# Fluid Mechanics and Acoustics Laboratory - UMR 5509

LMFA - UMR 5509
Laboratoire de Mécanique des Fluides et d’Acoustique
Lyon
France

## PLIF - Planar Laser-Induced Fluorescence

This non-intrusive technique allows to measure quantitatively, locally and instantaneously some characteristic quantities about reactive (or not) flows, such as the temperature, the velocity, the pressure or, in a mix case, the species concentration.

The flow to study is lit by a laser sheet which wavelength matches the absorption peak of the fluorescent specie used to mark the flow or naturally present in it. It leads to an inelastic emission at a wavelength said superior fluorescent to the illumination wavelength. This emission is related to a fluoresced intensity proportional (for given conditions) to the concentration of fluorescent molecules inside the elementary volume of measurement.

It is recorded through an optical filter by a CCD camera, intensified or not. A calibration prior to the measurement will allow to recover the absolute quantities that we wish to measure.

Fluctuating field of concentration
Thesis J.M. Lenoir

Measurements tools:
- Several double cavity pulsed Nd:Yag lasers (see PIV section)
- Several double frames CCD cameras (see PIV section)
- A double cavity pulsed Nd:YLF laser (see TR-PIV section)
- Several CMOS fast cameras (see TR-PIV section)