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YASim: Difference between revisions
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Update for version 2018.1
m (→fuselage: them -> the) |
(Update for version 2018.1) |
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* <code>YASIM_VERSION_32</code> enable bugfixes up to version 3.2 | * <code>YASIM_VERSION_32</code> enable bugfixes up to version 3.2 | ||
* <code>2017.2</code> enable bugfixes up to version 2017.2 | * <code>2017.2</code> enable bugfixes up to version 2017.2 | ||
* <code>YASIM_VERSION_CURRENT</code> use latest version compiled into the users FlightGear. | * <code>2018.1</code> (FIXME) no bugfixes by now. Use this version if your aircraft makes use of new features in YASim 2018.1 so it will cause at least a warning with older FG versions. | ||
* <code>YASIM_VERSION_CURRENT</code> use latest version compiled into the users FlightGear. | |||
{{Warning| Using YASIM_VERSION_CURRENT might make the aircraft unusable in case of future changes to YASim without updating the aircraft accordingly.}} | |||
=== approach === | === approach === | ||
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* '''effectiveness:''' Multiplier for the "normal" drag generated by the wing. Defaults to 1. Arbitrary, dimensionless factor. | * '''effectiveness:''' Multiplier for the "normal" drag generated by the wing. Defaults to 1. Arbitrary, dimensionless factor. | ||
* '''camber:''' The lift produced by the wing at zero angle of attack, expressed as a fraction of the maximum lift produced at the stall AoA. | * '''camber:''' The lift produced by the wing at zero angle of attack, expressed as a fraction of the maximum lift produced at the stall AoA. | ||
'''New in 2018.1:''' | |||
Wing section support to define variable geometry (geometry parameters per section) | |||
* '''append="1"''' use this for additional '''wing''' elements to skip x, y, z, chord and incidence attribute as the will be calculated from previous '''wing''' element tip chord | |||
==== hstab ==== | ==== hstab ==== | ||
These defines the horizontal stabilizer of the aircraft. Internally, it is just a wing object and therefore works the same in XML. You are allowed only one hstab object; the solver needs to know which wing's incidence to play with to get the aircraft trimmed correctly. | These defines the horizontal stabilizer of the aircraft. Internally, it is just a wing object and therefore works the same in XML. | ||
You are allowed only one hstab object; the solver needs to know which wing's incidence to play with to get the aircraft trimmed correctly. | |||
'''New in 2018.1:''' '''hstab''' supports sections in the same way '''wing''' does, but it is still considered as /the/ (only) hstab used by the solver. | |||
==== vstab ==== | ==== vstab ==== | ||
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launchbar -> dashed line for up angles, T-line for down angles | launchbar -> dashed line for up angles, T-line for down angles | ||
A note about step (0) for Windows users: the mentioned path is inside the folder where Blender lives, something like <code>C:\Program Files\Blender Foundation\Blender\.blender\scripts</code>. | A note about step (0) for Windows users: the mentioned path is inside the folder where Blender lives, something like <code>C:\Program Files\Blender Foundation\Blender\.blender\scripts</code>. | ||
== Export of YASim internals to property tree == | |||
Ever wondered what is going on inside yasim? See the property tree under /fdm/yasim/ | |||
Some information is static and shows what yasim has compiled from your XML. | |||
Other information is "run-time" like forces, speed, acceleration, c.g. | |||
If note noted otherwise: | |||
* expect metric unit (meter, kilogram, newton, ...) | |||
* expect minimum version 2017.2 | |||
{| class="wikitable" | |||
|- | |||
! Path !! Description !! Information type !! min. version | |||
|- | |||
| accelerations/ || linear and rot. accelerations in aircraft coord. || run time || | |||
|- | |||
| debug/ || misc internals, for now subject to change without notice || run time || 2018.1 | |||
|- | |||
| forces/ || aerodynamic forces in N || run time || | |||
|- | |||
| velocities/ || linear and rot. velocities in aircraft coord. || run time || | |||
|- | |||
| model/cg-x-range-aft || desired CG range || compile time || | |||
|- | |||
| model/cg-x-range-front || desired CG range || compile time || | |||
|- | |||
| model/cg-x-max || CG hard limit from gear position || compile time || | |||
|- | |||
| model/cg-x-min || CG hard limit from gear position || compile time || | |||
|- | |||
| model/masses || shows the calculated mass points || compile time || | |||
|- | |||
| model/wings || wing parameters || compile time || | |||
|} | |||
== Command Line == | == Command Line == | ||
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== New features and bugfixes in version 2017.2 == | == New features and bugfixes in version 2017.2 == | ||
=== XML parser === | === XML parser === | ||
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* cg-min: default 25% (just a guess, better numbers are welcome) | * cg-min: default 25% (just a guess, better numbers are welcome) | ||
* cg-max: default 30% (just a guess, better numbers are welcome) | * cg-max: default 30% (just a guess, better numbers are welcome) | ||
{{Note| By convention 0% is leading edge, 100% is trailing edge, however the absolute values on x-axis are the other way round, e.g. nose is +x, tail is -x }} | {{Note| By convention 0% is leading edge, 100% is trailing edge, however the absolute values on x-axis are the other way round, e.g. nose is +x, tail is -x }} | ||
{{warning|The MAC calculation | {{warning|The MAC calculation in version 2017.2 works only on the <wing> element. Numbers will be wrong, if your model uses a combination of <wing> and <mstab> to build a wing with two or more sections. | ||
Section support will be added in version 2018.1}} | |||
YASim will print the leading edge coordinates of the MAC (x,y) and its length. | YASim will print the leading edge coordinates of the MAC (x,y) and its length. | ||
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(*1) MAC calculation works on <wing> only! Numbers will be wrong for segmented wings, e.g. <wing>+<mstab>. | (*1) MAC calculation works on <wing> only! Numbers will be wrong for segmented wings, e.g. <wing>+<mstab>. | ||
</pre> | </pre> | ||
=== Aircraft developer helpers === | === Aircraft developer helpers === | ||
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* Ground effect: corrected the calculation of the height where g.e. ends | * Ground effect: corrected the calculation of the height where g.e. ends | ||
* Stall parameters were set wrong for wings with camber=0 | * Stall parameters were set wrong for wings with camber=0 | ||
== New features and bugfixes in version 2018.1 == | |||
The following is under development and hopefully finds its way into FG version 2018.1 | |||
=== Wing Section Support === | |||
Many airliners have wings with a geometry that is just a little more complex than what YASim supported initially (tapered wing with some angles like sweep, dihedral, ...), e.g. they have an inboard section and an outboard section that can be described with YASim wing syntax. You can use a wing + a mstab XML element to describe this geometry but it is easier if YASim can just append more wing sections by simply adding more wing XML elements. This is now (Version 2018.1) possible, yasim will simply append sections if it finds more than one wing or hstab in the XML. | |||
You should use <wing append="1" ... > for all but the first wing/hstab declaration. | |||
{{Info|YASim will ignore the root point (x,y,z), the chord length and the incidence attributes, if you add append="1" and calculate those from the previous wing section. }} | |||
MAC calculation works for the whole wing. | |||
== Related content == | == Related content == | ||