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Newsletter  2016.2  Index

Theme : "The Conference of Fluid Engineering Division"

  1. Preface
  2. Fluids Engineering supporting Artificial Heart
    Takashi YAMANE (Kobe University)
  3. Foam measurement via a single-tip optical fiber probe with surface treatment
    Ayumi NIHEI, Takayuki SAITO (Shizuoka University)
  4. Visualization of a process of ultrasonic particle flocculation depending on dissolved gas components in water
    Sayuri YANAI, Hiroya MURAMATSU, Yuki MIZUSHIMA, Takayuki SAITO (Shizuoka University)
  5. Research for Cerebral Aneurysm Recanalization After Coil Embolization Using CFD
    Soichiro FUJIMURA (Tokyo University of Science)
  6. A Water Bed, Yasutaka
    Naoya UENE (National Institute of Technology, Yonago College)
  7. Music Awa ~Music hour~
    Shuhei HATTORI, Ikuma EMORI (National Institute of Advanced Industrial Science and Technology )


Foam measurement via a single-tip optical fiber probe with surface treatment

Shizuoka University




Foam is encountered in many industrial fields, and influences safety and efficiency of a plant such as floatation and wastewater treatment. Conventional foam measurement techniques have hard limitations on their practical use in the real plants. For instance, a transparent vessel is required to visualize foam, or many electrodes are required to estimate average diameter of foam cells. In the present study, we propose a new foam measurement technique using a single tip optical fiber probe (S-TOP). The S-TOP is one of the optical fiber probes uniquely developed in our laboratory. Its optical devices are compact and smart, and it has great heat-resistance and tolerability; hence the S-TOP and its system are appropriate for practical purposes. In addition, the S-TOP possesses satisfactory performance to measure tiny foam cells; however its optical signals are very complex in the foam measurement. The authors have developed a new 3D ray tracing simulation to analyze the optical probing signals. Based on the computational results, we needed to find a falling signal in order to detect the contact of cell’s film and the S-TOP. Furthermore, we carried out two kinds of experiments; the one was an experiment of two thin soap films, and the other was an experiment of dense foam. A problem that foam cells were broken by touching the S-TOP arose. In these experiments, the surface of the S-TOP was changed to be hydrophilic by the surface treatment in order to prevent the foam burst. We obtained a result that the average chord length through the S-TOP measurement is 8.89% less than the average equivalent diameter through the visualization.

Key words

foam, measurement, chord length, single tip optical fiber probe, ray tracing simulation


Fig. 1 Optics of the S-TOP.

Fig. 2 Experimental setup.

Fig. 3 Micrograph of the S-TOP.

Fig. 4 Output signal of the piercing a film by the surface treated S-TOP.

Fig. 5 Output signal of the foam measurement.

Last update: 2.16.2016