Cristin-resultat-ID: 1035224
Sist endret: 31. januar 2014, 12:54
NVI-rapporteringsår: 2013
Resultat
Vitenskapelig artikkel
2013

Influence of long pulse duration on time-resolved laser-induced incandescence

Bidragsytere:
  • Mario Ditaranto
  • Christoph Meraner
  • Nils Erland Leinebø Haugen og
  • Inge Saanum

Tidsskrift

Applied physics B
ISSN 0946-2171
e-ISSN 1432-0649
NVI-nivå 1

Om resultatet

Vitenskapelig artikkel
Publiseringsår: 2013
Publisert online: 2013
Trykket: 2013
Volum: 112
Hefte: 3
Sider: 359 - 367

Importkilder

Isi-ID: 000325099100007

Beskrivelse Beskrivelse

Tittel

Influence of long pulse duration on time-resolved laser-induced incandescence

Sammendrag

Time-resolved laser-induced incandescence (LII) signal of soot in an ethylene laminar diffusion flame was measured with varying laser pulse durations in the range 50–600 ns. This study presents original results since the majority of LII studies reported are based on 7–10-ns pulse duration. The LII signal from soot is a combination of heating and cooling processes of different time scales, and the influence of the pulse duration is therefore particularly relevant. The most striking finding is that when the pulse durations is longer than approximately 100 ns, the time-resolved LII signal reveals a rebound of the LII signal during its slow decaying part. This feature occurs preferably at high fluence and is unexpected as none of the physical and chemical processes known to control LII signal behaviour, and their models suggest such an effect. The phenomenon occurs with both top hat and near Gaussian temporal laser shapes. Inspection of the time-resolved emission spectra shows no indication of a laser-induced fluorescence effect, although gas-phase PAH generated during the laser heating of soot particles cannot be rejected. Other hypotheses are that the mechanism responsible for that behaviour is linked to a slow rate change of the soot morphological characteristics or to the generation of new particles during the long-duration laser excitation. Finally, experiments show that soot volume fraction measured by integrating the temporal LII signal is not affected by the pulse duration in any regions of the flame, implying that the LII method is applicable with long pulse duration lasers. © Springer-Verlag Berlin Heidelberg 2013

Bidragsytere

Mario Ditaranto

  • Tilknyttet:
    Forfatter
    ved Termisk energi ved SINTEF Energi AS

christoph meraner

Bidragsyterens navn vises på dette resultatet som Christoph Meraner
  • Tilknyttet:
    Forfatter

Nils Erland L Haugen

Bidragsyterens navn vises på dette resultatet som Nils Erland Leinebø Haugen
  • Tilknyttet:
    Forfatter
    ved Termisk energi ved SINTEF Energi AS

Inge Saanum

  • Tilknyttet:
    Forfatter
    ved Termisk energi ved SINTEF Energi AS
1 - 4 av 4