Optical diagnostics of intermittent flows

V.L. Okulov, I.V. Naumov, Jens Nørkær Sørensen

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

The efficiency of combined use of different optical techniques for flow diagnostics is demonstrated with the practically important case of intense swirling flows. It is shown that, when applied separately, commonly used optical measuring techniques, such as laser Doppler anemometry and particle image velocimetry, frequently give erroneous results, especially for the transition flow and developed nonstationary flow. However, their combined use in diagnostics of unsteady (intermittent) flows significantly improves both the temporal and spatial resolution of measurements. Such a complex approach is for the first time applied for diagnostics of the flow pattern in a closed cylinder with a rotating end face with the aim of studying the changeover from the steady axisymmetric to unsteady asymmetric flow over a wide range of flow parameters. It is found that such a transition is notable for azimuthal disturbances with characteristic modes and frequencies.
Original languageEnglish
JournalTechnical Physics
Volume52
Issue number5
Pages (from-to)583-592
ISSN1063-7842
DOIs
Publication statusPublished - 2007

Cite this

Okulov, V.L. ; Naumov, I.V. ; Sørensen, Jens Nørkær. / Optical diagnostics of intermittent flows. In: Technical Physics. 2007 ; Vol. 52, No. 5. pp. 583-592.
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Optical diagnostics of intermittent flows. / Okulov, V.L.; Naumov, I.V.; Sørensen, Jens Nørkær.

In: Technical Physics, Vol. 52, No. 5, 2007, p. 583-592.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - Optical diagnostics of intermittent flows

AU - Okulov, V.L.

AU - Naumov, I.V.

AU - Sørensen, Jens Nørkær

PY - 2007

Y1 - 2007

N2 - The efficiency of combined use of different optical techniques for flow diagnostics is demonstrated with the practically important case of intense swirling flows. It is shown that, when applied separately, commonly used optical measuring techniques, such as laser Doppler anemometry and particle image velocimetry, frequently give erroneous results, especially for the transition flow and developed nonstationary flow. However, their combined use in diagnostics of unsteady (intermittent) flows significantly improves both the temporal and spatial resolution of measurements. Such a complex approach is for the first time applied for diagnostics of the flow pattern in a closed cylinder with a rotating end face with the aim of studying the changeover from the steady axisymmetric to unsteady asymmetric flow over a wide range of flow parameters. It is found that such a transition is notable for azimuthal disturbances with characteristic modes and frequencies.

AB - The efficiency of combined use of different optical techniques for flow diagnostics is demonstrated with the practically important case of intense swirling flows. It is shown that, when applied separately, commonly used optical measuring techniques, such as laser Doppler anemometry and particle image velocimetry, frequently give erroneous results, especially for the transition flow and developed nonstationary flow. However, their combined use in diagnostics of unsteady (intermittent) flows significantly improves both the temporal and spatial resolution of measurements. Such a complex approach is for the first time applied for diagnostics of the flow pattern in a closed cylinder with a rotating end face with the aim of studying the changeover from the steady axisymmetric to unsteady asymmetric flow over a wide range of flow parameters. It is found that such a transition is notable for azimuthal disturbances with characteristic modes and frequencies.

U2 - 10.1134/S1063784207050088

DO - 10.1134/S1063784207050088

M3 - Journal article

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SP - 583

EP - 592

JO - Technical Physics

JF - Technical Physics

SN - 1063-7842

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