A5068126440- Aerodynamics and Acoustics in Jet Flows
- Acoustic Wave Phenomena Research
- Fluid Dynamics and Turbulent Flows
- Wind and Air Flow Studies
- Metamaterials and Metasurfaces Applications
- Aerodynamics and Fluid Dynamics Research
- Noise Effects and Management
- Particle Dynamics in Fluid Flows
- Fluid Dynamics and Vibration Analysis
- Combustion and flame dynamics
- Speech and Audio Processing
- Flow Measurement and Analysis
- Geophysical Methods and Applications
- Ultrasonics and Acoustic Wave Propagation
- Underwater Acoustics Research
- Icing and De-icing Technologies
- Heat Transfer Mechanisms
Virginia Tech
2020-2025
University of Exeter
2024
This study presents wall pressure sensors based on wall-flush Kevlar-covered cavities. The sensor dynamic response is characterized using a variety of acoustic and flow experiments, including disturbance quantification performed wall-parallel particle image velocimetry. Various configurations are studied to understand the relation between cavity shape Kevlar scrim response. Using localized excitation study, sensor’s spatial sensitivity characterized, mathematical model estimate spectrum...
Abstract Today, acoustic metamaterials form a core area of metamaterial research. They offer bespoke wave control, achievable through their rationally designed structure and are at the forefront applications commercialisation. find purpose across science defence sectors in filtering, sensing, communications, energy harvesting, thermal emission aeroacoustics, to name but few. enjoy success metropolitan environments with designer audio noise mitigation falling within remit; technologies...
Locating a sound source through the disruptive turbulent boundary layer's pressure fluctuations is of great difficulty in aero/hydroacoustic applications.Conventional phased microphone arrays have trouble with this task because their diaphragms are exposed to excess noise presented by these fluctuations.In paper, meander-style metasurface was modified make it flow-compatible.A sub-resonant sensor array also designed filter out convective and improve signal ratio.These novel designs were...
This experiment demonstrates the generation of trapped acoustic surface waves excited by a turbulent flow source through coupling pressure fluctuations at interface between an metamaterial and environment. The flow, which behaves as stochastic source, was interfaced with metasurface waveguide stationed in quiescent environment via single Kevlar-covered cavity, ensured no significant disturbance to flow. produced mode evanescent diffractive field. surface, its dispersion determined geometry....
Low-wavenumber pressure fluctuations generated by turbulent boundary layers are the source of both flow-generated sound and structural vibration in many applications. However, form origin these poorly understood, not least because measurement this component wall spectrum is especially challenging. This paper describes a new method for low-wavenumber using arrays resonating sensors inspired acoustic metamaterials. Measurements made array high Reynolds number shows sub-convective components...
A Kevlar-covered acoustic resonator-based cavity sensor is introduced to measure low-wavenumber pressure fluctuations in a turbulent boundary layer. These sensors have an inherent capability filter the convective based on their physical dimensions, specifically extent streamwise and spanwise directions. This study aims demonstrate spatial sensitivity behavior of these show viability towards wall measurements by revealing lack effects flow over using time-resolved parallel visualization...
View Video Presentation: https://doi.org/10.2514/6.2023-3337.vid Spanwise homogeneous turbulent boundary layers convect groups of flow structures that move with similar momentum, often called coherent structures. These remain statistically as they get convected downstream. The length scales such vary the wall-normal distance layer. Large-scale motions on order ~20 layer thicknesses, termed superstructures, are conjectured to be present in outer However, Particle Image Velocimetry (PIV) data...
Vehicle flow surfaces subject to turbulent boundary layer pressure fluctuations experience flow-induced sound and structural vibrations. Low-wavenumber surface are the source of such excitations. This paper utilizes a novel method quantify low wavenumber on flat plate subjected in presence range gradients. An array based Kevlar-covered resonating cavity sensors is employed take non-intrusive measurements at high Reynolds numbers. Measurements reveal form subconvective wavenumber-frequency...
This experiment demonstrated the generation of trapped acoustic surface waves excited by a turbulent flow source through coupling pressure fluctuations at interface between an metamaterial and environment. The flow, which behaves as stochastic source, was produced using fully developed wall jet. plate in jet perforated with single cavity. On flow-side it capped Kevlar weave to ensure cavity did not significantly disturb whilst on adjacent side open quiescent (static) through-cavity opening,...
View Video Presentation: https://doi.org/10.2514/6.2023-3828.vid Aeroacoustic measurements in closed-section wind tunnels often employ phased microphone arrays that are mounted flush to the wall of test section. Phased can measure directivity multiple acoustic sources within a sound field across all frequencies, but require dozens microphones typical applications. Furthermore, turbulent boundary layer developed by engulf loud pressure fluctuations drown out acoustics trying be measured. This...