| Project/Area Number |
04650147
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Fluid engineering
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| Research Institution | Nagoya University |
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Principal Investigator |
NIIMI Tomohide Nagoya Univ., Faculty of Eng., Associate Prof., 工学部, 助教授 (70164522)
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| Co-Investigator(Kenkyū-buntansha) |
FUJIMOTO Tetsuo Nagoya Univ., Faculty of Eng., Prof., 工学部, 教授 (00023028)
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| Project Period (FY) |
1992 – 1993
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| Project Status |
Completed (Fiscal Year 1993)
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| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1993: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1992: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Keywords | PLIF / Oxygen Molecule / Temperature Measurement / Two-dimensional Measurement / Visualized Image / Rarefied Gas Flow / Laser Sheet / Picture Processing / PLIF / 高感度CCDカメラ / 希薄気体 |
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| Research Abstract |
Oxygen molecules have the absorption bands in the broad range from 114 inthe ultra violet to 1580 nm in the infrared. The dominant Schumann-Runge absorption band system corresponds to the transition of the ground state CHI^3SIGMA_8^-to the excited state BETACHI^3SIGMA_u^-, and has the discrete absorption bands from 175to 250 nm and the continuum ones from 130 to 175 nm. The BETA state has been known to be crossed by many repulsive potential curves and to be predissociated. Sincethe strong predissociation rate makes the lifetime of the fluorescence short in the order of 10^<-12> seconds, it is possible to assume that the fluorescence yields prior to the intermolecular collision.
In this study, we investigate the capability of imaging of rarefied gas flow using O_2-LIPF(Laser-Induced Predissociative Fluorescence). Since oxygen isone of main component of air, O_2-LIPF may make it possible to visualize the air flow in the high speed wind tunnel without the tracer. However, because the visualization of the flow field below the room temperature using O_2-LIPF is verydifficult, it has been applied only to the high entalpy and combustion flow^<(1)>, not to high speed flow with low temperature. In this study, the rarefied oxygen flow is visualized by O_2-LIPF, using an ArF excimer laser (193 nm) and a high-sensitive CCD camera. If long exposure time (1200 seconds) of the CCD camera is set and the scattered laser beam is suppressed sufficiently, the oxygen flow below the room temperature using O_2-LIPF can be imaged successfully.
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