Journal ArticleDOI
Helicopter trim with flap-lag-torsion and stall by an optimized controller
TLDR
In this article, an autopilot is applied to helicopter rotor flap-lag-torsion equations to obtain the control settings for a trimmed flight condition, and the rotor aerodynamic description includes a stage-space dynamic stall model for lift and for pitching moments.Abstract:
An autopilot is applied to helicopter rotor flap-lag-torsion equations to obtain the control settings for a trimmed flight condition. The rotor aerodynamic description includes a stage-space dynamic stall model for lift and for pitching moments. Thus, the rotor is trimmed for flight conditions in which significant stall and torsional deformations are present. The autopilot is extended to Q-bladed rotors by a series of time-delay terms. As a result, the optimum gains and time constants depend upon the number of blades as well as upon the torsional stiffness.read more
Citations
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Aeroelastic Analysis of Helicopter Rotor Blades Incorporating Anisotropic Piezoelectric Twist Actuation
TL;DR: In this article, a simple aeroelastic analysis of a helicopter rotor blade incorporating embedded piezoelectric fiber composite, interdigitated electrode blade twist actuators is described.
Journal ArticleDOI
Forward flight trim and frequency response validation of a helicopter simulation model
TL;DR: In this paper, a new trim procedure that includes the calculation of the steady-state response of the rotor blades and is applicable to straight flight and steady coordinated turns is described, and the results of a validation study for a high-order linearized model of helicopter flight dynamics are presented.
Proceedings ArticleDOI
Vibration reduction in hingeless rotors using an actively controlled trailing edge flap: implementation and time domain simulation
An integrated airloads-inflow model for use in rotor aeroelasticity and control analysis
David A. Peters,A. Su +1 more
TL;DR: In this paper, a thin-airfoil-based model is presented for rotor aeroelasticity and control analysis, especially where eigenvalues are sought; the model is derived from thin airfoil theory and can be simplified to any degree desired; inflow is also expanded in shape functions which may be truncated to any desired texture.
References
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Journal ArticleDOI
Coupled flap-lag-torsional dynamics of hingeless rotor blades in forward flight
TL;DR: In this paper, the aeroelastic stability and response problem of the coupled flap-lag-torsional dynamics of an isolated hingeless rotor blade in forward flight is considered.
Journal ArticleDOI
Flap-Lag-Torsion Stability in Forward Flight
TL;DR: In this article, an aeroelastic stability of a three-degree flap-lag-torsion blade in forward flight is examined using an iterative procedure based on Floquet theory, and the periodic perturbation equations are solved for stability using Floquet transition matrix theory and constant coefficient approximation in the fixed reference frame.
An integrated airloads-inflow model for use in rotor aeroelasticity and control analysis
David A. Peters,A. Su +1 more
TL;DR: In this paper, a thin-airfoil-based model is presented for rotor aeroelasticity and control analysis, especially where eigenvalues are sought; the model is derived from thin airfoil theory and can be simplified to any degree desired; inflow is also expanded in shape functions which may be truncated to any desired texture.
Journal ArticleDOI
An integrated airloads-inflow model for use in rotor aeroelasticity and control analysis
David A. Peters,D. Barwey,A. Su +2 more
TL;DR: An integrated airloads-inflow model that is ideally suited for rotor aeroelasticity and control analysis, especially for cases in which eigenvalues are desired is offered.