Title: NO PLIF flow visualization and time-resolved temperature distributions in laser induced breakdown plumes

Abstract

NO planar laser induced fluorescence (PLIF) is used to obtain images of laser-induced breakdown plasma plumes in NO-seeded nitrogen and dry air at near atmospheric pressure. Single-shot PLIF-images show that the plume development 5–50 μs after the breakdown pulse is fairly reproducible shot-to-shot, although the plume becomes increasingly stochastic on longer timescales, 100–500 μs. The stochastic behavior of the plume is quantified using probability distributions of the loci of the plume boundary. Analysis of the single-shot images indicates that the mixing of the plume with ambient gas on sub-ms time scale is insignificant. The induced flow velocity in the plume is fairly low, up to 30 m s^–1, suggesting that laser breakdowns are ineffective for mixing enhancement in high speed flows. The ensemble-averaged PLIF images indicate the evolution of the plume from an initially elongated shape to near-spherical to toroidal shape, with a subsequent radial expansion and formation of an axial jet in the center. Temperature distributions in the plume in air are obtained from the NO PLIF images, using two rotational transitions in the NO(X, v' = 0 → A, v'' = 0) band, J'' = 6.5 and 12.5 of the ^QR₁₂ + Q₂ branch. The results indicate thatmore » the temperature in the plume remains high, above 1000 K, for approximately 100 μs, after which it decays gradually, to below 500 K at 500 μs. The residual NO fraction in the plume is ~0.1%, indicating that repetitive laser-assisted ignition may result in significant NO-generation. Furthermore, these measured temperature and velocity distributions can be used for detailed validation of kinetic models of laser-induced breakdown and assessment of their predictive capability.« less

Authors:

van den Bekerom, Dirk C. M.  ^[1];

• Search DOE PAGES for author "van den Bekerom, Dirk C. M."
• Search DOE PAGES for ORCID "0000-0002-7554-2539"

Jans, Elijah R.  ^[2];

• Search DOE PAGES for author "Jans, Elijah R."
• Search DOE PAGES for ORCID "0000-0002-1659-1234"

Adamovich, Igor V.  ^[2]

• Search DOE PAGES for author "Adamovich, Igor V."
• Search DOE PAGES for ORCID "0000-0001-6311-3940"

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+ Show Author Affiliations

1. Sandia National Lab. (SNL-CA), Livermore, CA (United States); The Ohio State Univ., Columbus, OH (United States)
2. The Ohio State Univ., Columbus, OH (United States)

Publication Date:

Thu Apr 22 00:00:00 EDT 2021

Research Org.:

Sandia National Lab. (SNL-CA), Livermore, CA (United States); Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

Sponsoring Org.:

USDOE National Nuclear Security Administration (NNSA)

OSTI Identifier:

1877134

Report Number(s):

SAND2022-8519J
Journal ID: ISSN 0022-3727; 707569

Grant/Contract Number:  

NA0003525; NA0002374

Resource Type:

Accepted Manuscript

Journal Name:

Journal of Physics. D, Applied Physics

Additional Journal Information:

Journal Volume: 54; Journal Issue: 26; Journal ID: ISSN 0022-3727

Publisher:

IOP Publishing

Country of Publication:

United States

Language:

English

Subject:

42 ENGINEERING