This paper describes the numerical analysis of a stall suppression system for helicopter rotors. The analysis employs a finite element method and includes advanced dynamic stall and vortex wake models. The stall suppression system is based on a transfer function matrix approach and uses blade root actuation to suppress stall directly. The rotor model used in this investigation is the UH-60A rot...

This paper presents an off-line (finite time interval) and on-line learning direct adaptive neural controller for an unstable helicopter. The neural controller is designed to track pitch rate command signal generated using the reference model. A helicopter having a soft inplane four-bladed hingeless main rotor and a four-bladed tail rotor with conventional mechanical controls is used for the si...

Rotor blades of helicopters must be stiff and strong enough to maintain structural loads within working limits. The rotating cycles change the aerodynamic stresses created by blade revolution. In this project, you will discover as well vibration frequencies studied using Ansys programme, taking into consideration environmental consequences. This material was tested utilising Kevlar 49, carbon-e...

In this paper, we present a stabilization and trajectory tracking controller in discrete –time for an autonomous four rotor mini-rotorcraft. The control algorithm proposed is based on the feedback linearization input-output for nonlinear discrete-time systems. The dynamic model of the autonomous four rotor rotorcraft is obtained via Lagrange formalism. Simulation results are presented to illust...

Title of dissertation: COMPREHENSIVE AEROELASTIC ANALYSIS OF HELICOPTER ROTOR WITH TRAILING-EDGE FLAP FOR PRIMARY CONTROL AND VIBRATION CONTROL Jinwei Shen, Doctor of Philosophy, 2003 Dissertation directed by: Professor Inderjit Chopra Department of Aerospace Engineering A comprehensive aeroelastic analytical model of helicopter rotors with trailingedge flaps for primary and vibration controls ...

This paper presents results for a 31 variable helicopter rotor design example. Results are given for several numerical methods. This is a brief description of a portion of the Boe-ing/IBM/Rice University collaboration whose purpose is to develop eeective numerical methods for managing the use of approximation concepts or response surface methodology in design optimization.

A fluid-structure analysis framework which couples Computational Fluid Dynamics (CFD) and Computational Structural Dynamics (CSD) is constructed to study the aero-mechanics of a helicopter rotor system under maneuvering flight conditions. The CFD approach consists of the solution of Unsteady Reynolds Average Navier Stokes (URANS) equations for the near-field of the rotor coupled with the dynami...

As part of a research activity at Politecnico di Torino, aiming to develop multi-disciplinary design procedures implementing nature inspired meta-heuristic algorithms, a performance design optimization procedure for helicopter rotors has been developed and tested. The procedure optimizes the aerodynamic performance of blades by selecting the point of taper initiation, the root chord, the taper ...

Modern helicopter rotor blades constructed of composite materials offer significant inspection challenges, particularly at inner structures, where geometry and differing material properties and anisotropy make placement of the probing energy difficult. This paper presents an application of Lamb waves to these structures, where mode conversion occurs at internal geometric discontinuities. These ...

This paper describes a simulation model that has been used for controller design and stability and performance analysis of a micro X-CELL helicopter as central element of the Autonomous Scout Rotorcraft Testbed (ASRT) developed at Georgia Institute of Technology, Atlanta, USA. The general model, simple, yet comprehensive and efficient for the task at hand, consists of the following elements: he...