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 and for either individual-blade or multi-blade descriptions. Finally, the general result leads to a new formulation of multi-blade coordinates.