Detection method of a position pierced by a single-tip optical fibre probe in bubble measurement

作者：Mizushima Yuki; Saito Takayuki^*

来源：Measurement Science and Technology, 2012, 23(8): 085308.

DOI：10.1088/0957-0233/23/8/085308

• single-tip optical fibre probe
• bubble
• pre-signal
• chord length
• velocity
• simultaneous measurement

An optical fibre probe is a very useful device for practical bubble/droplet measurements of gas-liquid two-phase systems. To measure a sub-millimetre-size or micrometre-size bubble/droplet, one of the authors previously developed a single-tip optical fibre probe (S-TOP) and S-TOP micro-fabricated by a femtosecond pulse laser. The purpose of the present study was to enhance the measurement accuracy of the S-TOP. The most difficult problem to resolve in the S-TOP measurement is the detection of the position at which the S-TOP pierces a bubble/droplet. A pre-signal, which has normally been considered burdensome noise in signal analysis, can be effectively used to realize this important action. We analysed the properties of the pre-signal and discovered its hidden potential. Here we proposed a new method for effectively using the pre-signal for the practical detection of the penetrated position. We also demonstrated the effectiveness of the pre-signal method by using a bubbly flow. Finally, we conducted the uncertainty analyses of the S-TOP bubble measurement with the pre-signal method.

• 出版日期2012-8