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Estimating the effective viscosity of bubble suspensions in oscillatory shear flows by means of ultrasonic spinning rheometry
| Title: | Estimating the effective viscosity of bubble suspensions in oscillatory shear flows by means of ultrasonic spinning rheometry |
| Authors: | Tasaka, Y. Browse this author →KAKEN DB | | Kimura, T. Browse this author →KAKEN DB | | Murai, Y. Browse this author |
| Issue Date: | Jan-2015 |
| Publisher: | Springer |
| Journal Title: | Experiments in fluids |
| Volume: | 56 |
| Issue: | 1 |
| Start Page: | 1867 |
| Publisher DOI: | 10.1007/s00348-014-1867-5 |
| Abstract: | We have proposed a novel methodology using ultrasonic velocity profiling to estimate the effective viscosity of bubble suspensions that are accompanied by non-equilibrium bubble deformations in periodic shear flows. The methodology was termed "ultrasonic spinning rheometry" and validated on measurement of the effective viscosity of particle suspensions that has a semi-empirical formula giving good estimation of the actual viscosity. The results indicated that the proposed technique is valid for particle volume fractions below 3.0 %. Applying this to bubble suspensions suggested that the effective value of temporal variations in the capillary number, Carms, is an important indicator to distinguish regimes in estimating the effective viscosity: Unsteady flows having larger Carms number than the critical capillary number for the deformation of bubbles are categorized into Regime 2 that includes both highly unsteady conditions and large steady deformation of bubbles. |
| Rights: | The final publication is available at Springer via http://dx.doi.org/10.1007/s00348-014-1867-5. |
| Type: | article (author version) |
| URI: | http://hdl.handle.net/2115/60405 |
| Appears in Collections: | 工学院・工学研究院 (Graduate School of Engineering / Faculty of Engineering) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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Submitter: 田坂 裕司
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