In-situ photoacoustic measurement of soot profiles in laminar flames using a high repetition-rate pulsed fibre laser

Gordon S. Humphries, Robert Roy, John D. Black, Michael Lengden, Iain S. Burns

Research output: Contribution to journalArticle

Abstract

We present a photoacoustic technique for in situ sensing of particulates in reacting flows. The method is demonstrated by measuring soot distribution in laminar flat-flames. The excitation source is a high repetition-rate pulsed fibre laser. The resulting acoustic signals are measured using a uni-directional microphone and lock-in amplifier. Based on an Allan-Werle plot, the detection limit is estimated to be a soot volume fraction of 3 parts-per-billion. Fluence curves are presented, showing a plateau region similar to the behaviour typically observed for laser-induced incandescence. A dependence of the photoacoustic signal on pulse repetition rate is also demonstrated.
LanguageEnglish
Article number60
Number of pages6
JournalApplied Physics B: Lasers and Optics
Volume125
Issue number4
Early online date14 Mar 2019
DOIs
Publication statusPublished - 30 Apr 2019
Event8th International Workshop on Laser-Induced Incandescence - Evangelische Akademie, Tutzing, Germany
Duration: 10 Jun 201813 Jun 2018

Fingerprint

soot
fiber lasers
repetition
pulsed lasers
incandescence
reacting flow
pulse repetition rate
profiles
microphones
particulates
flames
plateaus
fluence
amplifiers
plots
acoustics
curves
excitation
lasers

Keywords

  • soot measurement
  • photoacoustic
  • fibre laser
  • combustion
  • laminar flames

Cite this

@article{a278a94ebd0c4431a6e3980066653b14,
title = "In-situ photoacoustic measurement of soot profiles in laminar flames using a high repetition-rate pulsed fibre laser",
abstract = "We present a photoacoustic technique for in situ sensing of particulates in reacting flows. The method is demonstrated by measuring soot distribution in laminar flat-flames. The excitation source is a high repetition-rate pulsed fibre laser. The resulting acoustic signals are measured using a uni-directional microphone and lock-in amplifier. Based on an Allan-Werle plot, the detection limit is estimated to be a soot volume fraction of 3 parts-per-billion. Fluence curves are presented, showing a plateau region similar to the behaviour typically observed for laser-induced incandescence. A dependence of the photoacoustic signal on pulse repetition rate is also demonstrated.",
keywords = "soot measurement, photoacoustic, fibre laser, combustion, laminar flames",
author = "Humphries, {Gordon S.} and Robert Roy and Black, {John D.} and Michael Lengden and Burns, {Iain S.}",
year = "2019",
month = "4",
day = "30",
doi = "10.1007/s00340-019-7169-0",
language = "English",
volume = "125",
journal = "Applied Physics B: Lasers and Optics",
issn = "0946-2171",
number = "4",

}

TY - JOUR

T1 - In-situ photoacoustic measurement of soot profiles in laminar flames using a high repetition-rate pulsed fibre laser

AU - Humphries, Gordon S.

AU - Roy, Robert

AU - Black, John D.

AU - Lengden, Michael

AU - Burns, Iain S.

PY - 2019/4/30

Y1 - 2019/4/30

N2 - We present a photoacoustic technique for in situ sensing of particulates in reacting flows. The method is demonstrated by measuring soot distribution in laminar flat-flames. The excitation source is a high repetition-rate pulsed fibre laser. The resulting acoustic signals are measured using a uni-directional microphone and lock-in amplifier. Based on an Allan-Werle plot, the detection limit is estimated to be a soot volume fraction of 3 parts-per-billion. Fluence curves are presented, showing a plateau region similar to the behaviour typically observed for laser-induced incandescence. A dependence of the photoacoustic signal on pulse repetition rate is also demonstrated.

AB - We present a photoacoustic technique for in situ sensing of particulates in reacting flows. The method is demonstrated by measuring soot distribution in laminar flat-flames. The excitation source is a high repetition-rate pulsed fibre laser. The resulting acoustic signals are measured using a uni-directional microphone and lock-in amplifier. Based on an Allan-Werle plot, the detection limit is estimated to be a soot volume fraction of 3 parts-per-billion. Fluence curves are presented, showing a plateau region similar to the behaviour typically observed for laser-induced incandescence. A dependence of the photoacoustic signal on pulse repetition rate is also demonstrated.

KW - soot measurement

KW - photoacoustic

KW - fibre laser

KW - combustion

KW - laminar flames

UR - https://link.springer.com/journal/340

U2 - 10.1007/s00340-019-7169-0

DO - 10.1007/s00340-019-7169-0

M3 - Article

VL - 125

JO - Applied Physics B: Lasers and Optics

T2 - Applied Physics B: Lasers and Optics

JF - Applied Physics B: Lasers and Optics

SN - 0946-2171

IS - 4

M1 - 60

ER -