Size measurement of bubbles in a cavitation tunnel by digital in-line holography

作者:Lebrun Denis*; Allano Daniel; Mees Loic; Walle Francoise; Corbin Frederic; Boucheron Romuald; Frechou Didier
来源:Applied Optics, 2011, 50(34): H1-H9.
DOI:10.1364/AO.50.0000H1

摘要

Digital in-line holography (DIH) with a divergent beam is used to measure size and concentration of cavitation bubbles (6-100 mu m) in hydrodynamic facilities. A sampling probe is directly inserted in the cavitation tunnel, and the holograms of the bubbles are recorded through a transparent test section specially designed for DIH measurements. The recording beam coming from a fiber-coupled laser diode illuminates the sample volume, and holograms are recorded by a CMOS camera. From each hologram, the sampling volume can be reconstructed slice by slice by applying a wavelet-based reconstruction method. Because of the geometry of the recording beam, a magnification ratio must be introduced for recovering the 3D location and size of each bubble. The method used for processing holograms recorded in such a configuration is presented. Then, statistical results obtained from 5000 holograms recorded under different pressures in the cavitation tunnel are compared and discussed.

  • 出版日期2011-12-1