Planar laser-induced fluorescence

About: Planar laser-induced fluorescence is a research topic. Over the lifetime, 1217 publications have been published within this topic receiving 23998 citations.

Acetone: a tracer for concentration measurements in gaseous flows by planar laser-induced fluorescence

Abstract: This paper explores the use of acetone as a suitable tracer in planar laser-induced fluorescence concentration measurements in gaseous flows. The photophysics and physical properties of acetone relevant to its use as a fluorescent marker are discussed and compared to those of alternative molecular tracers, particularly the biacetyl molecule. Finally, as a direct example, concentration images obtained in a turbulent air jet seeded alternatively with acetone and biacetyl are compared.

Measurements and modeling of acetone laser-induced fluorescence with implications for temperature-imaging diagnostics

Abstract: Recent determinations of the temperature dependence of acetone fluorescence have permitted the application of acetone planar laser-induced fluorescence imaging, which was already popular for mapping concentration, to the measurement of temperature. With a view toward developing temperature-imaging diagnostics, we present atmospheric-pressure fluorescence and absorption results acquired with excitation at eight wavelengths across the absorption feature of acetone and at temperatures from 300 to 1000 K. Modeling of the fluorescence yield of acetone is shown to be useful in explaining both these results and the variation of acetone fluorescence with pressure and composition that was observed in several studies. The model results in conjunction with the photophysics data provide guidance for the application of temperature diagnostics over a range of conditions while also suggesting useful multiparameter imaging approaches.

Planar laser-induced fluorescence imaging of flame heat release rate

Abstract: Local heat release rate represents one of the most interesting experimental observables in the study of unsteady reacting flows. The direct measure of burning or heat release rate as a field variable is not possible. Numerous experimental investigations have relied on inferring this type of information as well as flame-front topology from indirect measures that are presumed to be correlated. A recent study has brought into question many of the commonly used flame-front marker and burning-rate diagnostics. This same study found that the concentration of formyl radical offers the best possibility for measuring flame burning rate. However, primarily due to low concentrations, the fluorescence signal level from formyl is too weak to employ this diagnostic for single-pulse measurements of turbulent-reacting flows. In this paper, we describe and demonstrate a new fluorescence-based reaction-front imaging diagnostic suitable for single-shot applications. The measurement is based on taking the pixel-by-pixel product of OH and CH2O planar laser-induced fluorescence (PLIF) images to yield an image closely related to a reaction rate. The spectroscopic and collisional processes affecting the measured signals are discussed, and the foundation of the diagnostic, as based on laminar and unsteady flame calculations, is presented. We report the results of applying this diagnostic to the study of a laminar premixed flame subject to an interaction with an isolated line-vortex pair.