• Title/Summary/Keyword: Articulated Hub

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An Experimental Study on Flapping Motion of Forward Flight Condition used to Articulated Hub Rotor (관절형 허브 로터를 이용한 전진비행조건에서의 플래핑 운동에 대한 실험적 연구)

  • Ryi, Jae-Ha;Back, Dong-Min;Rhee, Wook;Choi, Jong-Soo;Song, Keun Woong
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.41 no.4
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    • pp.261-267
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    • 2013
  • In this paper, wind tunnel test and analytical prediction are compared for result of flapping motion in helicopter forward flight condition. Tests were performed at low speed wind tunnel at Chungnam National University, test section of wind tunnel has 1.8 by 1.8 meter open-jet test section area. According to the results of measured data for aerodynamic performance of model rotor in forward flight. It has to observed the difference of analytical and measured results of power coefficient for fixed thrust coefficient. And calculated and measured data of helicopter rotor flapping angles in forward flight are compared for a model rotor in a wind tunnel. A test was conducted to verify the measured data of coning and lateral/longitudinal flapping angle with predicted values.

Design and Simulation of Integral Twist Control for Helicopter Vibration Reduction

  • Shin, Sang-Joon;Cesnik Carlos E. S.;Hall Steven R.
    • International Journal of Control, Automation, and Systems
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    • v.5 no.1
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    • pp.24-34
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    • 2007
  • Closed-loop active twist control of integral helicopter rotor blades is investigated in this paper for reducing hub vibration induced in forward flight. A four-bladed fully articulated integral twist-actuated rotor system has been designed and tested successfully in wind tunnel in open-loop actuation. The integral twist deformation of the blades is generated using active fiber composite actuators embedded in the composite blade construction. An analytical framework is developed to examine integrally twisted helicopter blades and their aeroelastic behavior during different flight conditions. This aeroelastic model stems from a three-dimensional electroelastic beam formulation with geometrical-exactness, and is coupled with finite-state dynamic inflow aerodynamics. A system identification methodology that assumes a linear periodic system is adopted to estimate the harmonic transfer function of the rotor system. A vibration minimizing controller is designed based on this result, which implements a classical disturbance rejection algorithm with some modifications. Using the established analytical framework, the closed-loop controller is numerically simulated and the hub vibratory load reduction capability is demonstrated.

Bearingless Rotor Hub Composite Component Fatigue Analysis of Utility Helicopter to perform the Basic Mission (기본임무를 수행하는 기동헬기에 적용될 무베어링 허브 복합재 구성품 피로수명 해석)

  • Kim, Taejoo;Kee, Youngjoong;Kim, Deog-kwan;Kim, Seung-ho
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2013.04a
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    • pp.383-389
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    • 2013
  • Rotor system is a very important part which produces lift, thrust and control force in helicopter. Component of rotor system must endure various flight load for the required life. In helicopter rotor system, bearingless rotor system is the highest technology rotor system compare with articulated and hingeless rotor system. Baaringless rotor system is not include mechanical flap hinge, lag hinge and pitch bearing. Bearingless rotor component flexbeam which made by composite material has conduct hinge and bearing role instead of mechanical flap hinge, lag hinge and pitch bearing. These characteristics has less part number and lass weight than others. In this paper, conduct safe life analysis of bearingless composite component flexbeam and torque tube applying to utility helicopter load condition.

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