Testing of SMA-enabled active chevron prototypes under representative flow conditions

Control of jet noise continues to be an important research topic. Exhaust-nozzle chevrons have been shown to reduce jet noise, but parametric effects are not well understood. Additionally, thrust loss due to chevrons at cruise suggests significant benefit from active chevrons. The focus of this study is development of an active chevron concept for the primary purpose of parametric studies for jet noise reduction in the laboratory and secondarily for technology development to leverage for full scale systems. The active chevron concept employed in this work consists of a laminated composite structure with embedded shape memory alloy (SMA) actuators, termed a SMA hybrid composite (SMAHC). SMA actuators are embedded on one side of the neutral axis of the structure such that thermal excitation, via joule heating, generates a moment and deflects the structure. The performance of two active chevron concepts is demonstrated in the presence of representative flow conditions. One of the concepts is shown to possess significant advantages for the proposed application and is selected for further development. Fabrication and design changes are described and shown to produce a chevron prototype that meets the performance objectives.

[1]  Russell H. Thomas,et al.  COMPUTATIONAL ANALYSIS OF A PYLON-CHEVRON CORE NOZZLE INTERACTION , 2001 .

[2]  Cynthia L. Lach,et al.  Fabrication and characterization of SMA hybrid composites , 2001, SPIE Smart Structures and Materials + Nondestructive Evaluation and Health Monitoring.

[3]  James Bridges,et al.  Acoustics and Trust of Separate-Flow Exhaust Nozzles With Mixing Devices for High-Bypass-Ratio Engines , 2000 .

[4]  Vinod G. Mengle,et al.  Jet Noise Characteristics of Chevrons in Internally Mixed Nozzles , 2005 .

[5]  Ephraim Gutmark,et al.  Far-Field Acoustic Investigation into Chevron Nozzle Mechanisms and Trends , 2005 .

[6]  Clifford A. Brown,et al.  Parametric Testing of Chevrons on Single Flow Hot Jets , 2004 .

[7]  Randolph H. Cabell,et al.  Design, fabrication, and testing of a SMA hybrid composite jet engine chevron , 2006, SPIE Smart Structures and Materials + Nondestructive Evaluation and Health Monitoring.

[8]  Ramesh Chandra,et al.  Active shape control of composite blades using shape memory actuation , 2001 .

[9]  Amr M. Baz,et al.  Shape control of NITINOL-reinforced composite beams , 1994, Smart Structures.

[10]  Gary A. Fleming,et al.  Modeling, Fabrication, and Testing of a SMA Hybrid Composite Jet Engine Chevron Concept , 2006 .

[11]  Randolph H. Cabell,et al.  Development of a SMA hybrid composite jet engine chevron concept , 2007, SPIE Smart Structures and Materials + Nondestructive Evaluation and Health Monitoring.

[12]  C. M. Wayman,et al.  Shape-Memory Materials , 2018 .

[13]  Travis L. Turner,et al.  Structural acoustic response of a shape memory alloy hybrid composite panel (lessons learned) , 2002, SPIE Smart Structures and Materials + Nondestructive Evaluation and Health Monitoring.

[14]  Ephraim Gutmark,et al.  A PIV Flow Field Investigation of Chevron Nozzle Mechanisms , 2004 .

[15]  Vinod G. Mengle,et al.  Relative Clocking of Enhanced Mixing Devices for Jet Noise Benefit , 2005 .

[16]  James H. Mabe,et al.  Design and Control of a Morphing Chevron for Takeoff and Cruise Noise Reduction , 2005 .

[17]  K. Chawla,et al.  Mechanical Behavior of Materials , 1998 .

[18]  Travis L. Turner,et al.  A New Thermoelastic Model for Analysis of Shape Memory Alloy Hybrid Composites , 2000 .

[19]  Kevin W. Kinzie,et al.  Turbulent Flow Field Measurements of Separate Flow Round and Chevron Nozzles with Pylon Interaction Using Particle Image Velocimetry , 2004 .

[20]  Samuel P. Kounaves,et al.  Fabrication and characterization , 1991 .

[21]  Hugh Alan Bruck,et al.  Repeatable bending actuation in polyurethanes using opposing embedded one-way shape memory alloy wires exhibiting large deformation recovery , 2002 .

[22]  Russell H. Thomas,et al.  Computational and Experimental Flow Field Analyses of Separate Flow Chevron Nozzles and Pylon Interaction , 2003 .

[23]  J. Ro,et al.  Shape control of NITINOL-reinforced composite beams☆ , 2000 .

[24]  Nam Seo Goo,et al.  Shape changes by coupled bending and twisting of shape-memory-alloy-embedded composite beams , 2002 .

[25]  Travis L. Turner,et al.  Analysis of SMA Hybrid Composite Structures in MSC.Nastran and ABAQUS , 2007 .

[26]  George W. Butler,et al.  Subsonic Jet Noise Reduction Variable Geometry Chevron , 2004 .

[27]  Ephraim Gutmark,et al.  Acoustic Investigation of a High Bypass Ratio Separate Flow Exhaust System with Chevrons , 2004 .

[28]  Ephraim Gutmark,et al.  A Near -Field Investigation of Chevron Nozzle Mechanisms , 2003 .

[29]  James H. Mabe,et al.  Feedback Control of a Morphing Chevron for Takeoff and Cruise Noise Reduction , 2004 .

[30]  T. Turner.  Thermomechanical Response of Shape Memory Alloy Hybrid Composites. Degree awarded by Virginia Polytechnic Inst. and State Univ., Blackburg, Virginia, Nov. 2000. , 2013 .