Speckle photography applied to statistical analysis of turbulence

Фомин, Н. А.; Lavinskaja, E.; Merzkirch, W.; Vitkin, D.

doi:10.1016/s0030-3992(99)00029-8

Cited by 12 publications

(8 citation statements)

References 13 publications

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“…Classical techniques, such as shadowgraphy, interferometry or absorption, also allow the 3D distributions of physical observable to be reconstructed using images of the flow taken at different directions. For a given test object, the quality of the tomographic reconstruction depends on the number of projections taken, the covered total angular range of viewing directions, and the amount of information available from each projection [18].…”

Section: Reconstruction Using Radon Integral Inversionmentioning

confidence: 99%

“…A numerical procedure of solving this ray equation is described in [18] and allows the computation of the ray positions and the slope for a small increment in path length starting from the initial cross-section where the rays are parallel to the z-axis. To perform the ray tracing, a field of the refractive index should be prescribed.…”

Section: Ray Tracing Through Turbulent Refractive Index Fieldmentioning

confidence: 99%

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Limited projections laser speckle tomography of complex flows

Фомин

Lavinskaya

Takayama

2006

Optics and Lasers in Engineering

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Section: Reconstruction Using Radon Integral Inversionmentioning

confidence: 99%

Section: Ray Tracing Through Turbulent Refractive Index Fieldmentioning

confidence: 99%

Limited projections laser speckle tomography of complex flows

Фомин

Lavinskaya

Takayama

2006

Optics and Lasers in Engineering

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“…However, using laser light in the formation of speckle pattern made it possible to determine deflection of light ray quantitatively in the existence of a phase object (Kopf 1972), During the last three decades speckle photography was apphed in various fluid mechanics and combustion problems for both rectangular and cylindrical flow fields and these studies demonstrate that, the technique can generate qualitative results (Farrell and Hofeldt 1984, Erbeck and Merzkirch 1988, Keller and Merzkirch 1990, Shakher et al 1994, Fomin et al 1999, Alkislar 2001). …”

Section: Laser Speckle Displacement (Lsd) Techniquementioning

confidence: 99%

Active Control of High Speed Jet Flames Using Counterflow

Krothapalli¹,

Lourenco²,

Koc-Alkislar³

2003

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Public reporting burden for this collection of information is estimated to average 1 hour per reqwnse, including the time for reviewing instructions, searching data sources, gathering and maintaining the data needed, and completing and reviewing tlie collection of information. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES)Office of Naval research 100 Alabama St NW Suit 4R15 Atlanta, GA 30303-3104 12, DISTRIBUTION AVAILABILITY STATEMENTApproved for public release, distribution is unlimited. DU ABSTRACT -^^^-^^--^^_^^^_^^^___^^-_^^_«^^__Countercurrent flow control was applied as a novel flame stabilization technique on a premixed jet flame. In the experimental setup a converging nozzle burner was placed concentrically in a suction collar to generate suction driven countercurrent flow. Flame blow off velocity was measured at different suction velocity and equivalence ratio values. Tests show that by applying countercurrent flow around the periphery of a jet flame It can be stabilized up to jet exit velocity of 40 m/s. Particle Image Veloclmetry (PIV) measurements and shadowgraph visualizations reveal that, application of suction changes the shear layer structure. An optical temperature measurement technique, refereed to as Laser Speckle Displacement (LSD) was developed for instantaneous temperature field measurements. It Is shown that the technique is easy to irriplement and can be used in conjunction with PIV for simultaneous velocity and temperature measurements In reacting flows. SUBJECT TERMS --^^-^^-^^^-^^-.^^_^^--^^^--Premixed jet flame, flame stabilization, countercurrent flow, speckle photography, particle image veloclmetry

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“…The emergence of Speckle Photography followed by Digital Speckle Photography has facilitated the observation of optical inhomogeneities over entire test bodies (Fomim et al, 1999). Speckle photography uses image correlation software to quantify the shift that a laser specklegram undergoes when observed through a test section.…”

Section: Introductionmentioning

confidence: 99%

An improved, free surface, topographic technique

Fouras

Hourigan

Kawahashi

et al. 2006

J Vis

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Current techniques of water wave visualization such as shadowgraphy and stereo photography are widely used but are deficient in many aspects. Refraction based visualization observes the bending of light as it traverses across a liquid-air interface. This work describes the continued development of techniques to measure the surface height of a liquid free surface. The method, Reference Image Topography, utilizes refraction of light at the free surface as a function of the local angle of that surface. Particle Image Velocimetry (PIV) software is used to evaluate apparent dislocations of the target image viewed through the free surface, which are approximately proportional to the surface angle. High-resolution images are presented of the dynamic surface topography for a point source and the shallow water flow around a vertical cylinder.

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Speckle photography applied to statistical analysis of turbulence

Cited by 12 publications

References 13 publications

Limited projections laser speckle tomography of complex flows

Limited projections laser speckle tomography of complex flows

Active Control of High Speed Jet Flames Using Counterflow

An improved, free surface, topographic technique

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