2000 Fiscal Year Final Research Report Summary
Development of the Diode-Laser Absorption Spectroscopy System for the Diagnostics of High-Temperature Flows.
| Project/Area Number |
10555334
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| Research Category |
Grant-in-Aid for Scientific Research (B).
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| Allocation Type | Single-year Grants |
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| Section | 展開研究 |
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| Research Field |
Aerospace engineering
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| Research Institution | The university of Tokyo |
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Principal Investigator |
ARAKAWA Yoshihiro Graduate School of Engineering, The university of Tokyo, Professor, 大学院・工学系研究科, 教授 (50134490)
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| Co-Investigator(Kenkyū-buntansha) |
FUJIWARA Toshitaka Graduate School of Engineering, Nagoya University, Professor, 大学院・工学研究科, 教授 (90023225)
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| Project Period (FY) |
1998 – 2000
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| Keywords | Absorption Spectroscopy / High-Enthalpy Flows / Diode-Laser |
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| Research Abstract |
In this academic year, we conducted spectroscopic measurements on high-enthalpy plumes generated in the wind tunnels at the university of Tokyo, Nagoya university, the Japan ultra-high temperature material research center (Nagoya), the national aerospace laboratory (Chofu), and the university of Stuttgart (Germany). The results are summarized as follows.
1) Three-dimensional determination of arcjet argon-plume properties was achieved by computer tomographic reconstruction.
2) In order to get the information of high-temperature air plume, we accessed to the atomic oxygen absorption line at the wavelength of 777.19 nm and successfully measured the translational temperature and the number density of excited atomic oxygen. From the measured three-dimension distribution, the diffusive mixing process of oxygen gas into nitrogen gas was clarified, and owing to this process, the degree of dissociation in the plume generated by constrictor-type arc-wind tunnels was found lower than the expected value.
3) In the repetitively discharging inductive-heating wind tunnel, we succeeded in measuring the profiles of temperature and number density of atomic oxygen in high-temperature pure-oxygen flows.
4) Diagnosis of the optically thick plumes, which is quite difficult for the Laser Induced Florescence or Emission Spectroscopy measurements, has been successfully done using Laser absorption spectroscopy. (The maximum absorption reached at 97%)
5) The portability and wide-usage of our laser diagnostic system has been demonstrated by transporting and applying it to the wind tunnels located at Nagoya, Tokyo and Stuttgart, Germany.
6) For the future improvement of system performance and for the measurement of ground level number density, the increase in its sensitivity by several orders of magnitude would be essential.
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