An application of high-speed microholography: the mertology of fogs

Abstract

Holograms of fogs produced in a high-altitude propeller test cell were recorded in the following condition: Pressure 0,5 atm; temperature 0 °C; velocity of the fog 100 m/s. The droplet diameters ranged between 5 and 50 μm. Reconstructed images were enlarged X 1000 and visualized with the help of a TV-system. Individual measurements on the particules porvided the local concentration and diameter repartition. Moreover, the use of double-pulse holography gives the three components of the speed vector for each particle. The optical arrangement and apparatus are described. The influence of experimental parameters upon the precision of measures is discussed.