Helicopter stability and control modeling improvements and verification on two helicoptersA linearized model of helicopter flight dynamics is developed which includes the flapping, lead-lag, and dynamic inflow degrees of freedom (DOF). The model is a combination of analytical terms and numerically determined stability derivatives, and is used to investigate the importance of the rotor DOF to stability and control modeling. The results show that the rotor DOF can have a significant impact on some of the natural modes in a linear model. The flap and dynamic inflow DOF show the greatest influence. Flapping exhibits strong coupling to the body, dynamic inflow, and to lead-lag to a lesser extent. Dynamic inflow tends to damp the high-frequency flapping modes, and reduces the damping on coupled body-flap motion. Dynamic inflow also couples to the flapping motion to produce complex roots. With body-flap and lag regressing modes as exceptions, the results show essentially similar behavior for most modes of articulated and hingeless rotor helicopters.
Document ID
19900055419
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Schrage, D. P. (Georgia Inst. of Tech. Atlanta, GA, United States)
Peters, D. A. (Georgia Inst. of Tech. Atlanta, GA, United States)
Prasad, J. V. R. (Georgia Institute of Technology Atlanta, United States)
Stumpf, W. F. (Georgia Inst. of Tech. Atlanta, GA, United States)
He, Chengjian (Georgia Inst. of Tech. Atlanta, GA, United States)