Observation technique for particle orientation in concentrated suspension with flow focusing

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K06099
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Fluid engineering
• Research Institution: Tsuyama National College of Technology
• Principal Investigator: Kato Manabu 津山工業高等専門学校, 総合理工学科, 准教授 (20370017)
• Research Collaborator: TAKAHASHI Tsutomu 長岡技術科学大学, 工学部 機械創造工学専攻, 教授
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 懸濁液の流動 / 懸濁粒子の配向運動 / 流れの可視化技術 / フローフォーカシング

Outline of Final Research Achievements

In this study, we developed a technique to observe particle movement of concentrated suspension in two-dimensional flow field using flow focusing. We applied this technique to the two-dimensional Poiseuille flow field and the contraction channel flow of concentrated suspension and observed the movement of particles. In the Poiseuille flow field, we observed the orientation motion of fibrous particles which converge at the orientation angle along the streamline. In addition, their orientation motion is disturbed by the interaction with the wall surface and nearby particles. In the case of contraction channel flow, we observed that the fibrous particles show complex orientation motion at the entrance of the channel and their orientation motion influences on the flow field. From this results, we have confirmed that this technique is simple and useful method to obtain valuable data for verification of numerical models.

Free Research Field

流体工学

Academic Significance and Societal Importance of the Research Achievements

本研究は，申請者がこれまで取り組んできたフローフォーカッシングを用いたマイクロ流路測定技術の懸濁粒子測定への応用である．濃厚系懸濁粒子の観察では，粒子同士が重なり合うことで特定領域の粒子の運動を直接観察することが困難となる．本測定技術は，分散粒子に邪魔されることなく，ピンポイントで流れの中の観察したい領域の特定の粒子の撮影が可能となる．既存の手法と比較してもシンプルな測定手法であり様々な流れ場への適用が可能である．観察結果は，数値解析モデルの検証にとどまらず，流れ場による粒子の姿勢の制御に対して重要な知見が得られ，CFRPのさらなる高機能化に対して大きなインパクトを与えるものである．