| Project/Area Number |
21J10517
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| Research Category |
Grant-in-Aid for JSPS Fellows
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| Allocation Type | Single-year Grants |
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| Section | 国内 |
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| Review Section |
Basic Section 19010:Fluid engineering-related
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| Research Institution | Okinawa Institute of Science and Technology Graduate University |
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Principal Investigator |
Chan San To 沖縄科学技術大学院大学, 科学技術研究科, 特別研究員(DC2)
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| Project Period (FY) |
2021-04-28 – 2023-03-31
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| Project Status |
Completed (Fiscal Year 2022)
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| Budget Amount *help |
¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 2022: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 2021: ¥800,000 (Direct Cost: ¥800,000)
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| Keywords | Viscoelasticity / Edge Fracture / Liquid Metal / Galinstan / Liquid Bridges / Elastoviscoplasticity / Rheology / 流体工学 / レオロジー |
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| Outline of Research at the Start |
Dispensing of viscoelastic fluids is common in applications like electronic packaging, food engineering and additive manufacturing. However, viscoelasticity leads to problems like slow liquid bridge breakup, stringiness and satellite droplets generation. In my research, I show that torsion can break short, capillary stable liquid bridges quickly. My study is the first attempt to take advantage of edge fracture (an often undesired viscoelastic flow instability) to benefit practical applications, which will potentially lead to new and improved fluid dispensing protocols.
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| Outline of Annual Research Achievements |
Over the past two years, I've focused on exploring the behaviors of viscoelastic fluids, especially their formation into stable liquid bridges due to surface tension. Through high-speed imaging and numerical simulations, I have found that torsion can destabilize these bridges through a mechanism called edge fracture. This finding may enhance the efficiency of fluid dispensing in various industries, such as electronic packaging, food engineering, and additive manufacturing. This discovery extends beyond simple viscoelastic fluids to more complex thixotropic elastoviscoplastic (TEVP) fluids, showing its potential to be incorporated into improved dispensing protocols for real-world industrial fluids.
I have also delved into the issue of edge fracture as an undesirable phenomenon in rheological measurements. I demonstrated that sealing the fluid's free surface with Galinstan, a nontoxic liquid metal, can delay edge fracture. This simple yet effective solution extends the measurable shear rate range, providing a valuable tool for the broader rheological study of complex fluids.
Overall, my research contributes to a deeper understanding of viscoelastic fluid behavior and offers practical solutions to the challenges faced in their manipulation and measurement.
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| Research Progress Status |
令和4年度が最終年度であるため、記入しない。
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| Strategy for Future Research Activity |
令和4年度が最終年度であるため、記入しない。
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