Abstract
In highly rarefied gas flows, there appear nonequilibrium phenomena not only between translational and rotational energy modes (non-equipartition) but also deviation of rotational energy distribution from the Boltzmann distribution. To analyze these highly rarefied gas flows, we established the experimental system for 2R + 2 N2-REMPI and applied it to the measurement of rotational temperature in a supersonic free molecular flow of nitrogen. In this study, a strong nonequilibrium in rotational energy mode has been found in a nitrogen free molecular flow. The data in the Boltzmann plot, obtained from the measured REMPI spectra, cannot be fitted by one line but approximately by two lines, revealing the non-Boltzmann distribution of rotational energy in the ground state. The mechanism of the deviation from the Boltzmann distribution is also discussed using the state-to-state transition rates for collisional relaxation.
Original language | English |
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Pages (from-to) | 623-629 |
Number of pages | 7 |
Journal | Nippon Kikai Gakkai Ronbunshu, B Hen/Transactions of the Japan Society of Mechanical Engineers, Part B |
Volume | 69 |
Issue number | 679 |
DOIs | |
Publication status | Published - Mar 2003 |
Externally published | Yes |
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Mechanical Engineering