General Aerodynamics
Posted: Tue Jun 12, 2007 11:48 pm
Why is induced flow generally considered "bad" for fully articulated rotor systems in-ground-effect (IGE) as opposed to out-of-ground effect (OGE)?
Well, I'm no engineer, but I believe that with fully articulated rotor (3 blade) helicopters, a big risk is ground resonance. IGE being at a lower altitude, the angle of attack is reduced and the reduced induced flow carries the hazard of the helicopter touching the ground, and the vibrations caused can produce ground resonance.
How ya been, brotha?