Re: [Jsbsim-devel] Helicopter

[Simon J. M. <sim...@go...>]

Hi Ron,

I don't do a typical plane flight model so I'm ok with the alpha and beta
calcs.

I've not found any problems with auto rotation... The object it would seem
is to spin the prop up using the air rushing through it as the helicopter
loses hight and then at the last second change it's blade angle to brake
the descent.

The alpha beta on the blade isn't an issue .

Regards

Simon

On Sun, 25 Oct 2020, 23:35 Ron Jensen, <wi...@je...> wrote:

> I made FlightGear Robinson R-22 model using Thomas Kreitler's FGRotor. Not
> sure if its still available on-line or not. It was flyable with a complete
> set of helicopter controls. E.g. cyclic, collective and pedals.
>
> The biggest trick to implenting a helicopter is you must consider +/-180
> degrees on alpha and -/+ 90 degrees on beta. The typical airplane model
> won't
> cut it. Also, FGPropeller assumes an alpha and beta of 0, so you won't see
> anything like autorotation.
>
> Ron
>
> On Sunday 25 October 2020 03:58:34 pm Simon Julie Morley via Jsbsim-devel
> wrote:
> > Hi Sean,
> >
> > To be honest I wanted to try and see if I could make a helicopter using
> the
> > prop code, because I couldn't see why not.
> >
> > On Sun, 25 Oct 2020 at 21:12, Sean McLeod <se...@se...> wrote:
> > > Hi Simon
> > >
> > >
> > >
> > > I’m just getting started again in terms of looking at JSBSim based
> > > helicopter models.
> > >
> > >
> > >
> > > Thomas Kreitler improved the FGRotor model between 2010 – 2012.
> > >
> > >
> > >
> > >
> > >
> https://github.com/JSBSim-Team/jsbsim/blob/4840a621dafe1ce64970990ddaec3e
> > >86a1c7e082/src/models/propulsion/FGRotor.cpp
> > >
> > >
> > >
> > > He also added a fairly detailed helicopter model for the AH1S:
> > >
> > >
> > >
> > >
> > >
> https://github.com/JSBSim-Team/jsbsim/tree/4840a621dafe1ce64970990ddaec3e
> > >86a1c7e082/aircraft/ah1s
> > >
> > >
> > >
> > > In general there are very few JSBSim based helicopter models around
> when
> > > I last looked.
> > >
> > >
> > >
> > > Cheers
> > >
> > >
> > >
> > > *From:* Bill Galbraith <bil...@gm...>
> > > *Sent:* Sunday, October 25, 2020 8:08 PM
> > > *To:* 'Development issues' <jsb...@li...>
> > > *Subject:* Re: [Jsbsim-devel] Helicopter
> > >
> > >
> > >
> > > Simon,
> > >
> > >
> > >
> > > I had devoted some brain cells towards that idea a while ago, but never
> > > implemented it.
> > >
> > >
> > >
> > > Imagine a point mass, with a point vertical force located above it. At
> > > 50% collective, vertical force equals weight. Cyclic tilts that
> vertical
> > > force fore/aft, left/right. Displacing the cyclic yields a slight loss
> > > (sine of angle) loss of lift, requiring slightly more collective.
> > >
> > >
> > >
> > > The painful part comes when you try to fly it with a joystick. When you
> > > release the joystick, the cyclic returns back to neutral, the aircraft
> > > will slow to a hover. You basically need a joystick that has a trim
> > > lever, or allows you to reestablish the trim point.
> > >
> > >
> > >
> > > Enough to get your brain cells excited?
> > >
> > >
> > >
> > > Bill
> > >
> > >
> > >
> > > *From:* Simon Julie Morley via Jsbsim-devel [
> > > mailto:jsb...@li...
> > > <jsb...@li...>]
> > > *Sent:* Sunday, October 25, 2020 1:41 PM
> > > *To:* Development issues <Jsb...@li...>
> > > *Cc:* Simon Julie Morley <sim...@go...>
> > > *Subject:* [Jsbsim-devel] Helicopter
> > >
> > >
> > >
> > > Anyone here ever done one ?
> > >
> > >
> > >
> > > Want to talk about it, share knowledge ?
> > >
> > >
> > >
> > > Simon
> > >
> > >
> > >
> > >
> > >
> > >
> > > _______________________________________________
> > > Jsbsim-devel mailing list
> > > Jsb...@li...
> > > https://lists.sourceforge.net/lists/listinfo/jsbsim-devel
> > > _______________________________________________
> > > The JSBSim Flight Dynamics Model project
> > > http://www.JSBSim.org
> > > _______________________________________________
>
>
>
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