| 研究課題/領域番号 |
20K04192
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| 研究機関 | 京都大学 |
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研究代表者 |
ブカン アントニー 京都大学, 工学研究科, 特定准教授 (30756838)
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| 研究期間 (年度) |
2020-04-01 – 2023-03-31
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| キーワード | nano-abrasive blasting / super-fine finishing / particle agglomerates / electro-acoustic system / powder distribution / grain normalization |
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| 研究実績の概要 |
In this first phase of research, the behavior of nano-particle agglomerates was investigated.
Disaggregation of agglomerates could be simulated by smoothed particle hydrodynamics, under conditions of high shear stress imparted by intense pressure waves and impact under high velocity blasting. The tensile stress applied by electric fields was found to be relatively less effective.
Experimental verification was conducted using a small reactor supplied with N2 gas (for desiccation of agglomerates), equipped with an ultrasonic acoustic lensing system and electrode plates. TiO2 and Al2O3 nano-particles (nominal size 23-42 nm, agglomerate size 1.0-500 um) were found to readily disaggregate to a more normalized cluster size between 1.0-10 um under 26kHz/100W ultrasonic stimulation.
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| 現在までの達成度 (区分) |
現在までの達成度 (区分)
2: おおむね順調に進展している
理由
In accordance with the implementation plan (phase 1), the simulation of electro-acoustic stimulation of nano-particle aggregates by smoothed particle hydrodynamic method was carried out, allowing the identification of shear stress as the main drivers for particle disaggregation rather than tensile stress.
The implementation of an experimental reactor vessel to confirm the simulation results could also be carried out completely. Particle disaggregation was readily observed and observations of the resulting powders showed that the distribution curve of grain size was significantly narrowed, in line with expectations stated in the original research plan.
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| 今後の研究の推進方策 |
In accordance with the implementation plan (phase 2), the next step consists of designing a system for homogeneous mixing of abrasive particles within a carrier gas.
A preliminary mixing tank geometry has been proposed that allows for input of N2 gas, feeding of non-processed powder, and application of ultrasonic stimulation.
Simulations will be carried out first to confirm that both disaggregation and mixing can be achieved within the same vessel, with the geometric parameters of the tank being adjusted to achieve optimum effect on both accounts.
The next step will consist of manufacturing the mixing tank together with a Venturi effect blasting nozzle. High speed camera observations will be carried out to assess the size and homogeneity of particles blasted out from the nozzle outlet.
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| 次年度使用額が生じた理由 |
Due to restrictions on travel caused by the COVID19 pandemic, expenditures relating to travel expenses (e.g. conferences) and personel (part-time research assistant) could not be implemented in the first year of project. Consequently, some article expenditures have also been postponed.
As the COVID19 situation improves worldwide, it is expected that funds for travel, personel and remaining articles will be used in the second year of the project.
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