A5075709012- Acoustic Wave Phenomena Research
- Aerodynamics and Acoustics in Jet Flows
- Vehicle Noise and Vibration Control
- Wind and Air Flow Studies
- Combustion and flame dynamics
- Structural Health Monitoring Techniques
- Aerodynamics and Fluid Dynamics Research
- Cavitation Phenomena in Pumps
- Fluid Dynamics and Turbulent Flows
- Speech and Audio Processing
- Wood Treatment and Properties
- Wind Energy Research and Development
- Stoma care and complications
- Meteorological Phenomena and Simulations
- Noise Effects and Management
- Advanced Adaptive Filtering Techniques
- Tropical and Extratropical Cyclones Research
- Music Technology and Sound Studies
- Turbomachinery Performance and Optimization
- Computational Fluid Dynamics and Aerodynamics
- Structural Engineering and Vibration Analysis
- Structural Load-Bearing Analysis
- Underwater Acoustics Research
- Pressure Ulcer Prevention and Management
- Colorectal Cancer Surgical Treatments
University of Auckland
2016-2024
Ottawa University
2022
Parkland Health & Hospital System
2018-2020
MedStar Washington Hospital Center
2020
University of Southampton
2009-2019
MedStar Health
2016-2018
Christiana Care Health System
2017
University of Canterbury
2006-2009
This paper describes the extension of a wave and finite element (WFE) method to prediction noise transmission through, radiation from, infinite panels. The WFE starts with conventional model small segment panel. For given frequency, mass stiffness matrices are used form structural dynamic matrix. acoustic responses fluids surrounding structure modelled analytically. matrix is post-processed using periodic theory, coupled those fluids. total obtain response medium an incident pressure....
This paper presents a new formulation for trailing edge noise radiation from rotating blades based on an analytical solution of the convective wave equation. It accounts distributed loading and effect mean flow spanwise wavenumber. A commonly used theory due to Schlinker Amiet predicts blades. However, different versions exist; it is not known which version correct one, what range validity is. addresses both questions by deriving Amiet's in simple way comparing with formulation, using model...
A study is made of the noise levels and spectral characteristics three contra-rotating propeller rigs: rig 140 tested in 1989, 145 build 1 2008, 2 2010. We use tone deletion techniques, applied to inflow microphone data, show relative importance broadband tones with increasing frequency and, particular, that by time we reach only moderate frequencies, one third octave spectra become dominated components. also continues be important as blade speed thrust are varied these present on both...
This paper presents a detailed investigation of tonal noise produced by an unmanned aerial vehicle propeller operating with circular strut mounted just downstream. Experimental measurements the acoustic pressure in near- and far-fields are presented, it is observed that measured signals contain strong impulse caused propeller–strut interaction. The magnitude shape this vary significantly observer location. It was also these impulses reduced increasing distance between strut. In order to...
In anticipation of a major construction project in an urban New Zealand zoo, study was initiated to assess the response noise selected animal species (elephant, giraffe, emu and alligator) previously observed be sensitive this kind noise. The overall aim detect any signs aversive responses enable keepers recognize these take necessary mitigating actions during period. experimental approach involved creation acoustic maps each focal enclosure, series 90-min video recordings animals’ behavior...
This paper presents the results of a study evaluating human perception noise produced by four different small quadcopter unmanned aerial vehicles (UAVs). utilised measurements and recordings UAVs in hover constant-speed flight at fixed altitude. Measurements made using ½″ microphone were used to calculate range metrics for each event. Noise also spherical array (an Eigenmike system). The reproduced 3D sound reproduction system installed large anechoic chamber located University Auckland....
An attempt to record speech signals using an array of directional microphones carried by unmanned aerial vehicle (UAV) is reported. The enhancement algorithm estimates the power spectral densities (PSD) target and rotor noise which are used calculate a Wiener filter for extracting speech. calculated then applied output beamforming implemented on microphone signals. proposed was tested prototype UAV equipped with each orientated in different directions. experimental results revealed that...
An analytical model is presented for the wake interaction tones produced by a contra-rotating propeller. We re-cast usual far-field radiation formulae as double integral over nominal propeller source annulus. Assuming that number of blades on both propellers large, we evaluate asymptotically in terms its leading-order contributions from interior stationary or boundary critical points which represent specific locations annulus dominate sound radiation. The asymptotic approach powerful...
This paper investigates the interaction tones produced by periodic unsteady loading on blades of two different contra-rotating unmanned aerial vehicle (UAV) rotor systems using computational, analytical, and experimental methods. Computational fluid dynamics (CFD) simulations are used to predict visualize flow through rotors. Semi-analytical models also presented for predicting portion this due each blade with bound potential field adjacent rotor. A comparison predicted CFD semi-analytical...
This paper investigates the effect of an acoustically rigid shroud on tonal noise produced by unmanned aerial vehicle (UAV) propeller. Enclosing propeller with a alters steady loading blades, thereby changing tones radiated from sources surface. In this it is shown that time-average rotating pressure field inner surface also makes significant contribution to noise. The aerodynamics shrouded and isolated was investigated using computational fluid dynamics (CFD) simulations. thickness...
An experimental investigation of the noise produced by a shrouded propeller interacting with grid-generated turbulence in an anechoic wind tunnel is presented. Inflow statistics and far-field directivity were measured. Measured inflow operating parameters used theoretical model to predict turbulent spectra directivity. The uses rapid distortion theory calculate distorted field at plane. unsteady loading on rotating blades calculated using isolated blade response functions. radiated then...