Measurement of tiny droplets using a newly developed optical fibre probe micro-fabricated by a femtosecond pulse laser

Abstract

Optical fibre probing is widely applied to measurement in gas-liquid two-phase flows.We already developed and reported a Four-Tip Optical fibre Probe (F-TOP) for millimetre-size bubbles/droplets, and a Single-Tip Optical fibre Probe (S-TOP equipped with a wedge-shaped tip) for sub-millimetre-size bubbles/droplets.However, it is difficult to measure micrometre-size bubbles/droplets by S-TOP.The main purpose of the present study was to develop a new type of optical fibre probe micro-fabricated by a femtosecond pulse laser (fs-ProbeFs-TOP).First, we confirmed the performance of the new probe by examining millimetre-and sub-millimetre-size droplets; the results by fs-ProbeFs-TOP were compared with those obtained from the visualization of the droplets by high-speed video camera, and showed satisfactory agreement.In addition, we demonstrated the measurement of velocities and chord lengths of micrometre-size droplets (about 50 μm in diameter) using the fs-ProbeFs-書式変更: 間隔 段落前 : 0 pt, 段落後 : 0 pt