Sökning: "Laser excitation"
Visar resultat 6 - 10 av 117 avhandlingar innehållade orden Laser excitation.
6. Application of Laser Techniques for Combustion Studies
Sammanfattning : The aim for this work has been to increase the applicability of laser spectroscopy techniques for studies of combustion processes, both what regards in-flame experiments, exhaust-gas analysis and remote sensing of the atmosphere. Raman spectroscopy has been used for analysis of exhaust gases from flames, model fires of wood and for inflame measurements. LÄS MER
7. Development of Multi-Dimensional Laser Techniques for In-situ Combustion Diagnostics
Sammanfattning : Multi-dimensional, laser-based measurements of quantities important for obtaining a better understanding of combustion processes, particularly of temperature and of species distributions, were performed using laser-induced fluorescence (LIF). The main purpose of the temperature experiments was to investigate the potential of employing a two-line atomic fluorescence technique (TLAF), using indium as the tracer species, in sooting environments such as in diesel engines. LÄS MER
8. Laser Diagnostics in Combustion - Elastic Scattering and Picosecond Laser-Induced Fluorescence
Sammanfattning : Elastic scattering and the Lorenz-Mie (LM) theory in particular is used for the characterization of sub-micron- and micron-sized droplets of organic fuels in sprays and aerosols. Calculations on the Lorenz- Mie theory show that backward-sideward scattered visible radiation can be used for unambiguous detection of ensembles of homogeneous droplets of organic substances with diameters around 1 micrometer (size parameter between 2 and 6). LÄS MER
9. Sensitivity-Enhanced Raman Spectroscopy and High-Speed Fluorescence for In Situ Gas-Phase Diagnostics
Sammanfattning : In this work, combustion and thermal decomposition processes were studied employing laser-based diagnostic techniques, and the techniques were improved and demonstrated to achieve enhanced detection sensitivity. Raman spectroscopy was employed to study flames under elevated and atmospheric pressures with various fuels, such as methane, hydrogen-enriched methane, DME, ethylene, and ammonia. LÄS MER
10. Laser-based diagnostics for investigating soot formation in combustion processes
Sammanfattning : In this work, laser-based diagnostic techniques were developed and applied to investigate soot formation in small-scale laboratory burners as well as in practical combustion devices. Quantitative 2D laser-induced incandescence (LII) measurements often use a cylindrical lens to shape the beam and illuminate the planar region of interest. LÄS MER
