//'''a wind generation object//'''
public Wind (string windstring, double cross_section=0.1) {
self = this;
string[] a = windstring.Split(',');
if (Utils.len(a) != 3)
{
return;
//raise RuntimeError("Expected wind in speed,direction,turbulance form, not %s" % windstring);
}
self.speed = float.Parse(a[0]); //# m/s
self.direction = float.Parse(a[1]); //# direction the wind is going in
self.turbulance= float.Parse(a[2]); //# turbulance factor (standard deviation)
//# the cross-section of the aircraft to wind. This is multiplied by the
//# difference in the wind and the velocity of the aircraft to give the acceleration
self.cross_section = cross_section;
//# the time constant for the turbulance - the average period of the
//# changes over time
self.turbulance_time_constant = 5.0;
//# wind time record
self.tlast = DateTime.Now;
//# initial turbulance multiplier
self.turbulance_mul = 1.0;
}
//# See http://en.wikipedia.org/wiki/Drag_equation
//#
//# Drag equation is F(a) = cl * p/2 * v^2 * a, where cl : drag coefficient
//# (let's assume it's low, .e.g., 0.2), p : density of air (assume about 1
//# kg/m^3, the density just over 1500m elevation), v : relative speed of wind
//# (to the body), a : area acted on (this is captured by the cross_section
//# paramter).
//#
//# So then we have
//# F(a) = 0.2 * 1/2 * v^2 * cross_section = 0.1 * v^2 * cross_section
public double drag_force(Wind wind, double sp)
{
return (Math.Pow(sp,2.0)) * 0.1 * wind.cross_section;
}
//# See http://en.wikipedia.org/wiki/Drag_equation
//#
//# Drag equation is F(a) = cl * p/2 * v^2 * a, where cl : drag coefficient
//# (let's assume it's low, .e.g., 0.2), p : density of air (assume about 1
//# kg/m^3, the density just over 1500m elevation), v : relative speed of wind
//# (to the body), a : area acted on (this is captured by the cross_section
//# paramter).
//#
//# So then we have
//# F(a) = 0.2 * 1/2 * v^2 * cross_section = 0.1 * v^2 * cross_section
public double drag_force(Wind wind, double sp)
{
return((Math.Pow(sp, 2.0)) * 0.1 * wind.cross_section);
}