Description: Current methods for identification of aircraft noise sources, such as near-field acoustical holography and beam forming techniques, involve the use of pressure probes or microphone arrays to measure the radiated sound field. However, those techniques are intrusive, bandwidth limited, time consuming to implement, require extensive data processing and the resulting data may ultimately generate false results in the form of pseudo (noise) sources. Advanced Systems & Technologies Inc. proposes an optical non-contact sensor fusion concept which, for the first time, enables direct capture and observation of full-field non-stationary dynamic structural vibrations (SV) and unsteady radiated sound fields or transient flow fields around the structure of interest. SV depict the flow of energy in a structure and provides an unambiguous identification of structural noise sources and sinks. Additionally, the ability to capture and correlate the acoustic/flow field data with the structure borne intensity, offers an unprecedented and rapid diagnostic capability for noise source characterization and evaluation of noise abatement systems. In addition to being non-intrusive the measurements are fast, can be made at operationally relevant bandwidths, which extend to the ultrasonic domain, and provide deeper insight into the complex structural dynamics which are the root cause of noise emission.

Benefits: The ICARUSV contributes towards current and future noise reduction goals by providing a diagnostic tool for evaluation of a wide range of aircraft structures designed to effect noise reduction. Examples of applications include testing of continuous mould line wing structures, drooped leading edge, active flow control, adaptive and flexible wing structures, smart cheverons, and toboggan fairings. Related applications include evaluation of engine noise reduction systems such as Ultra High Bypass engines, distortion-tolerant fans and variable fan nozzles. The ability to visualize energy flow paths between sources and sinks on the structure will elucidate the contribution of specific design features in determining these paths and suggest design modifications which mitigate or redirect this energy away from specific locations. ICARUSV also offers a new tool for identification of vehicle specific aero-elastic instabilities and for fundamental aeronautic studies related to ground testing, wind tunnel tests, and flight experiments.

The parallel sensor architecture of the ICARUSV overcomes limitations in existing technology, introducing, for the first time, a true imaging modality to the laser Doppler vibrometer (LDV). The ICARUSV concept and related instruments is thus anticipated to appeal to a broad spectrum of applications and industries where existing commercial single beam LDV�s are currently employed. In addition to performing routine vibration measurements much more efficiently (orders of magnitude faster than LDV) the imaging modality of the ICARUSV is anticipated to find new diagnostic capability beyond those of traditional LDV, including aerospace, automotive, electronics and industrial plants applications. Numerous industries (automotive, aerospace, medical and computer electronics) employ LDV for modal vibration analyses. In addition to modal analysis, the ICARUSV would target the market represented by non-destructive testing in the marine, aviation and space industries and, in particular, the non-destructive inspection in manufacture and maintenance of deployed military systems.