2021 Fiscal Year Final Research Report
Development of phase retrieval holography using two-wavelength for measureing three-dimensional velocity and refractive index of micro-particles of phase transitions
Project/Area Number |
19K04170
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Research Category |
Grant-in-Aid for Scientific Research (C)
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Allocation Type | Multi-year Fund |
Section | 一般 |
Review Section |
Basic Section 19010:Fluid engineering-related
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Research Institution | Kyoto Institute of Technology |
Principal Investigator |
Yohsuke Tanaka 京都工芸繊維大学, 機械工学系, 准教授 (80509521)
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Project Period (FY) |
2019-04-01 – 2022-03-31
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Keywords | 位相回復ホログラフィ / 微粒子計測 |
Outline of Final Research Achievements |
Simultaneous measurement of the refractive index and 3D velocity of fine particles with a phase transition is important for understanding a wide range of phenomena (bubble dissolution, powder combustion, snowflake melting, droplet freezing). Because a change in refractive index accompanies this phase transition, it has been observed using the Schlieren and BOS methods. However, the lack of depth information makes it impossible to obtain 3D velocities. In addition, the tomographic particle image velocimetry method can measure the velocity field, but particle imaging must not change the refractive index. On the other hand, the one-wavelength phase-recovery holography developed by the applicant allows simultaneous measurement. Still, its measurement range is limited due to small refractive index changes and low depth position accuracy caused by the short-wavelength. In this study, this problem is solved by increasing the wavelength.
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Free Research Field |
流体計測
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Academic Significance and Societal Importance of the Research Achievements |
研究成果は大きく3つにわけることが出来る。1つ目は2波長位相回復ホログラフィ実施に必要なGPUを用いた高速画像処理の確立である。数十分単位の処理が数秒まで短縮されて本手法のボトルネックが解消された。2つ目は温度変化による位相変化の観測が可能となり、非接触温度計測が可能となった。最後の3つ目はマイクロチャネル内の2波長による奥行き位置精度向上と3次元速度場計測が可能であることが示せた。これらの成果から、本手法は、工学分野において粉体製造工程のセンシング利用など実運用段階に進む目途が立った。
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