Simulation Investigation of Rotor Loads and Blade Deformations in Steady States and at Boundaries of Helicopter Flight Envelope

Open access

Abstract

Results of calculation of the helicopter main rotor loads and deformations of rotor blades are presented. The simulations concern level flight states and cases of boundary flight envelope such as wind gust, dive recovery and pull-up manoeuvre. The calculations were performed for data of the three-bladed articulated rotor of light helicopter. The method of analysis assumes modelling the rotor blades as elastic axes with sets of lumped masses of blade segments distributed along radius of blade. The model of deformable blade allows flap, lead-lag and pitch motion of blade including effects of out-of-plane bending, in-plane bending and torsion due to aerodynamic and inertial forces and moments acting on the blade. Equations of motion of rotor blades are solved applying Runge-Kutta method. Parameters of blade motion, according to Galerkin method, are considered as a combination of assumed torsion and bending eigen modes of the rotor blade. The rotor loads, in all considered cases of flight states, are calculated for quasi-steady conditions assuming the constant value of the following parameters: rotor rotational speed, position of the main rotor axis in air and position of swashplate due to rotor axis which defines the collective and cyclic control pitch angle of blades. The results of calculations of rotor loads and blade deflections are presented in form of time-runs and as distributions on rotor disk due to blade elements radial and azimuthal positions. The simulation investigation may help to collect data for prediction the fatigue strength of blade applying results for steady flight states and for definition the extreme loads for boundaries of helicopter flight envelope.

If the inline PDF is not rendering correctly, you can download the PDF file here.

  • [1] Johnson W. Milestone in Rotorcraft Aeromechanics NASA/TP-2011-215971 2011.

  • [2] Bousman W. G. Kufeld R. M. UH-60A Airloads Catalog NASA/TM-2005-212827 2005.

  • [3] Olson L. E. Abrego A. I. Barrows D. A. Burner A. W. Blade Deflections Measurements of a Full-Scale UH-60A Rotor System American Helicopter Society Aeromechanics Specialist Conference San Francisco California 2010.

  • [4] Abrego A. I. Meyn L. Burner A. W. Barrows D. A. Summary of Full-Scale Blade Displacement Measurements of the UH-60A Airloads Rotor American Helicopter Society Technical Meeting on Aeromechanics Design for Vertical Lift San Francisco California 2016.

  • [5] Yeo H. Johnson W. Comparison of Rotor Structural Loads Calculated Using Comprehensive Analysis 31st European Rotorcraft Forum Florence 2005.

  • [6] Biedron R. T. Lee-Rausch E. M. Computation of UH-60A Airloads Using CFD/CSD Coupling on Unstructured Meshes American Helicopter Society 67th Annual Forum Virginia Beach Virginia 2011.

  • [7] Gula P. Gorecki T. Design Experiments and Development of a Polish Unmanned Helicopter ILX-27 39st European Rotorcraft Forum Moscow 2013.

  • [8] Stanisławski J. Experimental measurements and simulation calculations of load in control system of helicopter Transactions of the Institute of Aviation No. 1 (238) pp. 35-53 2015.

Search
Journal information
Metrics
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 2 2 1
PDF Downloads 2 2 0