Coupled pitch links for multiharmonic isolation using fluidic circuits

Research output: Contribution to journalArticle

Abstract

Replacing stiff pitch links on rotorcraft with coupled fluidic devices has the potential to reduce the aerodynamic blade loads transmitted through the pitch links to the swashplate. Analytical models of two fluidic devices coupled with three different fluidic circuits are derived. These passive fluidlastic systems are tuned, by varying the fluid inertances and capacitances of each fluidic circuit, to reduce the transmitted pitch-link loads. The different circuit designs result in transmitted pitch-link loads reduction at up to three main rotor harmonics. The simulation results show loads reduction at the targeted out-of-phase and in-phase harmonics of up to 88% and 93%, respectively. Experimental validation of two of the fluidic circuits demonstrates loads reduction of up to 89% at the out-of-phase isolation frequencies and up to 81% at the in-phase isolation frequencies.

Original languageEnglish (US)
Article number042005
JournalJournal of the American Helicopter Society
Volume59
Issue number4
DOIs
StatePublished - Oct 1 2014

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Fluidics
Fluidic devices
Networks (circuits)
Analytical models
Aerodynamics
Capacitance
Rotors
Fluids

All Science Journal Classification (ASJC) codes

  • Aerospace Engineering
  • Materials Science(all)
  • Mechanical Engineering
  • Mechanics of Materials

Cite this

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title = "Coupled pitch links for multiharmonic isolation using fluidic circuits",
abstract = "Replacing stiff pitch links on rotorcraft with coupled fluidic devices has the potential to reduce the aerodynamic blade loads transmitted through the pitch links to the swashplate. Analytical models of two fluidic devices coupled with three different fluidic circuits are derived. These passive fluidlastic systems are tuned, by varying the fluid inertances and capacitances of each fluidic circuit, to reduce the transmitted pitch-link loads. The different circuit designs result in transmitted pitch-link loads reduction at up to three main rotor harmonics. The simulation results show loads reduction at the targeted out-of-phase and in-phase harmonics of up to 88{\%} and 93{\%}, respectively. Experimental validation of two of the fluidic circuits demonstrates loads reduction of up to 89{\%} at the out-of-phase isolation frequencies and up to 81{\%} at the in-phase isolation frequencies.",
author = "Scarborough, {Lloyd H.} and Rahn, {Christopher D.} and Edward Smith and Koudela, {Kevin L.}",
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Coupled pitch links for multiharmonic isolation using fluidic circuits. / Scarborough, Lloyd H.; Rahn, Christopher D.; Smith, Edward; Koudela, Kevin L.

In: Journal of the American Helicopter Society, Vol. 59, No. 4, 042005, 01.10.2014.

Research output: Contribution to journalArticle

TY - JOUR

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AU - Scarborough, Lloyd H.

AU - Rahn, Christopher D.

AU - Smith, Edward

AU - Koudela, Kevin L.

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