Aiaa 98-4175 a Model of Atmospheric Turbulence for Rotorcraft Simulation and Analysis of Stability and Performance
نویسنده
چکیده
The purpose of this paper is to present the development of a simple turbulence representation suitable for helicopter dynamic simulation, stability and performance analysis, as well as pilot-in-the-loop rotorcraft handling qualities assessment. The frozen field hypothesis and linear approximation are assumed. Components of the uniform field velocity are included as additive perturbations affecting aerodynamic terms of the state matrix. Effects of the spatial gradients on parts of the helicopter other than rotor are considered as equivalent rotations. Effects of the spatial gradients on the rotor are considered by means of equivalent blade pitch angle perturbations. Vertical gradients are neglected. Equivalent blade pitch angle perturbations are determined such that total aerodynamic forces and moments over the rotor disc are conserved. The approach leads to a linear system with part of the input random. Some simulation results are presented to illustrate behavior and use of the model.
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