2002 Fiscal Year Final Research Report Summary
Micro-scale Analysis of Non-equilibrium Phenomena in Highly Rarefied Gas Flows
| Project/Area Number |
13450072
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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 | 一般 |
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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 Engg., Prof., 工学研究科, 教授 (70164522)
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| Co-Investigator(Kenkyū-buntansha) |
NAKAYAMA Hiroshi Nagoya Univ., Faculty of Engg., Research Assoc., 工学研究科, 助手 (40303656)
HIROTA Masafumi Nagoya Univ., Faculty of Engg., Associate Prof., 工学研究科, 助教授 (30208889)
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| Project Period (FY) |
2001 – 2002
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| Keywords | Micro-Scale / Highly Rarefied Gas Flow / REMPI / Gas-Surface Interaction / Free Molecular Flow / PSP / Non-Equilibrium / Temperature Measurement |
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| Research Abstract |
In this study, we develop the experimental system for 2R+2 N_2-REMPI and apply it to measurement of rotational temperature in a supersonic free molecular nitrogen flow. In the 2R+2 N_2-REMPI technique, nitrogen molecules are ionized, the nitrogen ions are detected as a signal and its spectra depending on the wavelength of an irradiated laser beam are analyzed to measure the rotational temperature through the Boltzmann plot. However, it is found from the experimental results that the number of molecules in the rotational states is not given by the Boltzmann distribution at the measurement point, showing the so-called non-Boltzmann distribution. Now, we are carrying out experiments changing the source pressure and the measurement point as parameters, to clarify the transition from the equilibrium to non-equilibrium in the rotational mode and to obtain the functional form of the non-Boltzmann distribution.
The pressure range of Pressure sensitive paints (PSP) has been limited above 1 Torr (133.3 Pa) and there is no application to lower pressure range because the pressure sensitivity seems to be not so high in that range. In this study, we apply three types of PSP to the rarefied gas flow mainly lower than 1 Torr and examine those fundamental property, such as pressure/temperature sensitivity and time decay of luminescence and so on. Both PtTFPP/poly(TMSP) and Bath-Ru/AA have high sensitivity in the range of pressure lower than 1 Torr. Since the absolute luminescence intensity of PtTFPP/poly(TMSP) is higher than that of Bath-Ru/AA, however, it may better to use the former, judging from a point of S/N.
Using laser induced fluorescence (LIF) of NO seeded in the carrier gas N_2 and a pressure sensitive paint [PtTFPP/poly(TMSP)], we visualize and analyze the flow field structures around the linear-type aerospike nozzle and the complicated pressure distribution on the spike surface successfully.
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