligible effect in rotor dynamics. There are other (maybe more prominent) effects, e.g. phase lag, blade flapping, blade coning, flapping-hinge offet, ... .
Do you try to develop your own rotor model?
Why not using the JSBSim rotor model? I think JSBSim's rotor model is based on this: https://ntrs.nasa.gov/search.jsp?R=19790005912. Maybe this model is good enough for your purposes?

[bomber]

Why not use a rotor ?

Fair question.. I guess because I wanted to understand all the spects of the rotor rather than having it prescribed to me and not fully understand what each bit did and how it was implemented... I'm not saying the rotor code is wrong. What I have learnt is that there's sometimes the need to compromise to say 'this effect or that effect is negliable'. Now if that's already been done within the rotor code, undoing it can be hard to impossible.

So I wanted to start with a simple aproach, take a prop and model its coefficients for thrust and power for a rotor. Calculate it's inertia using mass and size and link this rotor to a constant speed electric motor. With this aproach I can then adjust the pitch of the blades simulating the collective. Cyclic control is just a matter of moving the point of origin of the rotor thrust and it's direction.

For the Scorpion, there are 2 contra rotating rotors, I need to be able to adjust the blade pitch angle via a collective. Roll being adjusted by differing blade pitch between left and right. Pitch/forward & backwards being adjusted by rotating both rotors back and forth and yaw by one rotor going forward and one back.... and there's a lot of cross coupling going on.

There's a lot to get my head around.

Simon

[IAHM-COL]

There's a lot to get my head around.

Simon

And given the model shown in the video you've posted, there should be more still.
That model actually in addition to the two counterrotating rotors have:

1. Parallel wings at an angle of like 45. The lower wing has attached weaponry, the upper wing has the rotors. ie, where the rotors are mounted, for aerodynamic purposes that's a wing. and should generate lift given speed and AoA just like your regular glider. Just suckier/stallable.
2. Besides, this thing also has what appears to be ailerons on the upper (rotor mounting) wings. So directional control goes cyclic + aileron effects.
3. Besides, this thing appear to have a twin tail equiped with an horizontal stabilizer, well equipped with elevators, and a nice pair of rudders.

Call me an hybrid, and I'll flight like an helicopter, the designer of the scorpio said. IH-COL says, you've got no idea but that's gonna fly like mixing a CR42 Falco with a B-25 and a twin-prop drone..

[bomber]

Well that's where some of the compromise or possible negliable effects come into the equation

1) they're not really wings, would offer some lift but only a couple of lbs force at max speed
2) they're not ailerons they're vine cutters
3) I'm not sure they have control surfaces... but these could be modeled if they're needed.

[bomber]

2) ailerons ?

Took another look....

https://www.youtube.com/watch?v=ySh4xcg9jD4

0.22 secs on this video shows the rotor anular motor stators (mouthfull)... the grey sections could be considered aileron effective but seems counter to rotating the rotors for forward progression....

see here for tech spec

https://james-camerons-avatar.fandom.co ... on_Gunship

Always worth a re-read

"overall vehicle pitch is induced through cyclic pitch of the rotors, which is actuated by the same servos as the collective pitch"

So pushing the stick forward you not only get the rotor blades pitch cyclic behaviour but also the whole rotor rotates forward giving forward progression

Didn't see that... as I said well worth having a re-read

regards

Simon

[IAHM-COL]

Took another look....

https://www.youtube.com/watch?v=ySh4xcg9jD4

Needing to close my jaw now. Specially when the model flew.

[bomber]

Anyone know if the Osprey uses jsbsim. ?

[IAHM-COL]

The two versions I know of are Yasims,
ie;

[*] https://github.com/FGMEMBERS/V-22
--> https://github.com/FGMEMBERS/V-22/blob/master/mv22.xml

[*] https://github.com/FGMEMBERS/VMX22-Osprey
--> https://github.com/FGMEMBERS/VMX22-Ospr ... /vmx22.xml

[bomber]

Cheers.

It's an interesting looking vehicle, not too dissimilar to the fictitious Scorpion... I expect it's FCS will roughly be similar too.

[IAHM-COL]

the fictitious Scorpion...

Yes, indeed, they appear to be of the same family :p