3D measurement of a series of rising air bubbles using digital holography
Details
This paper presents the measurement results of air bubbles rising in a cubic cavity with digital holography. The air bubbles in water are illuminated with He-Ne laser light and the resulting interference fringes are recorded with a high-speed CMOS camera to analyze them on a digital computer based on wave optics. Full-volume digital holography is employed for the detection of bubble position in 3D space. The bubble position in depth is estimated by taking the position of bubble image where the horizontal gradient averaged in a local area on the boundary of bubble image has the maximum value along the axis of depth. The experimental results show that the present technique successfully express the motion of rising air bubbles generated from a nozzle at the bottom of the cavity.
