Development of tunable diode laser spectroscopy sensor systems for line-of-sight measurement of water vapour in aero engine exhaust plumes

James Bain, John Black, Michael Lengden, Walter Johnstone

Research output: Contribution to conferenceSpeech

Abstract

Measurements of exhaust plume water vapour concentration and temperature are acquired on the Rolls-Royce Environmentally Friendly Engine (EFE) demonstrator. Line-of-sight tunable diode laser spectroscopy (TDLS) measurements yield the absorption spectra of water vapour downstream of the engine exhaust, using direct measurement and wavelength modulation spectroscopy (WMS) to recover absorption from both the high temperature plume and the surrounding ambient airflow. The annular array of 24 exhaust nozzles has been identified as a suitable platform for future tests to create tomographic maps of exhaust products.
Initial field trials were performed to evaluate optical system performance in the harsh environments experienced downstream of aero engine exhaust nozzles. Beam steering in the exhaust plume and highly vibrating mounting hardware provide the greatest challenges to achieving adequate signal-to-noise ratios. The optical layout of the test bed installation and the overall experimental system is described. The recovered spectra are used to fit a theoretical signal, created using an assumed temperature and concentration distribution based on anticipated plume dimensions, showing plume temperatures up to 850 K. The presence of water vapour hot lines is also confirmed using high sensitivity WMS techniques and these are compared to lines predicted by the HITRAN 08 spectral database
Original languageEnglish
Publication statusPublished - 5 Sep 2012
EventPHOTON12 -
Duration: 31 Mar 2011 → …

Other

OtherPHOTON12
Period31/03/11 → …

Fingerprint

laser spectroscopy
line of sight
plumes
water vapor
engines
diodes
exhaust nozzles
sensors
modulation
beam steering
test stands
mounting
wavelengths
layouts
spectroscopy
installing
hardware
temperature distribution
signal to noise ratios
platforms

Keywords

  • photon12
  • durham
  • tunable diode laser spectroscopy
  • sensor systems
  • line-of-sight measurement
  • aero engine exhaust plumes
  • water vapour

Cite this

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title = "Development of tunable diode laser spectroscopy sensor systems for line-of-sight measurement of water vapour in aero engine exhaust plumes",
abstract = "Measurements of exhaust plume water vapour concentration and temperature are acquired on the Rolls-Royce Environmentally Friendly Engine (EFE) demonstrator. Line-of-sight tunable diode laser spectroscopy (TDLS) measurements yield the absorption spectra of water vapour downstream of the engine exhaust, using direct measurement and wavelength modulation spectroscopy (WMS) to recover absorption from both the high temperature plume and the surrounding ambient airflow. The annular array of 24 exhaust nozzles has been identified as a suitable platform for future tests to create tomographic maps of exhaust products. Initial field trials were performed to evaluate optical system performance in the harsh environments experienced downstream of aero engine exhaust nozzles. Beam steering in the exhaust plume and highly vibrating mounting hardware provide the greatest challenges to achieving adequate signal-to-noise ratios. The optical layout of the test bed installation and the overall experimental system is described. The recovered spectra are used to fit a theoretical signal, created using an assumed temperature and concentration distribution based on anticipated plume dimensions, showing plume temperatures up to 850 K. The presence of water vapour hot lines is also confirmed using high sensitivity WMS techniques and these are compared to lines predicted by the HITRAN 08 spectral database",
keywords = "photon12, durham, tunable diode laser spectroscopy, sensor systems, line-of-sight measurement, aero engine exhaust plumes, water vapour",
author = "James Bain and John Black and Michael Lengden and Walter Johnstone",
year = "2012",
month = "9",
day = "5",
language = "English",
note = "PHOTON12 ; Conference date: 31-03-2011",

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TY - CONF

T1 - Development of tunable diode laser spectroscopy sensor systems for line-of-sight measurement of water vapour in aero engine exhaust plumes

AU - Bain, James

AU - Black, John

AU - Lengden, Michael

AU - Johnstone, Walter

PY - 2012/9/5

Y1 - 2012/9/5

N2 - Measurements of exhaust plume water vapour concentration and temperature are acquired on the Rolls-Royce Environmentally Friendly Engine (EFE) demonstrator. Line-of-sight tunable diode laser spectroscopy (TDLS) measurements yield the absorption spectra of water vapour downstream of the engine exhaust, using direct measurement and wavelength modulation spectroscopy (WMS) to recover absorption from both the high temperature plume and the surrounding ambient airflow. The annular array of 24 exhaust nozzles has been identified as a suitable platform for future tests to create tomographic maps of exhaust products. Initial field trials were performed to evaluate optical system performance in the harsh environments experienced downstream of aero engine exhaust nozzles. Beam steering in the exhaust plume and highly vibrating mounting hardware provide the greatest challenges to achieving adequate signal-to-noise ratios. The optical layout of the test bed installation and the overall experimental system is described. The recovered spectra are used to fit a theoretical signal, created using an assumed temperature and concentration distribution based on anticipated plume dimensions, showing plume temperatures up to 850 K. The presence of water vapour hot lines is also confirmed using high sensitivity WMS techniques and these are compared to lines predicted by the HITRAN 08 spectral database

AB - Measurements of exhaust plume water vapour concentration and temperature are acquired on the Rolls-Royce Environmentally Friendly Engine (EFE) demonstrator. Line-of-sight tunable diode laser spectroscopy (TDLS) measurements yield the absorption spectra of water vapour downstream of the engine exhaust, using direct measurement and wavelength modulation spectroscopy (WMS) to recover absorption from both the high temperature plume and the surrounding ambient airflow. The annular array of 24 exhaust nozzles has been identified as a suitable platform for future tests to create tomographic maps of exhaust products. Initial field trials were performed to evaluate optical system performance in the harsh environments experienced downstream of aero engine exhaust nozzles. Beam steering in the exhaust plume and highly vibrating mounting hardware provide the greatest challenges to achieving adequate signal-to-noise ratios. The optical layout of the test bed installation and the overall experimental system is described. The recovered spectra are used to fit a theoretical signal, created using an assumed temperature and concentration distribution based on anticipated plume dimensions, showing plume temperatures up to 850 K. The presence of water vapour hot lines is also confirmed using high sensitivity WMS techniques and these are compared to lines predicted by the HITRAN 08 spectral database

KW - photon12

KW - durham

KW - tunable diode laser spectroscopy

KW - sensor systems

KW - line-of-sight measurement

KW - aero engine exhaust plumes

KW - water vapour

UR - http://www.photon.org.uk/home

M3 - Speech

ER -