Generalized Quantitative Stability Analysis of Time-Dependent Comprehensive Rotorcraft Systems

Rotorcraft stability is an inherently multidisciplinary area, including aerodynamics of rotor and fuselage, structural dynamics flexible structures, actuator dynamics, control, augmentation systems. The related engineering models can be formulated with increasing complexity due to the asymmetric nature rotorcraft airflow on rotors in forward flight conditions. As a result, linear time-invariant (LTI) are drastic simplifications real problem, which significantly affect evaluation stability. This usually reveals itself form periodic governing equations solved using Floquet’s method. However, more general cases, resulting could non-periodic, as well, requires versatile approach. Lyapunov Characteristic Exponents (LCEs), quantitative method, represent solution this problem. LCEs generalize solutions models, i.e., eigenvalues LTI systems Floquet multipliers time-periodic (LTP) systems, case non-linear, time-dependent Motivated by need for generic tool analysis, work investigates use their sensitivity analysis time-dependent, comprehensive models. modeled mid-fidelity tools considered illustrate equivalence characteristic coefficients problems.