Measurement of Flow Velocity Distribution by Molecular Velocimetry Using Laser Photothermal Effect

This paper describes the molecular velocimetry system for measuring the velocity distribution of turbulent flow using the photothermal effect. For reducing influence of environmental phase fluctution due to turbulent flow in detecting the photothermal effect, we use a CCD camera synchronization in association with double pulses of a laser diode in recording images of the differential interferometer. And the obtained images before and after pumpings are differentiated by an image processor.