DOI: 10.1615/ICHMT.1997.IntSymLiqTwoPhaseFlowTranspPhen
ISBN Print: 1-56700-162-9
LASER GRATING VELOCIMETRY FOR LIQUID-LIQUID SYSTEMS
SINOPSIS
The Laser Grating Technique (LGV) was developed for the measurement of large particles velocity and size in flow. The technique uses a single laser beam passing through a single or a double rotating optical grating. These allow a sub-division of the beam into a net of sub-beams. An interaction with a particle in motion generates a set of refracted or reflected light beams that are turned into a burst type electronic signal with the use of a simple photodetector. The frequency of the detected signal, required for the evaluation of the local velocity, is determined by Fast Fourier Transform analysis. The rotation of two disk gratings at different speeds allows after electronic filtration, the detection of two directional velocity, using a single beam. The size of the particle may be calculated by the detected passage time of the particle through the main beam.