Shock tube study of weakly ionized plasmas using laser absorption spectroscopy of excited state oxygen atoms
Abstract/Contents
- Abstract
- This work studies the collisional excitation kinetics of atomic oxygen diluted in argon at extreme temperatures (8,000 - 11,000 K) in a shock tube. Two lasers at 777 and 926 nm were scanned across the transitions of atomic oxygen at a rate of 25 kHz, providing the absorbance time histories within the 0.5-1 ms test time after the reflected shock passed. Four key quantities were measured in the current work to understand the collisional excitation kinetics, namely, the number density of the: fourth level of atomic oxygen; sixth level of atomic oxygen; electrons; and heavy-particle translational temperature. The number density of atomic oxygen and heavy-particle translational temperature were inferred from the integrated area and the Doppler linewidth of the measured oxygen absorbance. A preliminary two-temperature collisional-radiative model was developed to explain the multi-stage behavior of the measured oxygen number density time histories from 8,000 to 10,000 K. Reaction rate constants were fitted to match the measured excited-state atomic oxygen time histories. A sensitive, in-situ electron number density diagnostic method was developed by measuring the Stark shift of excited-state atomic oxygen. The measured electron number density was consistent with the preliminary model. The kinetics model was revised to match the measured time histories from 10,000 to 11,000 K.
Description
| Type of resource | text |
|---|---|
| Form | electronic resource; remote; computer; online resource |
| Extent | 1 online resource. |
| Place | California |
| Place | [Stanford, California] |
| Publisher | [Stanford University] |
| Copyright date | 2021; ©2021 |
| Publication date | 2021; 2021 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Author | Li, Yang |
|---|---|
| Degree supervisor | Hanson, Ronald |
| Thesis advisor | Hanson, Ronald |
| Thesis advisor | Cappelli, Mark A. (Mark Antony) |
| Thesis advisor | Hollberg, Leo (Leo William) |
| Degree committee member | Cappelli, Mark A. (Mark Antony) |
| Degree committee member | Hollberg, Leo (Leo William) |
| Associated with | Stanford University, Department of Mechanical Engineering |
Subjects
| Genre | Theses |
|---|---|
| Genre | Text |
Bibliographic information
| Statement of responsibility | Yang Li. |
|---|---|
| Note | Submitted to the Department of Mechanical Engineering. |
| Thesis | Thesis Ph.D. Stanford University 2021. |
| Location | https://purl.stanford.edu/hd185ts2885 |
Access conditions
- Copyright
- © 2021 by Yang Li
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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