A Momentous Occasion

The pitching moment code is done (and the lift code is fixed; my integration code had a bug), and it seems to work! Watch:

> (require "../zfoil.rkt"            "../airfoils.rkt")

> (define my-geo (make-geometry naca-4412))

> (define alphas '(-0.05 0.0 0.05 0.1 0.15))

> (define CMs (for/list [(alpha alphas)]                 (CM alpha my-geo)))

> (plot (points (for/list [(alpha alphas)                            (CM CMs)]                   (vector alpha CM)))         #:x-label "alpha"         #:y-label "Cm"         #:y-max -0.1         #:y-min -0.14)

(object:2d-plot-snip% ...)

This agrees pretty well with other numerical methods, and more importantly, agrees with actual data available here.

Next, viscous flow and drag. This is to be strictly "cook book" for now. We’ll see if I am bored into motionless, or code it up quickly so I can actually play with my new toy!