Small Business Innovation Research/Small Business Tech Transfer
Continuous-Scan Phased Array Measurement Methods for Turbofan Engine Acoustic Testing
Project Description
To allow aviation growth to continue in the face of increasingly stringent noise pollution standards, new aircraft engines must be designed with noise performance as a principal constraint. Technologies to realize future propulsion noise reduction will require detailed experimental characterization and diagnosis of the acoustic mechanisms and sources within an engine system or component. ATA Engineering, Inc. (ATA) proposes an SBIR project to further develop and validate methods for obtaining phased array acoustic data from complex distributed noise sources using continuously moving, or continuous-scan (CS) microphones in conjunction with state-of-the-art phase-referencing techniques. The benefits of the CS method include (1) effectively infinite spatial resolution, as the sound field cross-spectrum may be described between any two locations along the scan trajectory, (2) preservation of phase data for improved source and propagation modeling, including beamforming (BF) and acoustical holography (AH), (3) significant reduction of test data acquisition time (potentially two to ten times faster) per operational point, and consequently either (4) reduced test operational cost, or (5) the opportunity to screen more design concepts within a given budget. The Phase II effort will use subscale aeroacoustic testing to validate the novel continuous-scan beamforming (CSBF) measurement techniques with the aim of eventual implementation in NASA acoustic wind tunnel and free-jet testing facilities. ATA will also formalize a CS software toolkit for data processing and visualization and design a full-scale array concept for a candidate NASA wind tunnel facility.
More »
Anticipated Benefits
ATA believes that significant benefits could be achieved through implementing the CS acoustic measurement technology in NASA wind tunnel and free-jet facilities. The resulting capability would support noise reduction goals set forth in the Aeronautics Research Mission Directorate's (ARMD's) Strategic Implementation Plan (SIP). In particular, Strategic Thrust 3: Ultra-Efficient Commercial Vehicles establishes noise improvement margins (relative to the FAA Stage 4 noise limit) of −32 dB, −42 dB, and −52 dB, for N+1, N+2, and N+3 future aircraft technology generations, respectively. ATA's technology will support progress toward all four NASA long-term research themes under the Subsonic Transport portion of the strategic thrust (3A): Ultra-efficient airframes, Ultra-efficient propulsion, Ultra-efficient vehicle system integration, and Modeling, simulation, and test capability research. In the coming decades, progress towards these objectives will be accomplished through research conducted in NASA and commercial experimental facilities. Examples of aeroacoustic measurement facilities that could readily adapt the technology include the 9' x 15' Low Speed Wind Tunnel (LSWT), Aero-Acoustic Propulsion Laboratory (AAPL), and 14' x 22' Subsonic Wind Tunnel.
Community noise exposure continues to be a significant issue near airports, confining growth and impacting quality of life and health of those affected. To counteract growing exposure, ever more stringent noise standards are expected to be implemented by regulatory agencies in the certification of aircraft. These standards are predicated on the discovery of new technologies aimed at reducing aircraft and engine noise. Further noise performance improvements will likely be asymptotic, with incremental improvements resulting in only modest noise reduction. Thus, innovative measurement technologies to better identify and diagnose noise sources within the aircraft and engine are necessary, particularly for the subscale-size test articles and low-SNR environments of wind tunnel testing. ATA believes there is a significant market opportunity for the enhanced CS toolset through adoption at engine manufacturers, airframers, and international aviation authorities. Beyond aviation, CS tools and methods will be applicable to wind turbine, automotive, and industrial noise. More »
Community noise exposure continues to be a significant issue near airports, confining growth and impacting quality of life and health of those affected. To counteract growing exposure, ever more stringent noise standards are expected to be implemented by regulatory agencies in the certification of aircraft. These standards are predicated on the discovery of new technologies aimed at reducing aircraft and engine noise. Further noise performance improvements will likely be asymptotic, with incremental improvements resulting in only modest noise reduction. Thus, innovative measurement technologies to better identify and diagnose noise sources within the aircraft and engine are necessary, particularly for the subscale-size test articles and low-SNR environments of wind tunnel testing. ATA believes there is a significant market opportunity for the enhanced CS toolset through adoption at engine manufacturers, airframers, and international aviation authorities. Beyond aviation, CS tools and methods will be applicable to wind turbine, automotive, and industrial noise. More »
Project Library
Primary U.S. Work Locations and Key Partners
| Organizations Performing Work | Role | Type | Location |
|---|---|---|---|
| ATA Engineering, Inc. | Lead Organization | Industry | San Diego, California |
Glenn Research Center
(GRC)
|
Supporting Organization | NASA Center | Cleveland, Ohio |
Primary U.S. Work Locations
-
California
-
Ohio
Suggest an Edit
Recommend changes and additions to this project record.