An Analytical Evaluation of the Controllable Twist Rotor Performance and Dynamic Behavior

摘要

A detailed analytical evaluation is made of a new rotor system with torsionally elastic blades and dual controls-the controllable twist rotor (CTR). The controls consist of conventional pitch horn linkages at the inboard end and an aerodynamic control flap at the outboard end. The analysis involves an aerolastic loads digital computer program which was developed to account for the blade response modes and blade control modes on either single or dual control rotors. Six response modes are included: blade flapping, blade feathering, blade lagging, blade flapwise bending, blade torsion, and control flap feathering. The two control modes are included separately and incorporate control system stiffness so that control loads are calculated. The aeroelastic analysis includes nonlinear inertia distributions, nonlinear airfoil characteristics, and inertial and mechanical coupling among the modes. The analysis outputs transient responses for stability evaluation and steady-state blade load and angle-of-attack distributions, blade dynamics, and rotor performance for each trimmed flight condition. (Author)