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Trinity College Dublin, The University of Dublin

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John Kennedy
Research Fellow, Mechanical & Manuf. Eng

Biography

Dr. John Kennedy received his Ph.D. from Trinity College Dublin for his work 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 is also actively 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 is 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.

Publications and Further Research Outputs

Peer-Reviewed Publications

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 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 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 DOI URL

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 URL DOI

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 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., 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

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., 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

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

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
    • 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; Aeronautics; Applied thermodynamics and energy; Environmental aspects of transportation; Fluid Mechanics; Fluids and vibration; Mechanical Engineering; Noise pollution, technology; Transport psychology and safety; Turbulence; Vibration and Accoustic Engineering