Menu
▾
▴
Re: [Jsbsim-devel] Fwd: Helicopter
|
From: Simon J. M. <sim...@go...> - 2020-10-27 09:40:52
|
Ok to answer the question about the tail rotor. It's a force that produces a moment equal and opposite to the main rotor n_moment. The collective increases or reduces this force value by up to 10% On Tue, 27 Oct 2020, 00:56 Thomas, <kre...@mo...> wrote: > Hi Simon, > > sorry now for quoting into your response. > > Simon Julie Morley wrote: > > No offense intended, it's not like I'm critising jsbsim as I'm using it. > > IMHO, youre welcome > > > > > I chose to attempt to model a helicopter by adapting the propeller > > code.... I shouldn't be critised for doing this. > > Well, call/interpretate the critism just as 'questions' about your > intention, or simply as advice (you are trying something new, or?), > since I guess the people in this forum all have their individual > 'zugang' to jsbsim. > > > > > This is my hobby, if you feel me doing something is a personal insult > > and that we shouldn't talk about it, and that I shouldn't answer > > questions raised to me then I'm at a loss as to the point of this forum.. > > No, again, feel free to exercise jsbsim -- but what's wrong about > explaining what you like to do? My answer was a respose to your > statement. Should I accept it, or should I pose a question? > Alternatively, this could be a starting point for a discussion... > > Thomas > > > > > > Simon > > > > On Mon, 26 Oct 2020, 22:47 Thomas, <kre...@mo... > > <mailto:kre...@mo...>> wrote: > > > > Hello Simon, > > > > I'm a bit offended by your claim -- CIT: 'there's nothing in it I > can't > > do with a propeller'. > > > > Allow me one question: how do you intend to treat the tail-rotor? > > > > Anyway, I'm curious about your results. 'think that the propeller is > > better suited to model mid-size quad-drones and the like. > > > > Kind Regards, > > > > Thomas > > > > P.S. As for the rotor-model, two pointers for reading: > > > > /br/ > > > https://www.elsevier.com/books/bramwells-helicopter-dynamics/bramwell/978-0-08-097404-0 > > > > /sh/ Shaugnessy, J. D., Deaux, Thomas N., and Yenni, Kenneth R., > > "Development and Validation of a Piloted Simulation of a Helicopter > and > > External Sling Load", NASA TP-1285, 1979 > > > > > > Simon Julie Morley via Jsbsim-devel wrote: > > > > > > yeh I have, and there's nothing in it I can't do with a > propeller, > > > and actually there are things in the propeller code that the > > rotor can't > > > do.... so using rotor is a net less... > > > > > > Simon > > > > > > ---------- Forwarded message --------- > > > From: *Sean McLeod* <se...@se... > > <mailto:se...@se...> <mailto:se...@se... > > <mailto:se...@se...>>> > > > Date: Mon, 26 Oct 2020 at 20:00 > > > Subject: RE: [Jsbsim-devel] Helicopter > > > To: Simon Julie Morley <sim...@go... > > <mailto:sim...@go...> > > > <mailto:sim...@go... > > <mailto:sim...@go...>>> > > > > > > > > > Hi Simon____ > > > > > > __ __ > > > > > > Have you looked at the FGRotor code to see what helicopter > specific > > > stuff it models that isn’t modeled by FGPropeller?____ > > > > > > __ __ > > > > > > Cheers____ > > > > > > __ __ > > > > > > *From:* Simon Julie Morley <sim...@go... > > <mailto:sim...@go...> > > > <mailto:sim...@go... > > <mailto:sim...@go...>>> > > > *Sent:* Monday, October 26, 2020 5:19 PM > > > *To:* Sean McLeod <se...@se... > > <mailto:se...@se...> <mailto:se...@se... > > <mailto:se...@se...>>> > > > *Subject:* Re: [Jsbsim-devel] Helicopter____ > > > > > > __ __ > > > > > > Hi Sean,____ > > > > > > __ __ > > > > > > I'm not sure about using prop resulting in a lesser quality or > that > > > rotor offering greater functionality...____ > > > > > > __ __ > > > > > > I remain open minded to the possibilities____ > > > > > > __ __ > > > > > > Simon.____ > > > > > > __ __ > > > > > > On Mon, 26 Oct 2020, 13:08 Sean McLeod, <se...@se... > > <mailto:se...@se...> > > > <mailto:se...@se... <mailto:se...@se...>>> > wrote:____ > > > > > > Hi Simon____ > > > > > > ____ > > > > > > I’m sure you can model a helicopter using FGPropeller etc. as > a > > > basis, but I would imagine it would be a 1^st order > approximation > > > since there are a number of dynamics that FGPropeller doesn’t > > model > > > compared to FGRotor, so FGRotor would more easily allow for a > > higher > > > fidelity model.____ > > > > > > ____ > > > > > > Cheers____ > > > > > > ____ > > > > > > *From:* Simon Julie Morley via Jsbsim-devel > > > <jsb...@li... > > <mailto:jsb...@li...> > > > <mailto:jsb...@li... > > <mailto:jsb...@li...>>> > > > *Sent:* Sunday, October 25, 2020 11:59 PM > > > *To:* Development issues <jsb...@li... > > <mailto:jsb...@li...> > > > <mailto:jsb...@li... > > <mailto:jsb...@li...>>> > > > *Cc:* Simon Julie Morley <sim...@go... > > <mailto:sim...@go...> > > > <mailto:sim...@go... > > <mailto:sim...@go...>>> > > > *Subject:* Re: [Jsbsim-devel] Helicopter____ > > > > > > ____ > > > > > > 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... <mailto:se...@se...> > > > <mailto:se...@se... <mailto: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/4840a621dafe1ce64970990ddaec3e86a1c7e082/src/models/propulsion/FGRotor.cpp____ > > > > > > ____ > > > > > > He also added a fairly detailed helicopter model for the > > AH1S:____ > > > > > > ____ > > > > > > > > > https://github.com/JSBSim-Team/jsbsim/tree/4840a621dafe1ce64970990ddaec3e86a1c7e082/aircraft/ah1s____ > > > > > > ____ > > > > > > In general there are very few JSBSim based helicopter > models > > > around when I last looked.____ > > > > > > ____ > > > > > > Cheers____ > > > > > > ____ > > > > > > *From:* Bill Galbraith <bil...@gm... > > <mailto:bil...@gm...> > > > <mailto:bil...@gm... > > <mailto:bil...@gm...>>> > > > *Sent:* Sunday, October 25, 2020 8:08 PM > > > *To:* 'Development issues' > > <jsb...@li... > > <mailto:jsb...@li...> > > > <mailto:jsb...@li... > > <mailto: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... > > <mailto:jsb...@li...>] > > > *Sent:* Sunday, October 25, 2020 1:41 PM > > > *To:* Development issues > > <Jsb...@li... > > <mailto:Jsb...@li...> > > > <mailto:Jsb...@li... > > <mailto:Jsb...@li...>>> > > > *Cc:* Simon Julie Morley <sim...@go... > > <mailto:sim...@go...> > > > <mailto:sim...@go... > > <mailto: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... > > <mailto:Jsb...@li...> > > > <mailto:Jsb...@li... > > <mailto:Jsb...@li...>> > > > https://lists.sourceforge.net/lists/listinfo/jsbsim-devel > > > _______________________________________________ > > > The JSBSim Flight Dynamics Model project > > > http://www.JSBSim.org > > > ___________________________________________________ > > > > > > > > > > > > > > > > > > _______________________________________________ > > > Jsbsim-devel mailing list > > > Jsb...@li... > > <mailto:Jsb...@li...> > > > https://lists.sourceforge.net/lists/listinfo/jsbsim-devel > > > _______________________________________________ > > > The JSBSim Flight Dynamics Model project > > > http://www.JSBSim.org > > > _______________________________________________ > > > > > > > -- > > Thomas Kreitler - Information Retrieval > > kre...@mo... <mailto:kre...@mo...> > > 49/30/8413 1702 > > > > -- > Thomas Kreitler - Information Retrieval > kre...@mo... > 49/30/8413 1702 > |
