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Methodologies for velocimetry and flow visualization in supersonic flows enabled by CO2 seeding

Han, Lei ; Gao, Qiang LU ; Shan, Yuan ; Li, Bo LU and Li, Zhongshan LU (2025) In Optics and Laser Technology 184.
Abstract

A high spatiotemporal resolution technique for instantaneous flow field measurement has been developed, enabling one-dimensional velocimetry and flow field visualization within a converging–diverging nozzle. By employing femtosecond laser-induced long-lived, high-intensity plasma emission in a CO2/N2 gas flow, coupled with an ICCD camera, we achieved instantaneous one-dimensional velocity measurements at a frequency of 330 kHz. Spectral analysis indicated that the femtosecond laser-induced plasma emission predominantly originates from the CN (B-X) transition. The intensity and lifetime of the plasma emission were found to be closely dependent on the CO2 concentration, with 1 % CO2 providing... (More)

A high spatiotemporal resolution technique for instantaneous flow field measurement has been developed, enabling one-dimensional velocimetry and flow field visualization within a converging–diverging nozzle. By employing femtosecond laser-induced long-lived, high-intensity plasma emission in a CO2/N2 gas flow, coupled with an ICCD camera, we achieved instantaneous one-dimensional velocity measurements at a frequency of 330 kHz. Spectral analysis indicated that the femtosecond laser-induced plasma emission predominantly originates from the CN (B-X) transition. The intensity and lifetime of the plasma emission were found to be closely dependent on the CO2 concentration, with 1 % CO2 providing optimal performance for velocity measurements. In the CO2/N2 mixture, CO2 undergoes a phase transition to solid nanoparticles under specific temperature and pressure conditions, facilitating high spatiotemporal resolution visualization of flow structures via Rayleigh scattering. The instantaneous images captured the morphology of barrel shocks and normal shocks, as well as the effects of varying release pressures and CO2 concentrations on Rayleigh scattering.

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author
; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Flow visualization, MTV, Supersonic flows, Velocimetry
in
Optics and Laser Technology
volume
184
article number
112418
pages
9 pages
publisher
Elsevier
external identifiers
  • scopus:85214097598
ISSN
0030-3992
DOI
10.1016/j.optlastec.2025.112418
language
English
LU publication?
yes
additional info
Publisher Copyright: © 2025 Elsevier Ltd
id
d734b3af-203a-46b9-9e29-271f8beca612
date added to LUP
2025-01-27 09:03:28
date last changed
2025-04-04 15:41:32
@article{d734b3af-203a-46b9-9e29-271f8beca612,
  abstract     = {{<p>A high spatiotemporal resolution technique for instantaneous flow field measurement has been developed, enabling one-dimensional velocimetry and flow field visualization within a converging–diverging nozzle. By employing femtosecond laser-induced long-lived, high-intensity plasma emission in a CO<sub>2</sub>/N<sub>2</sub> gas flow, coupled with an ICCD camera, we achieved instantaneous one-dimensional velocity measurements at a frequency of 330 kHz. Spectral analysis indicated that the femtosecond laser-induced plasma emission predominantly originates from the CN (B-X) transition. The intensity and lifetime of the plasma emission were found to be closely dependent on the CO<sub>2</sub> concentration, with 1 % CO<sub>2</sub> providing optimal performance for velocity measurements. In the CO<sub>2</sub>/N<sub>2</sub> mixture, CO<sub>2</sub> undergoes a phase transition to solid nanoparticles under specific temperature and pressure conditions, facilitating high spatiotemporal resolution visualization of flow structures via Rayleigh scattering. The instantaneous images captured the morphology of barrel shocks and normal shocks, as well as the effects of varying release pressures and CO<sub>2</sub> concentrations on Rayleigh scattering.</p>}},
  author       = {{Han, Lei and Gao, Qiang and Shan, Yuan and Li, Bo and Li, Zhongshan}},
  issn         = {{0030-3992}},
  keywords     = {{Flow visualization; MTV; Supersonic flows; Velocimetry}},
  language     = {{eng}},
  publisher    = {{Elsevier}},
  series       = {{Optics and Laser Technology}},
  title        = {{Methodologies for velocimetry and flow visualization in supersonic flows enabled by CO<sub>2</sub> seeding}},
  url          = {{http://dx.doi.org/10.1016/j.optlastec.2025.112418}},
  doi          = {{10.1016/j.optlastec.2025.112418}},
  volume       = {{184}},
  year         = {{2025}},
}