Abstract
To support the determination of total specific enthalpy of the plasma flow of the 60 MW Interaction Heating Facility at NASA Ames Research Center, spectroscopic measurements of non-equilibrium emission were performed in the free stream. In the visible-near infrared wavelength region, the most prominent emission was from molecular N2, and in the ultra violet region, the spectra were dominated by emission from molecular NO. The only atomic lines observed were those of copper (an erosion product of the electrodes). The bands of the 1st Positive system of N2 (B➜A) differed significantly from spectra computed spectra assuming only thermal excitation, suggesting overpopulation of the high vibrational states of the B state of N2. Populations of these high vibrational levels (peaking at vupper=13) of the N2 B state were determined by scaling spectra simulated for each upper vibrational state separately. The initially manual scaling process has been replaced with an automated multiparameter scaling to determine the population of the vibrationally excited N2 states. The overpopulation of the high vibrational levels is assigned to inverse pre-dissociation of neutral atoms into the N2 B state at vupper>10 via level crossing processes with the N2 A’5∑g+ state. The v=13 emission has been used to determine N atom densities which agree very well between the different experiment campaigns both with manual and automated fitting and also with the CFD simulation of these flows.
Original language | English |
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Title of host publication | 46th AIAA Plasmadynamics and Lasers Conference |
DOIs | |
State | Published - 2015 |
Event | 46th AIAA Plasmadynamics and Lasers Conference, 2015 - Dallas, United States Duration: Jun 22 2015 → Jun 26 2015 |
Publication series
Name | 46th AIAA Plasmadynamics and Lasers Conference |
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Conference
Conference | 46th AIAA Plasmadynamics and Lasers Conference, 2015 |
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Country/Territory | United States |
City | Dallas |
Period | 6/22/15 → 6/26/15 |
Bibliographical note
Publisher Copyright:© 2015, American Institute of Aeronautics and Astronautics Inc, AIAA. All Rights Reserved.
ASJC Scopus subject areas
- Electrical and Electronic Engineering
- Condensed Matter Physics