Module body 

Bodies of revolution (nose cones, body tubes, transitions): Barrowman’s normal-force slope and center of pressure, and the planform body lift acts on.

• Potential flow (slender-body theory). A body whose cross-section area runs from A(0) at its fore end to A(l) at its aft end has (C_Nα)_B = (2/A_ref)[A(l) − A(0)] (Barrowman 1966 eq. 10, 1967 eq. 3-65; Niskanen 2009 eq. 3.19) and its center of pressure X_B = [l A(l) − V] / [A(l) − A(0)] aft of its fore end, with V its volume (Barrowman 1966 eq. 28, 1967 eq. 3-89; Niskanen eq. 3.28). The moment slope (2/A_ref)[l A(l) − V] (Niskanen eq. 3.25 times d) stays well conditioned when A(l) ≈ A(0). At an angle of attack α, Niskanen keeps the sin α / α factor of the crossflow v₀ sin α (eq. 3.19). No Mach term: Barrowman 1967 p. 18 leaves body compressibility out, and Niskanen p. 22 takes the body’s normal force as the same at all speeds.
• Body lift: C_N = f (A_plan/A_ref) sin² α, acting at the centroid of the side-view (planform) area (Niskanen eq. 3.26–3.27). Its factor f is crate::crossflow’s: Jorgensen’s η C_dn since body lift was sized (M1.8e6), Galejs’s K = 1.1 before (after Hoerner p. 3-11). It is zero at α = 0, so it doesn’t change C_Nα there.

See docs/physics/aero.md.

Structs

BodyGeometry

The aerodynamic geometry of one body component, in its own frame (fore end at 0, stations positive aft).

Constants

BODY_LIFT_K

Galejs’s body-lift constant K (Niskanen 2009 eq. 3.26: “K ≈ 1.1”; Galejs quotes Hoerner’s 1.1 to 1.5 and fitted 1.0 to his own data): hpr’s body lift before Jorgensen’s, kept as crate::crossflow::BodyLift::GALEJS.