The effects of unsteady aerodynamics on the stability characteristics of helicopter rotor blades were studied. A simple physical model of each blade was used together with Theodorsen, Loewy, and quasi-steady aerodynamics to derive the equations of motion. The stability analysis comparing the effects of using each of the three theories revealed some significant differences between the Loewy and Theodorsen results. These included increases and decreases in lead-lag damping, localized around integer lead-lag frequencies. It was also shown that the standard method of multi-blade coordinates must be modified for use in conjunction with Loewy aerodynamics.
Effects of Unsteady Aerodynamics on Rotor Aeroelastic Stability
1977
30 pages
Report
No indication
English