A Scalable Acoustic Vector Measurement System For Characterizing Jet Aeroacoustics
Abstract
The proposed instrumentation is an acoustic vector-based measurement system capable of characterizing jet aeroacoustic sources and f,ields. The proposed system elucidates noise generation mechanisms and enables more complete physics-based studies of noise reduction, technologies for tactical jet engines. Reduced tactical jet noise lessens naval community and environmental impact and the risk of,warfighter hearing loss. A reduced noise footprint and improved warfighter health and safety will increase operations tempo and impr,ove military readiness. This unique measurement system results from 15 years of research and development and is comprised of state,-of-the-art hardware, acquisition and analysis software, and signal processing theory. High-fidelity microphones, capable of measure,ments in harsh, high sound-intensity environments, are arranged in several multi-microphone probes,ressure and vector particle velocity in the region spanning the jet noise sources. From these data, numerous other acoustic quantiti,es important to source and radiation characteristics are calculated to study flow-acoustic coupling and to provide advanced benchmar,ks for computational simulations. The system takes advantage of a PI-developed signal processing method that produces accurate vecto,reconfigured and optimized to uncover aeroacoustic similarities and differences across all jet scales: from laboratory-scale nozzles, to full military engines to large-nozzle rocket plumes. The system will collaboratively enhance DoD research interests in jet aero,acoustics in search of the underlying physics of noise generation and radiation from highly heated, supersonic jet flows, and to mor,e deeply investigate performance of potential noise control solutions. This portable, advanced acoustics measurement capability will, be used to investigate near-field acoustics in scale-model facilities and at full scale. This system enables researchers to obtain,greater information from measurements, by linking flow-field diagnostics with advanced, near-field characterization. The PIs develo,pment of these advanced acoustics methods and significant analysis of full-scale tactical aircraft data can be leveraged to design e,xperiments that more closely mimic full-scale radiation characteristics and pursue optimal noise reduction strategies. Multiple opp,ortunities for system use that support DoD research objectives are upcoming. At the laboratory-scale, a collaborative ONR research p,rogram (N00014-21-1-2069) will be used to collect data from an afterburning jet rig and connect it to near-field acoustic data from,an installed F404 engine. This will help validate the newly developed, ONR-funded rig and enable deeper physical studies. At full-sc,ale, future noise reduction technology tests will benefit from advanced source characterizationto better investigate changes in sour,ce properties. Near-term rocket plume measurement opportunities applicable to weapons systems and future propulsion technologies , also exist. The DURIP system, which has an expected useful lifetime of 10-25 years for its components, provides significantly enha,nced education opportunities for graduate and undergraduate researchers. Students will be educated in aeroacoustic measurements, adv,anced measurement hardware, jet noise theory, acoustic signal processing, coding and archiving practices, and working in collaborati,ve research environments. Thus, this DURIP system will not only be used to improve military readiness, but it also provides next-gen,eration DoD scientists with critical skills to help enhance our tactical advantage.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Mar 05, 2022
- Source ID
- N000142212220
Entities
People
- Kent L Gee
Organizations
- Brigham Young University
- Office of Naval Research
- United States Navy