Laser Diagnostics in Reacting Flows
(2023)- Abstract
- Burst-mode laser systems have widely been employed in diagnostics for both reactive and non-reactive flows. Unlike the continuous pulse lasers, burst-mode lasers generate pulses in bursts lasting up to 100 ms, capable to deliver high energies up to Joules per pulse. This high energy fluency is optimal for effective wavelength conversion and tuning, enabling simultaneous measurements of various species, temperature, and velocity.
In the present thesis, the burst laser system has been employed to probe intermediate combustion species within a jet burner, aiming for an accurate model validation under turbulent conditions. For the first time, to the best of the author's recognition, we show an application of fuel tracer Planar... (More) - Burst-mode laser systems have widely been employed in diagnostics for both reactive and non-reactive flows. Unlike the continuous pulse lasers, burst-mode lasers generate pulses in bursts lasting up to 100 ms, capable to deliver high energies up to Joules per pulse. This high energy fluency is optimal for effective wavelength conversion and tuning, enabling simultaneous measurements of various species, temperature, and velocity.
In the present thesis, the burst laser system has been employed to probe intermediate combustion species within a jet burner, aiming for an accurate model validation under turbulent conditions. For the first time, to the best of the author's recognition, we show an application of fuel tracer Planar Laser-Induced Fluorescence (PLIF) imaging with a remarkable 0.2 CAD temporal resolution inside an Internal Combustion Engine (ICE)'s combustion chamber. Additionally, the movement and distribution of the ground state hydroxyl radicals (OH) in plasma discharges within a gliding arc were adequately observed and analyzed. This was achieved through the built of a bespoke tunable seeded OPO system, designed to gain access into wavelengths beyond the fundamental range, such as the 284 nm wavelength for OH studies. The challenge of in-depth detection during the $2D$ PLIF imaging of OH in the gliding arc necessitated the introduction of the FRAME technique. This method, which was performed with a 10 Hz Nd:YAG laser, provided deeper $3D$ insights into the transient plasma discharge behaviour.
Furthermore, this thesis focuses on the challenges encountered while operating such an advanced, state-of-the-art system. It highlights diverse issues ranging from complicated alignment procedures, energy optimization processes, to the advanced triggering schemes. The latter becomes relevant, especially when working with high-speed cameras, intensifiers, engines, and high-voltage plasma generators. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/1730b0a0-625d-40de-8100-73ee63fb86d9
- author
- Stamatoglou, Panagiota LU
- supervisor
-
- Mattias Richter LU
- Marcus Aldén LU
- opponent
-
- Dr. Magnotti, Gaetano, KAUST, Kingdom of Saudi Arabia.
- organization
- publishing date
- 2023-10-23
- type
- Thesis
- publication status
- published
- subject
- keywords
- planar laser-induced fluorescence (PLIF), gliding arc (GA) discharge, Plasma Discharges, Turbulence, Combustion Engines, Spectroscopy, high-speed camera (HSC), Burst System, OH-LIF, optical parametric oscillator (OPO), Fysicumarkivet A:2023:Stamatoglou
- pages
- 203 pages
- publisher
- Department of Physics, Lund University
- defense location
- Lecture Hall Rydbergsalen, Department of Physics, Professorsgatan 1, Faculty of Engineering LTH, Lund University, Lund.
- defense date
- 2023-11-16 09:15:00
- ISSN
- 1102-8718
- ISBN
- 978-91-8039-821-3
- 978-91-8039-822-0
- project
- Laserassisterad höghastighetsavbildning
- language
- English
- LU publication?
- yes
- id
- 1730b0a0-625d-40de-8100-73ee63fb86d9
- date added to LUP
- 2023-10-23 09:50:43
- date last changed
- 2024-02-02 10:27:58
@phdthesis{1730b0a0-625d-40de-8100-73ee63fb86d9,
abstract = {{Burst-mode laser systems have widely been employed in diagnostics for both reactive and non-reactive flows. Unlike the continuous pulse lasers, burst-mode lasers generate pulses in bursts lasting up to 100 ms, capable to deliver high energies up to Joules per pulse. This high energy fluency is optimal for effective wavelength conversion and tuning, enabling simultaneous measurements of various species, temperature, and velocity.<br/>In the present thesis, the burst laser system has been employed to probe intermediate combustion species within a jet burner, aiming for an accurate model validation under turbulent conditions. For the first time, to the best of the author's recognition, we show an application of fuel tracer Planar Laser-Induced Fluorescence (PLIF) imaging with a remarkable 0.2 CAD temporal resolution inside an Internal Combustion Engine (ICE)'s combustion chamber. Additionally, the movement and distribution of the ground state hydroxyl radicals (OH) in plasma discharges within a gliding arc were adequately observed and analyzed. This was achieved through the built of a bespoke tunable seeded OPO system, designed to gain access into wavelengths beyond the fundamental range, such as the 284 nm wavelength for OH studies. The challenge of in-depth detection during the $2D$ PLIF imaging of OH in the gliding arc necessitated the introduction of the FRAME technique. This method, which was performed with a 10 Hz Nd:YAG laser, provided deeper $3D$ insights into the transient plasma discharge behaviour.<br/>Furthermore, this thesis focuses on the challenges encountered while operating such an advanced, state-of-the-art system. It highlights diverse issues ranging from complicated alignment procedures, energy optimization processes, to the advanced triggering schemes. The latter becomes relevant, especially when working with high-speed cameras, intensifiers, engines, and high-voltage plasma generators.}},
author = {{Stamatoglou, Panagiota}},
isbn = {{978-91-8039-821-3}},
issn = {{1102-8718}},
keywords = {{planar laser-induced fluorescence (PLIF); gliding arc (GA) discharge; Plasma Discharges; Turbulence; Combustion Engines; Spectroscopy; high-speed camera (HSC); Burst System; OH-LIF; optical parametric oscillator (OPO); Fysicumarkivet A:2023:Stamatoglou}},
language = {{eng}},
month = {{10}},
publisher = {{Department of Physics, Lund University}},
school = {{Lund University}},
title = {{Laser Diagnostics in Reacting Flows}},
year = {{2023}},
}