The design of new helicopters, as well as the prediction of the changes in the dynamic behavior as a consequence of structural modification will benefit of the availability of numerical tools capable to predict the vibration level characterizing the structure due to main rotor-fuselage interaction. These tools are of great importance to gather information concerning the fatigue-life of the structure, that in turn would allow a rough estimate of consequent maintenance costs. Furthermore, they would help in the process of identifying design solutions aimed to the reduction of interior noise, that is a crucial aspect for the widely-requested passenger comfort enhancement. In this paper, the capabilities of the ROTAERO simulation tool, developed at the Department of Mechanical and Aerospace Engineering of the University of Rome ``La Sapienza,'' to predict both the trim conditions and the vibration levels, characterizing a flying helicopter, are explored. A general modular solution algorithm is developed for the trim analysis of helicopters, in order to evaluate the stationary solution of equilibrium equations for rotorcraft, and for the vibratory loads. These last characteristics are evaluated with the aid of a finite element model of the fuselage forced by vibratory hub loads, that are predicted through the aeroelastic analysis of the main rotor treated as isolated. The developed numerical procedure seeks the solution following an iterative solution scheme that includes the modeling of the different subsystem such as the main and the tail rotor, the fuselage, and the aerodynamic surfaces. A Bo-105 helicopter is used as a numerical benchmark, whereas a Bergen Industrial Twin Unmanned Aerial Vehicle helicopter was used as a flying laboratory for the evaluation of the fuselage vibrations. A comparison between the numerical simulations, and the experimental findings, corresponding to flight tests with different advancing ratios, are reported for an overall assessment of the ROTAERO code.
A ROTORCRAFT TRIM PROCEDURE FOR THE PREDICTION OF FUSELAGE VIBRATIONS / Coppotelli, Giuliano; Cellini, F.. - ELETTRONICO. - 4(2012), pp. 235-257.
A ROTORCRAFT TRIM PROCEDURE FOR THE PREDICTION OF FUSELAGE VIBRATIONS
COPPOTELLI, Giuliano;
2012
Abstract
The design of new helicopters, as well as the prediction of the changes in the dynamic behavior as a consequence of structural modification will benefit of the availability of numerical tools capable to predict the vibration level characterizing the structure due to main rotor-fuselage interaction. These tools are of great importance to gather information concerning the fatigue-life of the structure, that in turn would allow a rough estimate of consequent maintenance costs. Furthermore, they would help in the process of identifying design solutions aimed to the reduction of interior noise, that is a crucial aspect for the widely-requested passenger comfort enhancement. In this paper, the capabilities of the ROTAERO simulation tool, developed at the Department of Mechanical and Aerospace Engineering of the University of Rome ``La Sapienza,'' to predict both the trim conditions and the vibration levels, characterizing a flying helicopter, are explored. A general modular solution algorithm is developed for the trim analysis of helicopters, in order to evaluate the stationary solution of equilibrium equations for rotorcraft, and for the vibratory loads. These last characteristics are evaluated with the aid of a finite element model of the fuselage forced by vibratory hub loads, that are predicted through the aeroelastic analysis of the main rotor treated as isolated. The developed numerical procedure seeks the solution following an iterative solution scheme that includes the modeling of the different subsystem such as the main and the tail rotor, the fuselage, and the aerodynamic surfaces. A Bo-105 helicopter is used as a numerical benchmark, whereas a Bergen Industrial Twin Unmanned Aerial Vehicle helicopter was used as a flying laboratory for the evaluation of the fuselage vibrations. A comparison between the numerical simulations, and the experimental findings, corresponding to flight tests with different advancing ratios, are reported for an overall assessment of the ROTAERO code.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
