2020 Fiscal Year Annual Research Report
Wagging the tail: Elasticity and flexible filaments in microscopic flows
| Project/Area Number |
18K03958
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| Research Institution | Okinawa Institute of Science and Technology Graduate University |
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Principal Investigator |
HAWARD Simon 沖縄科学技術大学院大学, マイクロ・バイオ・ナノ流体ユニット, 研究員 (20812986)
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| Project Period (FY) |
2018-04-01 – 2021-03-31
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| Keywords | microfluidics / viscoelasticity / extensional flow / flow instability |
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| Outline of Annual Research Achievements |
In this project we are studying viscoelastic flows around microfluidic cylinders. Following from a successful FY2019, in FY2020 we have focused on two main research topics: (1)The behavior of viscoelastic fluids flowing past two microfluidic cylinders positioned transversely to the flow direction. The parametric study involved varying the spacing between the two cylinders and also the elasticity of the flow. Different regimes of behaviour were discovered due to a combination of steady bifurcations, resulting in the selection of different flow paths around the cylinders. The results are relevant to understanding viscoelastic flows through porous media in industrial and biological settings.
(2)The effects of the spring constant of a flexible cantilevered cylinder on the viscoelastic fluid-structure interactions. Microfluidic flexible cylinders have been fabricated with a range of radii, thus providing a range of spring constants, hence natural frequencies. The devices are being tested by tracking the deflection of the cylinders in a flowing viscoelastic fluid over a range of elasticity, encompassing steady and time-dependent flows. The work is providing interesting and new results, showing oscillations of the cylinders at high elasticity that can be either 1D or 2D, depending on the cylinder radius.
We have also begun to examine viscoelastic flows through ordered and disordered arrays of cylinders, which show strong variations in the nature of flow fluctuations depending on the type of array (staggered, aligned, ordered, disordered, etc). This work is also in progress.
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