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Dr. John Kennedy
Assistant Professor, Mechanical, Manuf & Biomedical Eng

Biography

Dr. John Kennedy is Assistant Professor in Vibrations, Acoustics and Dynamics at Trinity College Dublin. His research career began on the aero-acoustics of jets with mixing enhancing features. Since then he has gone on to work on a range of aero-acoustic problems in transport applications. His research has applied advanced correlation and spectral analysis techniques to experimental data of turbulence (LDV, X-hotwire and high speed PIV) and included advanced beamforming and partial coherence techniques for source localisation using microphone array data. He has also engaged in interdisciplinary research with psychologists from the University of Bath and the University of Aberystwyth into the influence of noise exposure on human performance in transport applications including hazard detection, risk perception and annoyance.

He has been the scientific coordinator and lead technical manager of the Clean Sky projects WENEMOR, ALLEGRA and ARTIC. His responsibilities on these projects included the conduct of Preliminary and Critical Design Reviews, test planning and supervision of the wind tunnel test campaigns. He was also the lead research for all scientific deliverables on these projects.

He is the Irish coordinator for the industrially focused Institute of Acoustics' Diploma in Acoustics and Noise Control. He has acted as a reviewer for a number in high profile journals in aero-acoustics including the Journal of Sound and Vibration, the Journal of the Acoustical Society of America, Acta Acoustica and the International Journal of Aeroacoustics. His work in transport aero-acoustics has led to press releases by the Acoustical Society of America and the American Institute of Physics.

He is currently the Principle Investigator on the European H2020 AERIALIST project investigating how the latest additive manufacturing technologies can be used to produce novel metamaterials for the control of aircraft noise.

Publications and Further Research Outputs

Peer-Reviewed Publications

Dowling L., Kennedy J., O'Shaughnessy S., Trimble D., A review of critical repeatability and reproducibility issues in powder bed fusion, Materials and Design, 186, 2020 Journal Article, 2020 DOI

Roberto Merino-Martínez, Eleonora Neri, Mirjam Snellen, John Kennedy, Dick G. Simons and Gareth J. Bennett, Multi-Approach Study of Nose Landing Gear Noise, Journal of Aircraft , 57, (3), 2020, p517 - 533 Journal Article, 2020 DOI URL

H.J.Rice J.Kennedy P.Göransson L.Dowling D.Trimble, Design of a Kelvin cell acoustic metamaterial, Journal of Sound and Vibration, 472, (115167), 2020 Journal Article, 2020 TARA - Full Text DOI

Jennings, Simon; Kennedy, John, Detection and Evaluation of Amplitude Modulation From a Wind Energy Development, Ireland, Acta Acustica united with Acustica, Volume 105, (Number 6), 2019, p1042 - 1052 Journal Article, 2019

Kennedy, J., L., Flanagan, Dowling, L., Rice, H., Trimble, D., , The influence of additive manufacturing processes on the performance of a periodic acoustic metamaterial, International Journal of Polymer Science, Volume 2019, (Article ID 7029143), 2019 Journal Article, 2019 URL TARA - Full Text

L. Flanagan, H. Rice, J. Kennedy, Sub-wavelength acoustic liner via "metamaterials", 21st Workshop of the Aeroacoustics Specialists Committee of the CEAS - New materials for applications in aeroacoustics, Rome, Italy, 2019 Oral Presentation, 2019

Faulkner Jon Paul, Cassidy Matthew, Murphy Enda, Kennedy John, Rice Henry, Validation of Acceleration and Deceleration in proximity to Junctions under CNOSSOS-EU , Irish Transport Research Network Conference , 2019, 2019 Conference Paper, 2019

John Kennedy, Lara Flanagan, Luke Dowling, Gareth J. Bennett, Henry Rice, and Daniel Trimble, The Influence of Additive Manufacturing Processes on the Performance of a Periodic Acoustic Metamaterial, International Journal of Polymer Science, 2019, 2019, p1-11 Journal Article, 2019 TARA - Full Text URL

Kennedy John, Dowling Luke, Flanagan Lara, Rice Henry, Trimble Daniel, The influence of additive manufacturing strategies on the performance of acoustic metamaterials , 9th EASN International Conference on Innovation in Aviation and Space , 2019, 2019 Conference Paper, 2019

L. Dowling, D. Heaphy, D. Trimble, J. Kennedy, Repeatability in additive manufacturing for metamaterials, 21st Workshop of the Aeroacoustics Specialists Committee of the CEAS - New materials for applications in aeroacoustics, Rome, Italy, 2019 Oral Presentation, 2019

Patrick N Okolo, Kun Zhao, John Kennedy, Gareth J Bennett, Numerical assessment of flow control capabilities of three dimensional woven wire mesh screens, European Journal of Mechanics - B/Fluids, 76, 2019, p259-271 Journal Article, 2019 URL

Kun Zhao, Patrick Okolo, Eleonora Neri, Peng Chen, John Kennedy, Gareth J. Bennett, Noise reduction technologies for aircraft landing gear-A bibliographic review, Progress in Aerospace Sciences, 112, 2019, p100589 Journal Article, 2019 URL DOI

Eleonora Neri, John Kennedy and Gareth J. Bennett, Bay Cavity Noise for Full-Scale Nose Landing Gear: a comparison between experimental and numerical results, Aerospace Science and Technology, 72, 2018, p278 - 291 Journal Article, 2018 URL DOI

Dowling, L. and Mao, H. and Flanagan, L. and Kennedy, J. and Cuenca, J. and Rice, H. and Trimble, D. and Göransson, P., A combined design-manufacturing-testing investigation of micro- To macro-scale tailoring of open poroelastic materials based on perturbed Kelvin cell micro-geometries, 2018, pp1163-1177 Conference Paper, 2018

Dowling, L., Flanagan, L., Rice, H., Trimble, D., and Kennedy, J, The use of a benchmark periodic metamaterial to inform numerical modelling and additive manufacturing approaches, ISMA 2018, (paper no 518), 2018 Conference Paper, 2018

H.J.Rice J.Kennedy and P.Göransson, Design of a kelvin cell acoustic metamaterial, ISMA 2018, Leuven, Belgium, (paper no 514), 2018 Conference Paper, 2018

Gareth J. Bennett, Eleonora Neri, John Kennedy, Noise Characterization of a Full-Scale Nose Landing Gear, AIAA Journal of Aircraft, 55, (6), 2018, p2476 - 2490 Journal Article, 2018 TARA - Full Text URL DOI

John Kennedy, Petr Eret, Gareth J. Bennett, A parametric study of airframe effects on the noise emission from installed contra-rotating open rotors, International Journal of Aeroacoustics, 17, (6-8), 2018, p624-654 Journal Article, 2018 DOI URL

Kun Zhao, Patrick Okolo, Yong Wang, John Kennedy, Gareth J. Bennett, An Experimental Characterization of the Interaction Between Two Tandem Planar Jets in a Crossflow, Journal of Fluids Engineering, 140, (11), 2018, p111106-1 - 111106-12 Journal Article, 2018 DOI URL Other

Kennedy J., Bennett G.J., A parametric study of airframe effects on installed contra rotating open rotor noise, 21st Workshop of the Aeroacoustics Specialists Committee of the CEAS - Aircraft Noise Generated from Ducted or Un-Ducted Rotors, Dublin, Ireland, 2017 Oral Presentation, 2017

Kun Zhao, Patrick N. Okolo, John Kennedy, Gareth J Bennett, 2D PIV measurement on the interaction zone between two parallel planar jets in a crossflow, AIP Advances, 7, (10), 2017, p105104 Journal Article, 2017 TARA - Full Text URL

Laurent Sanders, D.-C. Mincu, P. L. Vitagliano, M. Minervino, John Kennedy and Gareth J. Bennett, Prediction of the acoustic shielding by aircraft empennage for contra-rotating open rotors, International Journal of Aeroacoustics, 16, (7-8), 2017, p626 - 648 Journal Article, 2017 URL TARA - Full Text

Okolo Patrick N., Zhao Kun, Kennedy John, Bennett Gareth J., Numerical Modeling of Wire Screens for Flow and Noise Control , 2017, American Institute of Aeronautics and Astronautics , 2017 Conference Paper, 2017 URL

Kennedy J., Okolo P.N., Bennett G.J., A numerical and experimental investigation of the contribution of bay cavity resonances to landing gear noise, 20th Workshop of the Aeroacoustics Specialists Committee of the CEAS - Measurement Techniques and Analysis Methods for Aircraft Noise, University of Southampton, United Kingdom, 2016 Oral Presentation, 2016

Patrick N. Okolo, Kun Zhao, John Kennedy, and Gareth J. Bennett, Mesh Screen Application for Noise Reduction of Landing Gear Strut, 22nd AIAA/CEAS Aeroacoustics Conference, Lyon, France, 30 May 2016, AIAA, 2016 Conference Paper, 2016 URL DOI

Petr Eret, John Kennedy, Paolo Castellini, Francesco Amoroso, Gareth J. Bennett, Experimental observations of an installed-on-pylon contra-rotating open rotor with equal blade number in pusher and tractor configuration, International Journal of Aeroacoustics, 15, (1-2), 2016, p228 - 249 Journal Article, 2016 DOI URL TARA - Full Text

Ian Walker , John Kennedy , Susanna Martin , Henry Rice, How Might People Near National Roads Be Affected by Traffic Noise as Electric Vehicles Increase in Number? A Laboratory Study of Subjective Evaluations of Environmental Noise, PLoS ONE, 11, (3), 2016 Journal Article, 2016 DOI URL

Eleonora Neri, John Kennedy, Gareth J. Bennett, Aeroacoustic Source Separation on a Full Scale Nose Landing Gear Featuring Combinations of Low Noise Technologies, ASME 2015 Noise Control and Acoustics Division Conference at InterNoise 2015, San Francisco, CA., USA, 9-12 August 2015, ASME, 2015, ppV001T01A006; 11 pages Conference Paper, 2015 TARA - Full Text URL

Gareth J. Bennett, John Kennedy, Craig Meskell, Michael Carley, Peter Jordan, Henry Rice, Aeroacoustics research in Europe: The CEAS-ASC report on 2013 highlights, Journal of Sound and Vibration, 340, 2015, p39 - 60 Journal Article, 2015 URL DOI

Petr Eret, John Kennedy, Gareth J. Bennett, Effect of noise reducing components on nose landing gear stability for a mid-size aircraft coupled with vortex shedding and freeplay, Journal of Sound and Vibration, 354, 2015, p91 - 103 Journal Article, 2015 DOI URL

Kennedy J., Eret P., Bennett G.J., The Influence of Airframe Installation on the Broadband Component of CROR Noise, 19th CEAS-ASC Workshop and 5th Scientific Workshop of X-Noise EV, Broadband Noise of Rotors and Airframe, La Rochelle, France, , 23-25 September, 2015 Oral Presentation, 2015

Eleonora Neri, John Kennedy, Gareth J. Bennett, Characterization of Low Noise Technologies Applied to a Full Scale Fuselage Mounted Nose Landing Gear, INTER-NOISE 2015 - 44th International Congress and Exposition on Noise Control Engineering., San Francisco, CA., USA, 9-12 August 2015, edited by Maling G.,Burroughs C. , The Institute of Noise Control Engineering of the USA, Inc., 2015, ppV001T01A005; 10 pages Conference Paper, 2015 TARA - Full Text URL DOI

Pallas Marie-AgnÚs, Berengier Michel, KENNEDY John, MORGAN Phil, GASPARONI Sara, WEHR Reinhard, Noise emission levels for electric and hybrid vehicles - First results of the FOREVER project , 2014, 2014, pp10 - p Conference Paper, 2014 URL

Kennedy, J., Holt, N., Carley, M., Walker, I., The influence of the acoustic properties of motorcycle helmets on temporary hearing threshold shift in motorcyclists, Acta Acustica United with Acustica, 100, 2014, p1129 - 1138 Journal Article, 2014 URL

Kennedy, J., Carley, M., Holt, N., Walker, I., On-road and wind-tunnel measurement of motorcycle helmet noise, Journal of the Acoustical Society of America, 134, (3), 2013 Journal Article, 2013 URL DOI

Kennedy John, Breakey David E., A simple model for the frequency dependence of turbulence length scales in jets , 2013, American Institute of Aeronautics and Astronautics , 2013 Conference Paper, 2013 URL

Holt Nigel, Walker Ian, Kennedy John, Carley Michael, Motorcycle helmets and the frequency dependence of temporary hearing threshold shift , 2011, 12 , 2011, pp050001 - Conference Paper, 2011 DOI URL

Kennedy, J., Carley, M., Holt, N., Walker, I., The effects of windscreen flow on noise in motorcycle helmets, Proceedings of Meetings on Acoustics, 12, 2011 Conference Paper, 2011

Kennedy, J., Carley, M., Holt, N., Walker, I., The Sources and Effects of Noise Exposure in Motorcycling, 161st Acoustical Society of America Conference, 2011 Conference Paper, 2011

Kennedy, J., Holt, N., Carley, M., Walker, I., Spectral filtering characteristics of a Motorcycle Helmet, Proceedings of Meetings on Acoustics, 12, 2011 Conference Paper, 2011

Kennedy, J., Adetifa, O., Carley, M., Holt, N., Walker, I., Aeroacoustic sources of motorcycle helmet noise, Journal of the Acoustical Society of America, 130, (3), 2011 Journal Article, 2011

Carley Michael, Kennedy John, Walker Ian, Holt Nigel, The experimental measurement of motorcycle noise , 2011, 12 , 2011, pp040002 - Conference Paper, 2011 URL DOI

F. Kerhervé, J. Fitzpatrick, J. Kennedy, Determination of two-dimensional space-time correlations in jet flows using simultaneous PIV and LDV measurements, Experimental Thermal and Fluid Science, 34, (6), 2010, p788-797 Journal Article, 2010 TARA - Full Text DOI

Kennedy,J. & Fitzpatrick, J. , The Effect of Chevrons on the Turbulence Characteristics of Jets, paper no. 2010-4025, AIAA/CEAS Aeroacoustics, Stockholm, Sweden, June, 2010, 2010, pp1 - 19 Conference Paper, 2010

Non-Peer-Reviewed Publications

John Kennedy, Turbulence and Noise, Faculty of Engineering, University of Bristol, February, 2018, Professor Mahdi Azarpeyvand Invited Talk, 2018

Kennedy, J., Holt, N., Walker, I., The influence of sound on the safety of vulnerable road users, SWOV Institute for Road Safety Research, 2011 Invited Talk, 2011

Research Expertise

Projects

  • Title
    • AERIALIST
  • Summary
    • AERIALIST aims at the application of acoustic metamaterial technologies to modify the intensity and the directivity patterns of aircraft noise sources in order to mitigate the community noise induced by the civil aviation. AERIALIST aims to: i)Extend acoustic metamaterial theory to take into account the effect of a realistic aerodynamic flow and comply to the strict weight constraints typical of the aeronautical applications. ii) Develop advanced numerical methods to simulate acoustic metamaterial in aeronautic operating conditions and characterize the mechanical properties required to achieve the target behaviour. iii) Use state of the art additive manufacturing technologies to develop new strategies for the manufacture of acoustic meta-materials in physically useful volumes and provide a roadmap for future development to higher TRL. iv) Provide a proof of concepts through the experimental validations of the most promising designs, evaluate the technical feasibility of noise-reductions devices based on the developed technology, and identify a possible roadmap to their practical realization.
  • Funding Agency
    • EU H2020
  • Date From
    • 01/06/2017
  • Date To
    • 31/05/2020
  • Title
    • TANDEM
  • Summary
    • TANDEM (Tuneable Acoustic Noise DampEning Materials) brings together expertise from acoustics, applied mathematics, and chemistry to deliver the next generation of acoustic materials. It will focus on the development of SoundBounce - an innovative new noise-cancelling metamaterial. The smart acoustic material can be used in the automotive, aerospace, construction, and power generation industries. SoundBounce provides a cost-effective way of absorbing harmful or unwanted noise, protecting people and structures.
  • Funding Agency
    • EU H2020
  • Date From
    • 01/06/2019
  • Date To
    • 31/05/2021
  • Title
    • Advanced acoustic metamaterials for noise reduction, optimised for additive manufacturing technologies
  • Summary
    • In recent years a new class of acoustic materials with highly unusual properties has been proposed known as an acoustic metamaterial. These materials have the ability to alter the reflection, refraction or diffraction of sound in a controlled manner that is unlike any traditional or natural material. These metamaterials are often based on a complex geometric microstructure that must be precision manufactured to achieve the acoustic properties desired. Firstly this research will address the design of the material microstructure. Designs must be amenable to numerical simulations so that targeted behaviour can be achieved. The second challenge lies in successfully manufacturing the designed microstructure to the necessary precision. Finally the design loop will be closed as the physical test results are used to validate and develop the numerical simulations. This will allow an iterative design process which will expand our understanding of the physics and manufacture of these metamaterials with each iteration through the loop.
  • Funding Agency
    • Irish Research Council
  • Date From
    • 01/09/2019
  • Date To
    • 31/08/2023
  • Title
    • Noise-Adapt
  • Summary
    • In accordance with Art. 6.2 of the Environmental Noise Directive (END), the European Commission recently developed Common Noise assessment methods (CNOSSOS-EU) for road, railway, aircraft and industrial noise to be used after adoption by the Member States for the purpose of strategic noise mapping as required by Article 7 of the END. Noise-Adapt will provide a transitional needs assessment for adapting to CNOSSOS-EU in the Irish context for road, rail, air, and industry, including the administration of a standardised approach for population exposure estimation (Strategic Noise Mapping).
  • Funding Agency
    • Environmental Protection Agency
  • Date From
    • 01/2/2018
  • Date To
    • 01/06/2020
  • Title
    • WENEMOR
  • Summary
    • The WENEMOR project has been developed in response to the requirements of the European Clean Sky Joint Technology Initiative to assess the aero-acoustic noise emissions for an advanced regional open rotor aircraft configuration. The consortium consists of 7 partners including two universities (Trinity College Dublin and Università Politecnica delle Marche), a large European wind tunnel facility (Pininfarina) and several SMEs (Eurotech, Teknosud, MicrodB and Paragon S.A.) with specific competences in design and manufacture and noise measurements and data analysis. The project utilises a proposed design for an advanced regional aircraft configuration for the model geometries with realistic modern blade profiles for the propulsion system. The project has designed, manufactured and tested a 1/7th scale model of the proposed open rotor aircraft design. The model consisted of a modular design featuring interchangeable tail pieces, variable fuselage length, engine pylon rotation and elongation and was controllable for angle of attack. The test campaign consisted of aero-acoustic measurements in an open test section of a large low speed wind tunnel for a wide ranging set of configurations.
  • Funding Agency
    • EU Clean Sky
  • Date From
    • 01/09/2011
  • Date To
    • 28/02/2013
  • Title
    • FOREVER
  • Summary
    • The FOREVER project (Future OpeRational impacts of Electric Vehicles on national European Roads) addresses future vehicle technologies, specifically electric and hybrid-electric vehicles and low-noise tyres, as part of the CEDR Transnational Road Research Programme Call 2012 on Noise. The project aims primarily to provide data and information on the potential future noise impacts and noise-related safety impacts of electric vehicles on national roads, the latter considering the safety of other road users. As such, this takes a different focus from much of the previous research in these areas, which has generally focussed on the noise impacts in city (low-speed) environments and the potential safety risks posed to pedestrians.
  • Funding Agency
    • CEDR
  • Date From
    • 01/01/2013
  • Date To
    • 31/12/2014
  • Title
    • ALLEGRA
  • Summary
    • This project focuses on the design and testing of Main and Nose Landing Gear noise reduction concepts. The outputs of ALLEGRA will result in pragmatic, validated solutions which will reduce noise, emissions and improve fuel consumption. These solutions will be developed in conjunction with an EU aircraft manufacturer (Alenia) to ensure feasibility and to reduce time to implementation. During landing approach when engines are operating at low thrust the noise of the airframe contributes strongly to the overall noise signature of modern aircraft. Airframe noise is generated by airflow around components of the aircraft. The main sources of airframe noise are therefore the high drag elements such as landing gears and also the high lift devices on the wings. For larger aircraft, it is the landing gear noise that dominates. ALLEGRA will carry out conceptual design and aeroacoustic measurements in an open test section of a large low speed aeroacoustic wind tunnel, on complete reduced or full scale modular models of different configurations of main and nose landing gear.
  • Funding Agency
    • EU Clean Sky
  • Date From
    • 01/01/2013
  • Date To
    • 31/12/2014

Keywords

ACOUSTICS; Aerodynamics; Aeronautics; Air Transport Technology; Applied thermodynamics and energy; Computational Fluid Dynamics; Environmental aspects of transportation; Fluid Dynamics; Fluid Mechanics; Fluids and vibration; Manufacturing engineering; Mechanical Engineering; Noise pollution, technology; Signal processing; Sound Engineering; Transport psychology and safety; Turbomachinery; Turbulence; Vibration and Accoustic Engineering; Wind Tunnels

Recognition

Representations

Scientific Committee of the 21st Workshop of the Aeroacoustics Specialists Committee of the Council of European Aerospace Societies 2017

Scientific Committee of the 23rd Workshop of the Aeroacoustics Specialists Committee of the Council of European Aerospace Societies 2019

Scientific Committee of the 45th International JVE (Journal of Vibroengineering) Conference 2020

Memberships

Member of the Institute of Acoustics (MIOA) - The Institute of Acoustics is the UK's professional body for those working in acoustics, noise and vibration. It was formed in 1974 and is a nominated body of the Engineering Council, offering registration at Chartered and Incorporated Engineer levels. The range of interests of members embraces aspects such as aerodynamics, architectural acoustics, building acoustics, electroacoustics, engineering dynamics, noise and vibration, hearing, speech, underwater acoustics, together with a variety of environmental aspects.