Rodriguez Garcia, Paul (2016) Aircraft turbine combustion noise processing. University of Southampton, Doctoral Thesis, 223pp.
Abstract
Appraisal of the noise produced at the combustion stage in a jet engine is becoming more important, as fan and jet noise have been significantly reduced over many years. Therefore, combustion noise is contributing more to overall noise, especially at low jet velocities. Environmental regulations stipulate that gas emissions from a jet engine should be reduced. Thus, new techniques have been introduced in their operation, especially concerning the combustion process. Accordingly, there is a need for improved processing methods in order to extract combustion noise from other sources in new build engines.
A novel processing technique to extract turbofan engine combustion noise called 3S-Array is presented. It has been developed using a multiple coherence technique with data acquired in the in-duct and external sound fields of a jet engine. In-duct sensors are located in the combustion chamber and in the nozzle of the engine, and external data is acquired using an array of microphones. A beamformed signal focused on the nozzle of the engine is generated with the data from the external array. Jet noise and in influences of the room on the array output are reduced using this focusing technique, which is referred to as Focused Beamformed Output (FBO).
Results show that using this new 3S-Array technique with two of the in-duct sensors and the focused beamformed signal as the third one, provides a better estimator of combustion noise than the 3-signal coherence technique alone, or the Coherence-Output Power Spectra (COP), both of which are reported in the literature as methods for the extraction of combustion noise from the radiated noise spectrum.
More information
Identifiers
Catalogue record
Export record
Contributors
University divisions
- Faculties (pre 2011 reorg) > Faculty of Engineering Science & Maths (pre 2011 reorg) > Institute of Sound & Vibration Research (pre 2011 reorg)
Current Faculties > Faculty of Engineering and Physical Sciences > School of Engineering > Institute of Sound and Vibration Research > Institute of Sound & Vibration Research (pre 2011 reorg)
Institute of Sound and Vibration Research > Institute of Sound & Vibration Research (pre 2011 reorg) - Faculties (pre 2018 reorg) > Faculty of Engineering and the Environment (pre 2018 reorg) > Inst. Sound & Vibration Research (pre 2018 reorg) > Acoustics Group (pre 2018 reorg)
Current Faculties > Faculty of Engineering and Physical Sciences > School of Engineering > Institute of Sound and Vibration Research > Inst. Sound & Vibration Research (pre 2018 reorg) > Acoustics Group (pre 2018 reorg)
Institute of Sound and Vibration Research > Inst. Sound & Vibration Research (pre 2018 reorg) > Acoustics Group (pre 2018 reorg) - Faculties (pre 2018 reorg) > Faculty of Engineering and the Environment (pre 2018 reorg) > Education Hub (pre 2018 reorg)
Download statistics
Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.