FAST FLOQUET THEORY AND TRIM FOR MULTI-BLADED ROTORCRAFT

Dynamic analysis of rotorcraft usually involves a nonlinear trim solution followed by a linearized Floquet analysis. This paper utilizes results by McNulty and by McVicar and Bradley to show that, when the rotor is composed of Q identical blades, both the Floquet analysis and the trim can be obtained in 1/Q of the normal computing times. This paper also generalizes the earlier work to show that these savings can be obtained for most Floquet algorithms, for either individual-blade or multi-blade descriptions, and for multi-rotor aircraft. Finally, the general result leads to a new formulation of multi-blade coordinates.