Board index FlightGear Development Aircraft

Dassault Mirage 2000 H08 (2007 Version) update

Questions and discussion about creating aircraft. Flight dynamics, 3d models, cockpits, systems, animation, textures.

Re: Dassault Mirage 2000 H08 (2007 Version) update

Postby wlbragg » Mon Jun 22, 2020 6:00 pm

Changed FDM from JBSIM to YASIM and changed approach speed

Hot button issue. Why did you opt to change the entire FDM for something like approach speed? Was it not possible to change it in JSBSim?
Is this a "private/personal" repository?
I noticed 2 Mirage 2000 in fgaddon, one YASim and one JSBSim. Is it either of those aircraft?
edit:
Spent a little time researching and my local fgaddon repo is outdated.
Kansas(2-27-15)/Ohio/Midwest scenery development.
KEQA (2-27-15), 3AU, KRCP Airport Layout
Intel i5 3570K AMDRX480
User avatar
wlbragg
 
Posts: 5539
Joined: Sat Aug 25, 2012 11:31 pm
Location: Kansas (Tornado Alley), USA
Callsign: WC2020
Version: next
OS: Win10/Linux/AMDRX480

Re: Dassault Mirage 2000 H08 (2007 Version) update

Postby openflight » Tue Jun 23, 2020 7:35 am

With the greatest respect, that is the dumbest thing I've read. YASIM is VERY unrealistic.


I know that now, but at that time I did not understand JBSIM and was more comfortable editing the YASIM configuration. It worked out OK visually, with a higher AoA possible at lower speeds, at least in my experience.
openflight
 
Posts: 454
Joined: Fri Sep 16, 2011 11:14 am
Version: 1 2 2018
OS: Linux Mint 19.3

Re: Dassault Mirage 2000 H08 (2007 Version) update

Postby openflight » Tue Jun 23, 2020 7:38 am

wlbragg wrote in Mon Jun 22, 2020 6:00 pm:
Changed FDM from JBSIM to YASIM and changed approach speed

Hot button issue. Why did you opt to change the entire FDM for something like approach speed? Was it not possible to change it in JSBSim?
Is this a "private/personal" repository?
I noticed 2 Mirage 2000 in fgaddon, one YASim and one JSBSim. Is it either of those aircraft?
edit:
Spent a little time researching and my local fgaddon repo is outdated.


That's the point, I did not know how to change it in JBSIM, and at that time I thought YASIM was 'just ok' and JBSIM was good if you had the actual flight data, which is what it says here:


YASim and JSBSim have different problems with regards to accurately emulating a real-life aircraft. Since YASim is solver-based, you do not need wind-tunnel data or accurate tables of propeller performance; you simply tell it some basic aircraft parameters and it will attempt to find a solution that approximates the aircraft's aerodynamics model. JSBSim uses detailed tables of performance and lift/drag numbers instead; JSBSim has no concept of wings or fuselage. Instead, drag, lift, and other forces are computed as functions of alpha (pitch), beta (yaw), control deflection, flap deflection, etc. This means that JSBSim needs accurate data to produce an accurate flight model.

Both YASim and JSBSim have their niche; YASim is simpler to get started with but it's not as easily matched to a real aircraft's performance, while JSBSim is much more difficult to use but is more controllable.


http://wiki.flightgear.org/JSBSim_vs_YASim
openflight
 
Posts: 454
Joined: Fri Sep 16, 2011 11:14 am
Version: 1 2 2018
OS: Linux Mint 19.3

Re: Dassault Mirage 2000 H08 (2007 Version) update

Postby Octal450 » Tue Jun 23, 2020 1:20 pm

YASim just uses geometric data to modify a generic flight model.
As I stated, I've flown a few airplanes, and I've never seen a single yasim that doesnt have at least one glaring problem that makes it completely unrealistic (usually in pitch or yaw) that is so bad it can make it unflyable.

In fact, I could take a generic Aeromatic and modify it to be more realistic in less time. Or just not waste time and make a custom FDM.

Kind Regards,
Josh
What I do: Flight Dynamics, Systems, Canvas Displays, Autoflight, FlyByWire, Cockpit Animations
Aircraft I currently develop: MD-11 (Mainly), A320-family, Secret (Quality over Quantity)

My GitHub|MD-11 and ITAF Dev Discord|Airbus Dev Discord
User avatar
Octal450
 
Posts: 4635
Joined: Tue Oct 06, 2015 12:51 pm
Callsign: WTF411/Octal
Version: next
OS: Windows 10 x64

Re: Dassault Mirage 2000 H08 (2007 Version) update

Postby openflight » Tue Jun 23, 2020 4:24 pm

So Aeromatic is the thing to try, however it did not work with my version, I recall there was an earlier version or a tweak.

Or I could tweak the existing....
openflight
 
Posts: 454
Joined: Fri Sep 16, 2011 11:14 am
Version: 1 2 2018
OS: Linux Mint 19.3

Previous

Return to Aircraft

Who is online

Users browsing this forum: YandexBot [Bot] and 1 guest