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Dynamic Analysis for a Geared Turbofan Engine with Variable Area Fan NozzleAggressive design goals have been set for future aero-propulsion systems with regards to fuel economy, noise, and emissions. To meet these challenging goals, advanced propulsion concepts are being explored and current operating margins are being re-evaluated to find additional concessions that can be made. One advanced propulsion concept being evaluated is a geared turbofan with a variable area fan nozzle (VAFN), developed by NASA. This engine features a small core, a fan driven by the low pressure turbine through a reduction gearbox, and a shape memory alloy (SMA)-actuated VAFN. The VAFN is designed to allow both a small exit area for efficient operation at cruise, while being able to open wider at high power conditions to reduce backpressure on the fan and ensure a safe level of stall margin is maintained. The VAFN is actuated via a SMA-based system instead of a conventional system to decrease overall weight of the system, however, SMA-based actuators respond relatively slowly, which introduces dynamic issues that are investigated in this work. This paper describes both a control system designed specifically for issues associated with SMAs, and dynamic analysis of the geared turbofan VAFN with the SMA actuators. Also, some future recommendations are provided for this type of propulsion system.
Document ID
Document Type
Conference Paper
Csank, Jeffrey T.
(NASA Glenn Research Center Cleveland, OH United States)
Thomas, George L.
(Vantage Partners, LLC Cleveland, OH, United States)
Date Acquired
September 11, 2017
Publication Date
July 10, 2017
Subject Category
Aircraft Propulsion And Power
Report/Patent Number
Meeting Information
2017 AIAA/SAE/ASEE Joint Propulsion Conference(Atlanta, GA)
Funding Number(s)
WBS: WBS 109492.
Distribution Limits
Public Use Permitted.
Geared Turbofan
Variable Area Fan Nozzle
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