YASim: Difference between revisions

*'''cx,cy,cz:''' Factors for the generated drag in the fuselages "local coordinate system" with x pointing from end to front, z perpendicular to x with y=0 in the aircraft coordinate system. E.g. for a fuselage of a height of 2 times them width you can define cy=2 and (due to the doubled front surface) cx=2.

This defines the main wing of the aircraft.  You can have only one (but see below about using vstab objects for extra lifting surfaces). The wing should have a <stall> subelement to indicate stall behavior, control surface subelements (flap0, flap1, spoiler, slat) to indicate what and where the control surfaces are, and <control> subelements to map user input properties to the control surfaces.

*'''x,y,z:'''    The "base" of the wing, specified as the location of the mid-chord (not leading edge, trailing edge, or aerodynamic center) point at the root of the LEFT (!)  wing.

*'''idrag:'''    Multiplier for the "induced drag" generated by this surface.  In general, low aspect wings will  generate less induced drag per-AoA than high aspect (glider) wings.  This value isn't constrained well by the solution process, and may require tuning to get throttle settings correct in high AoA (approach) situations.

*'''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.

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.

A "vertical" stabilizer.  Like hstab, this is just another wing, with a few special properties.  The surface is not "mirrored" as are wing and hstab objects.  If you define a left wing only, you'll only get a left wing.  The default dihedral, if unspecified, is 90 degrees instead of zero. But all parameters are equally settable, so there's no requirement that this object be "vertical" at all.  You can use it for anything you like, such as extra wings for biplanes.  Most importantly, these surfaces are not involved with the solver computation, so you can have none, or as many as you like.

A mirrored horizontal stabilizer. Exactly the same as wing, but not involved with the solver computation, so you can have none, or as many as you like.

A subelement of a wing (or hstab/vstab/mstab) that specifies the stall behavior.

*'''aoa:'''  The stall angle (maximum lift) in degrees.  Note that this is relative to the wing, not the fuselage (since the wing may have a non-zero incidence angle).

*'''peak:'''  The height of the lift peak, relative to the post-stall secondary lift peak at 45 degrees. Defaults to 1.5.  This one is deep voodoo, and probably doesn't need to change much.  Bug me for an explanation if you're curious.

These are subelements of wing/hstab/vstab objects, and specify the location and effectiveness of the control surfaces.

*'''start:'''  The position along the wing where the control surface begins.Zero is the root, one is the tip.