Parameters for Skydiver, T-10 Canopy, Physics, ...

This section contains values for all parameters in the model.

> param0 :=

> g=9.81, # gravitational constant (kg m/s^2)

> rho = 1, # density of air (kg/m^3)

> mu=1.5*10^(-5), # viscosity of air (kg/m/s

> h=70 * 0.0254, # height of skydiver (m)

> mb=190/2.2, # mass of skydiver (kg)

> b0=0.5, # spread-eagle cross-sectional area (m^2)

> b1=0.1, # feet-first cross-sectional area (m^2)

> d0=35 * 0.3048, # nominal diameter of canopy (m)

> mh=10/2.2, # mass of harness (m)

> mc=13.85/2.2, # mass of canopy and suspension lines (m)

> beta1=0.15, # amount of overinflation (%)

> p=1, # exponent of line extension interpolant

> t0=10, # time ripcord is pulled (s)

> Dt1=0.5, # time for lines to extend (s)

> Dt2=1.0, # time for initial fill of canopy (s)

> Dt3=1.7, # time for remainder of deployment (s)

> x0=4000 * 0.3048, # initial height (m)

> NULL ;

>

> param1 := op(subs( param0, [

> l = 0.84*d0, # length of suspension lines

> dp = 0.7*d0, # projected nominal diameter

> m = mb+mh+mc, # total mass of person and equipment

> t1 = t0+Dt1, # time when snatch force felt

> t2 = t0+Dt1+Dt2, # time when opening force felt

> t3 = t0+Dt1+Dt2+Dt3, # time when deployment is complete

> NULL ] ));

>

> param2 := op(subs( param0, param1, [

> a1 = Pi*(dp/2)^2, # projected nominal area

> alpha0 = (1.95*b0+0.35*b1*(l-h))/1.33, # initial value for Ae12

> NULL ] ));

>

> param3 := op(subs( param0, param1, param2, [

> beta0 = log(a1/alpha0), # `growth rate' in Ae12

> NULL ] ));

> param4 := op(subs( param0, param1, param2, param3, [

> Ae12 = alpha0*exp(beta0*(t-t1)/(t2-t1)), # canopy area for [t1,t2]

> Ae23 = a1 * (1+beta1*sin(Pi*(t-t2)/(t3-t2))), # canopy area for [t2,t3]

> NULL ] ));

>

> param := { seq( param.i, i=0..4 ) };

>

> paramFF := select( has, param, {m,g} ) union {

> VtermFF=-44.7, # terminal free-fall velocity: 100 m/hr

> VtermD =-4.88, # rate of descent for T-10: 16 ft/sec

> x0=1.52, # landing impact comparable to jump from 5 ft (1.52m) wall

> NULL };

>