Winch launching

[Gliderguy]

Just curious if anyone has a formula for winch launch angle of attack. I realize there are practical conciderations like strength of the wing, power of the winch, line drag, and length of line etc., is there an ideal launch angle that would give max height at max speed? I understand also that there are several launch transitions and those need to be taylored to the plane. Just wondering about the physics of an ideal launch.


Gliderguy

[Ollie]

Soar Tech 10 (available from Carstens Publications) has an article by V. and L. De Filippis which is a thorough technical analysis of the physics of winch launching. Included are the definitions of the many variables, the derived formulas and the source code for a computer program that will allow exploration of the many trade offs involved in searching for the ideal launch.

Among other things, the analysis takes into account line speed, line drag, wind speed, winch characteristics, centrifugal force, the lift-drag polar of the glider, weight of the glider, acceleration of the glider, airspeed as the model leaves the hand, zoom after release, etc.

[Gliderguy]

Thanks Ollie. I'll have to get a copy of that.