2007 Fiscal Year Final Research Report Summary
SEPARATION OF SMALL BUBBLE FROM GAS FLOW INJECTED INTO TURBULENT BOUNDARY LAYER
| Project/Area Number |
18560175
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Fluid engineering
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| Research Institution | Osaka City University |
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Principal Investigator |
KATOH Kenji Osaka City University, Department of Mechanical Engineering, Professor (10177438)
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| Project Period (FY) |
2006 – 2007
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| Keywords | Self Assembled Monolavers (SAMs) / Wetting / Contact Angle / Liquid Droplet / Surface Tension / Inclined Plate / Sliding Angle |
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| Research Abstract |
There has been no exact theory to predict the sliding angle of liquid droplet on the inclined plate. In this study, based on the macroscopic wetting behavior , the theoretical model to calculate the sliding angle was discussed from the force balance between the gravitational force and the surface tension acting on the droplet. The results of sliding angles agreed very well with those of experiments for each combination between three kinds of test liquids and solid plates. The profile of three dimensional liquid droplet on the inclined plate was obtained from an approximate theory and the results agreed well with measured profiles by photograph.
In order to detect the microscopic defect on the Self Assembled Monolayers (SAMs) as simple as possible, we discussed the possibility of the method by use of sliding angles stated above. The test plates of SAMs on the silicon wafer were made by the immersion method for four kinds of immersion time. First, the contact angles on the SAMs plates were measured experimentally by the method proposed by the authors. The results showed that there appeared the difference of contact angle hysteresis 1〜2degrees between homogeneous standard film and other films with defect of molecular order. This indicates that the macroscopic wetting characteristics is dependent on the microscopic defect on the solid surface. Next, the sliding angles on SAMs were measured for the droplet with volume of1μ1. The difference of sliding angle between standard film and other films with defect were 6 degrees, which is much larger than the difference of contact angle hysteresis stated above. The defect on SAMs may be detected easily from the measurement of sliding angles.
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[Presentation] 傾斜平板上の液滴の転落体積2008
Author(s)
西田 達史, 加藤 健司
Organizer
日本機械学会関西支部第83期定時総会講演会
Place of Presentation
大阪大学
Year and Date
2008-03-15
Description
「研究成果報告書概要(和文)」より
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