1997 Fiscal Year Final Research Report Summary
Measurement of Rarefied Gas Flow by OPMS (Optical Pressure Measurement System)
| Project/Area Number |
08650227
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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 | Meijo University |
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Principal Investigator |
FUJIMOTO Tetsuo Meijo Univ., Faculty of Sci.& Tech., Prof., 理工学部, 教授 (00023028)
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| Co-Investigator(Kenkyū-buntansha) |
NIIMI Tomohide Nagoya Univ., Faculty of Eng., Associate Prof., 大学院・工学研究科, 助教授 (70164522)
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| Project Period (FY) |
1996 – 1997
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| Keywords | rarefied gas / pressure measurement / optical measurement / fluorescence |
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| Research Abstract |
An optical pressure measurement system utilizing pressure sensitive paint which is based on the O_2 quenching of luminescence has been developed. The pressure sensitive paint is consist of Pt-Octaethelporphyrin or phthalocyanine as luminophore and O_2-permeable silicon polymer as matrix. Variation of strength of luminescence with change of partial pressure of oxigen is studied experimentally in the pressure range from 760 to 10^<-3> Torr and temperature range from 30 to 80 degree Celsius. A painted sample is radiated by UV light of wave length 390nm and fluorescence of wave length of 650nm from luminophore is detected by a CCD camera and the data are processed by a PC.
Following results have been obtained :
1.Ratio of fluorescence intensity I at pressure P to fluorescence intensity I_<ref> at a reference pressure P_<ref> satisfies the Stern-Volmer relation,
<<numerical formula>>
Taking into account the effect of the paint thickness, the above relation is modified, giving
<<numerical formula>>
However, the coefficient of square term is very small compared with the one of the linear term. The Stern-Volmer relatiion is not satisfied for P/P_<ref> less than 0.1. In this range dI/dP is large, showing the high sensitivity to the pressure.
2.Absolute fluorescence intensity depends on the temperature. The relation betweem P/P_<ref> and P/P_<ref> does not depend on the temperature in the range P/P_<ref> larger than 0.1. Decrease of fluorescence with increase of temperature may be attributable to the decrease of morecular populatiion in the ground state of the luminophore.
3.Absolute strength of fluorescence decreases with lapse of time, keeping the experimental condition unaltered. After 24 hours, the strength of fluorescece becomes about 80% PtOEP and about 60% for phtalocyanine. However, relation between P/P_<ref> and I/I_<ref> does not change in spite of laspe of time.
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Research Products
(3 results)
