Laser Doppler visualisation of the velocity field by excluding the influence of multiparticle scattering

Dubnishchev, Yuri N.; Chugui, Yuri N.; Kompenhans, Jürgen

doi:10.1070/qe2009v039n10abeh014054

Cited by 9 publications

(2 citation statements)

References 4 publications

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“…Optical diagnostics of flows have been successfully applied in experimental hydrodynamics and gas dynamics for a long time. It offers a large variety of modern methods and techniques: shadowgraphy and Schlieren methods [11][12][13], laser Doppler anemometry [13,14], Doppler technologies of velocity field measurements [15,16], and particle image velocimetry [17]. The Hilbert diagnostics of flows [18][19][20][21] based on visualization of space-and-time phase disturbances induced in the light field by the flow passing through the examined medium has a high potential for development and application.…”

Section: Optical Methods Of Diagnosticsmentioning

confidence: 99%

Hydrodynamic Vortex Structures in a Diffusion Jet Flame

Nikolaevich¹,

Vladimirovich²,

Vladimirovich³

et al. 2019

Swirling Flows and Flames

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The chapter presents the results of an experimental study of hydrodynamics and diffusion combustion of jets flowing out of long tubes in the Reynolds number range 200-13,500 into air. The methods used in the experiments are visualization in the ultraviolet region, PIV, and hot-wire anemometry. The amplitude-phase structure of optical filters in systems of the Hilbert diagnostics of phase optical density fields in gaseous and condensed systems was used in this work. A possibility of visualization of disturbances in phase optical density fields with arbitrary amplitudes is demonstrated. Two geometries are studied: jet combustion in a stationary atmosphere and in a cross flow. Propane and hydrogen in a mixture with an inert diluent (CO 2) were used as fuels. In the isothermal jet stream, propane-butane mixture and Freon-22 are used. The main attention in the problem is paid to the mechanism of pipe and jet instability interaction, resulting in the vortex motion in several spatial regions. For critical Reynolds numbers in a pipe, the characteristic is the mechanism of two-stage instability caused by turbulent spot (puff) formation inside the pipe and vortex structure generation in the jet-mixing layer. These vortex structures (puff) exert a strong influence both on the isothermal jet and on the flame.

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Section: Optical Methods Of Diagnosticsmentioning

confidence: 99%

Hydrodynamic Vortex Structures in a Diffusion Jet Flame

Nikolaevich¹,

Vladimirovich²,

Vladimirovich³

et al. 2019

Swirling Flows and Flames

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show abstract

“…General problem DGV is measurement of a field of velocity vectors at the minimal number of channels of registration and an influence of a multi-particle scattering in the laser sheet on result of measurements. The differential method of eliminating the influence of the multi-particle scattering is described in [9]. The opportunity of measurement 2D velocity fields with reduction of dependence on the many-particle scattering is discussed in the present work.…”

Section: Introductionmentioning

confidence: 99%

Laser Doppler Visualization of 2D Velocity Fields with Minimization Dependence from Multi–Particle Scattering

Dubnishchev

Chuguy

Kompenhans

2010

KEM

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The method of laser Doppler visualization and measurement of 2D velocity vector field in flows with minimization of influence of a multi–particle scattering is discussed. The investigated section in the flow is illuminated with a laser sheet. Our approach is based on reception of a pair wise difference of normalized frequency–demodulated images of a laser sheet in light beams scattered in various directions. The 2D velocities field is formed from linear combinations of images of the laser sheet in frequency–demodulated light scattered in directions orthogonal to it.

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