Méthode stroboscopique à éclairs retardés pour l'étude des bulles

Optical Methods in Two-Phase Flow

“…These three general references contain all the material needed for a thorough understanding of the optical methods which can be used for temperature measurements based on a change of the refractive index (interferometry), its first derivative (schlieren) or its second derivative (shadowgraph), in a direction normal to the light beam. Degassing and nucleate pool boiling mechanisms were investigated by BEHAR andSEMERIA (1963, 1963a) by means of black-and-white and color schlierentechniques. They used the Toepler system consisting of two lenses and a horizontal linear source.…”

“…High-speed cinematography can be avoided when investigating almost periodical events by means of stroboscopic techniques (BEHAR, 1963). A stroboscope flash is triggered by the occultation of a reference light beam after a time interval which can be adjusted to any value up to 0.1 s. Bubbling of air bubbles into a liquid and coalescence of bubbles emerging from two hypodermic needles close together were visualized by BEHAR (1963).…”