Title: Are the trains getting quieter?
The paper outlines the tremendous work done in Australia over the last fifteen years to better understand rail noise and devise mitigation strategies. Developments in curve noise, locomotive noise, and general rolling noise are discussed, both in understanding the root causes of these issues as occur in Australia, and in how to reduce these types of noise. The paper explores the successes, failures, and untapped opportunities in regards to implementing noise mitigation, with an emphasis on understanding the broader rail system and the drivers of rolling stock and network operators, and how acousticians can leverage this broader context. Lastly, we examine rail noise mitigation through the lens of opportunity cost. With reference to recent examples, and the current rail infrastructure boom, we pose a challenge to regulators, planners, operators and proponents to be open to different ways of implementing mitigation.
Dave Hanson is a Director of Acoustic Studio with more than 20 years’ of experience in rail across a wide range of fields. Dave’s career started as an engineering cadet with A Goninan and Co (now UGL) building locomotives, wagons and passenger cars. After graduating with a Bachelor of Mechanical Engineering from the University of Newcastle, Dave worked as a reliability engineer at Maintrain in Sydney before returning to studies and being awarded a PhD by the University of NSW in 2007. Dave then worked for five years for Sinclair Knight Merz in their Advanced Analysis and Test team, delivering a range of rail noise and vibration projects including the first full-scale transfer path analysis on a rail vehicle in Australia. He moved to RailCorp in 2011 as Technical Specialist Noise and Vibration, and then transferred to Transport for NSW in 2013, becoming Senior Manager Freight Performance in 2017. Dave has in-depth experience in rolling stock, track and wheel/rail interface issues associated with noise and vibration from freight and passenger heavy rail and light rail. Dave’s experience includes curve noise management, locomotive noise mitigation, rail grinding and rail friction management. He was an author of the Transport for NSW Engineering Standards for wagon steering and rail lubrication, and was a member of the technical committee for AS 7641 Rail Gauge Corner Lubrication Management. Dave has authored or co-authored numerous technical papers and is a reviewer for several journals in the field of rail noise.
Title: Flow-induced noise regimes of a three-dimensional airfoil
The flow-induced noise produced by a surface-mounted three-dimensional (or finite length) airfoil is important for many aerodynamic and hydrodynamic applications. Examples include wing-fuselage junctions, turbomachinery blade, rotor tip and end-wall flows, and ship appendage and hull-junction flows. This presentation provides an overview of the three-dimensional airfoil noise program at UNSW Sydney. In general, there are four flow regimes for a three-dimensional airfoil. These are the airfoil-wall junction flow featuring a horseshoe vortex that wraps around the airfoil base; turbulent flow interaction with the leading edge; trailing edge flow whose structure depends upon the Reynolds number; and the tip flow that consists of vortices that form as the flow wraps around the free-end of the airfoil. The acoustic signature and turbulent noise sources associated with each of these flow regimes will be examined using anechoic wind tunnel measurements obtained with microphone array, unsteady surface pressure and turbulence measurement methods.
Danielle Moreau is a Senior Lecturer in the School of Mechanical and Manufacturing Engineering at the University of New South Wales. She obtained her BE(hons) and PhD from the School of Mechanical Engineering at the University of Adelaide in 2005 and 2010, respectively. Danielle’s research is in the field of aeroacoustics or the understanding and control of flow-induced noise. She investigates innovative noise control solutions for aircraft, wind turbines, propellers, fans, UAVs and submarines. Her major research contributions have been in (i) wall-mounted finite airfoil aeroacoustics, (ii) airfoil trailing edge noise production and control and (iii) bluff body flow noise.
Title: Modelling of acoustic metamaterials
Acoustic metamaterials are rationally designed composites for which the dynamic properties go beyond those of their static ingredients. The basic structure of an acoustic metamaterial is composed of a lattice of resonant scatterers embedded in an elastic matrix. This composite design facilitates strong acoustic coupling between scatterers. Due to their extraordinary wave manipulation capabilities and the tremendous progress in fabrication technology, acoustic metamaterials are becoming immensely popular for noise control. However, the analytical and numerical treatment of acoustic metamaterials is still a challenging undertaking and this necessitates development of some simplified physics-based models. In this talk, we present the results derived from these models and demonstrate how the proposed framework can be applied for the tailored design of acoustic metamaterials for vibroacoustics coatings.
Alex Skvortsov is a Principal Scientist in the Maritime Division of the Defence Science and Technology Group. He obtained his PhD from the Moscow University of Applied Physics and Technology in 1987, on the topic of nonlinear phenomena in acoustics and vortex-sound interactions. Alex has extensive experience in defence-related and defence-sponsored projects. His research activities include stealth materials, complex vibration systems, aeroacoustics, nonlinear wave dynamics and epidemics modelling.
Title: Wind farm noise prevalence, annoyance, and sleep disturbance
Despite widespread community acceptance of renewable power generation to reduce CO2 emissions and reduce natural resource impacts, large-scale expansion of wind farms has prompted significant community debate regarding adverse health impacts of wind farm noise (WFN). The main concerns include annoyance, sleep disturbance, psychological distress, and reduced health-related quality of life. Our research has aimed to investigate these issues by identifying, quantifying, and characterising the signal components of WFN that are responsible for annoyance and sleep disturbance. We carried out 1-year-long acoustic and meteorological measurements at three residences located near different wind farms, allowing detailed characterisation of WFN and its relationship with meteorological conditions. We also conducted a range of laboratory listening tests that focused on various WFN features such as amplitude modulation, tonality, low frequency noise and infrasound. Additionally, we used direct electroencephalographic (EEG) and cardiovascular measurements to systematically evaluate the sleep disruption and physiological activation response characteristics of wind farm noise during sleep. This paper presents a detailed overview of the preliminary results from our recent projects, providing insights into the prevalence of potentially disturbing WFN characteristics and the corresponding annoyance and sleep disturbance responses from four different participant groups, including noise sensitive and non-sensitive individuals.
Dr Kristy Hansen is a DECRA Researcher and Senior Lecturer at Flinders University with 9 years of experience in wind farm noise research. She is chief investigator on ARC and NHMRC projects that aim to identify the potentially annoying and sleep disruptive components of wind farm noise. She has co-authored two scholarly books, including one on wind farm noise that was published by Wiley in 2017 and another on general acoustics and acoustic problem solving which was published by CRC Press in 2021. Kristy’s research focuses on wind farm noise and other types of environmental noise and she has extensive experience in acoustic and vibration measurements, advanced signal processing, noise propagation modelling, noise synthesis and listening test design. Her recent contributions have included (i) machine-learning-based algorithms to detect specific components in acoustic and sleep signals, (ii) detailed characterisation of amplitude modulation prevalence and magnitude at noise sensitive receivers, and (iii) wind farm noise propagation modelling and uncertainty analysis. Kristy has authored or co-authored over 50 peer-reviewed publications and recently participated in the development of the new IEC technical standard, PT 61400-11-2, on the measurement of wind farm noise at receptor locations.
Title: Making waves in vibration measurement with laser Doppler vibrometry
The impact of the invention of the laser cannot be over-stated. In vibration and acoustics engineering, the laser Doppler vibrometer has revolutionised the means by which scientists and engineers can interpret and control the natural and man-made environment, both on and off the planet. Combining high sensitivity, dynamic and frequency ranges, non-invasiveness and high spatial resolution, laser Doppler vibrometers (LDVs) have received significant and increasing attention in both research and industry. This talk will therefore investigate the origins, working principles and evolution of LDVs, focusing on industrially relevant, practical applications. Particular focus will be on modelling of the measurement for multiple beam configurations and arbitrary, six degree-of-freedom target vibration and on overcoming specific challenges associated with making successful measurement campaigns in challenging scenarios. Now traditional capabilities such as determining vibration directly from rotating systems, from light/micro- structures or of waves passing through and perturbed by damaged structures will be addressed in detail. Particular attention will be paid to the importance of and mitigation the laser speckle effect. More contemporary, UTS-led topics including the use of LDVs as remote noise control error signal “listening” devices as well as the removal of another form of “self-noise” due to the vibration of the instrument sensor head itself will receive significant attention, in particular in the context of the incorporation and fusion of these incredible devices into autonomous systems for the enhanced, trusted determination and monitoring of the dynamic characteristics of remote infrastructure and environments.
Dr Benjamin Halkon is an industrially experienced experimental dynamics and instrumentation expert and Senior Lecturer in the School of Mechanical and Mechatronic Engineering at University of Technology Sydney. Ben is a core member of the Centre for Audio, Acoustics and Vibration, primarily based at UTS Tech Lab where he has established and now co-directs the Vibration Laboratory which includes unique non-contact vibration measurement capabilities. Ben currently co-supervises a growing team of junior researchers, continues to secure industrially oriented funded research projects while publishing excellent research outputs and takes a full role in and recognises the importance of teaching and learning.