pub fn flare_corner_limit_rad(surface_mach: f64) -> Result<f64, AeroError>Expand description
The steepest turn the method reads at a flare’s corner, rad, where the surface flow reaching
that corner is surface_mach (ShockExpansionBody::aft_flow): the largest deflection
behind an attached plane oblique shock.
This is a bound on the turn, measured from the surface just ahead of the corner. The cone
tables’ crate::blunt_tip::CONE_TABLE_CAP_RAD bounds the flare’s surface angle instead,
since that is what an element’s tangent cone is looked up by, and a caller that draws a flare
to this turn must cap the angle it draws separately.
The attachment test. A flare’s shock springs from a circular corner, not from a point, so
where it forms the flow is two-dimensional: the body’s radius is the scale over which the
axisymmetric relief acts, and at the corner itself there is none of it yet. The test is
therefore NACA Report 1135’s largest deflection behind an attached plane oblique shock
(crate::blunt_tip::wedge_detachment_angle_rad, eq. 168 into eq. 138), read at the flow
reaching the corner rather than at the free stream. TN D-4865 p. 5 uses the same test to hand
a blunt tip’s cap over to this method (crate::blunt_tip::handover_angle_rad). A cone’s
shock holds to steeper angles than a wedge’s and a conical flare on a cylinder sits between
the two (ADR-045), so this is the conservative
side of the boundary: it stops reading some flares whose shock is in fact still attached, and
never marches one whose shock is not.
Where it is read matters. The march is downstream-only, so surface_mach is the flow the
body ahead delivers to the corner, not the free stream: on a flare behind an ogive nose and a
tube it comes out a little below the free stream, on one behind a cone and a tube a little
above (ADR-047).
§Errors
As crate::blunt_tip::wedge_detachment_angle_rad for the Mach number.