Skip to Main Content
 

Global Search Box

 
 
 
 

Files

File List


MS thesis Yvonne Hung final version.pdf (2.67 MB)

ETD Abstract Container

Abstract Header

CARS Measurements of Vibrational Energy Transfer in Nanosecond Pulse Electric Discharges in Nitrogen, Air, and Their Mixtures with Carbon Dioxide

Hung, Yi-chen, Hung
http://rave.ohiolink.edu/etdc/view?acc_num=osu1468959981

Abstract Details

2016, Master of Science, Ohio State University, Chemical Physics.
Vibrational relaxation of nitrogen accelerated by rapid energy transfer to CO2 is studied in the afterglow of a diffuse filament ns pulse discharge. Time-resolved N2(v=0-3) vibrational level populations and temperature are measured using broadband Coherent Anti-Stokes Raman Spectroscopy (CARS). Rotational-translational temperature in the afterglow is inferred from partially rotationally resolved structure of N2(v=0) band. The measurements have been done in nitrogen, dry air, and their mixtures with CO2. N2 vibrational excitation in the discharge occurs by electron impact, with subsequent vibration-vibration (V-V) energy transfer within N2 vibrational manifold, vibration-translation (V-T) relaxation, and near-resonance V-V' energy transfer from N2 to CO2 asymmetric stretch vibrational mode. The results show that rapid V-V' energy transfer to CO2, followed by intramolecular energy redistribution to symmetric stretch and bending modes of CO2 and their V-T relaxation, considerably accelerate the net rate of energy thermalization and temperature rise in the afterglow. The effect of accelerated N2 vibrational relaxation may explain localized thermal perturbations detected in filamentary, ns pulse, surface dielectric barrier discharges in quiescent room air, on the time scale of several hundred microsecond, which matches the estimated vibrational relaxation time of nitrogen by water vapor at these conditions. The present results are consistent with previous CARS measurements of N2 vibrational temperature distribution in the nonequilibrium supersonic shear layer, which demonstrated that CO2 injection results in its significant reduction, thereby strongly affecting the flow field. The present results show that significant amounts of vibrational energy can be stored in nonequilibrium nitrogen and air flows and released at a desired location, using local injection of rapid “relaxer” species such as CO2 or hydrocarbons and providing significant effect on the high-speed flow, at the conditions when water vapor concentration in the flow is low (e.g. in high-altitude flight).
Igor Adamovich (Committee Member)
Heather Allen (Committee Member)
67 p.
Physical Chemistry
CARS Measurements, Vibrational Energy Transfer, Nanosecond Pulse Electric Discharges

Recommended Citations

Citations

  • Hung, Hung, Y.-C. (2016). CARS Measurements of Vibrational Energy Transfer in Nanosecond Pulse Electric Discharges in Nitrogen, Air, and Their Mixtures with Carbon Dioxide [Master's thesis, Ohio State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=osu1468959981

    APA Style (7th edition)

  • Hung, Hung, Yi-chen. CARS Measurements of Vibrational Energy Transfer in Nanosecond Pulse Electric Discharges in Nitrogen, Air, and Their Mixtures with Carbon Dioxide. 2016. Ohio State University, Master's thesis. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=osu1468959981.

    MLA Style (8th edition)

  • Hung, Hung, Yi-chen. "CARS Measurements of Vibrational Energy Transfer in Nanosecond Pulse Electric Discharges in Nitrogen, Air, and Their Mixtures with Carbon Dioxide." Master's thesis, Ohio State University, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=osu1468959981

    Chicago Manual of Style (17th edition)

osu1468959981
803
© 2016, all rights reserved.
This open access ETD is published by The Ohio State University and OhioLINK.