Temperature measurement in gases using speckle photography

Farrell, Patrick V.; Hofeldt, David L.

doi:10.1364/ao.23.001055

Cited by 90 publications

(24 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…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%

“…The trade off in the application is, for temperature measurements the vertical beam deviation has to be assumed negligible. Farrell and Hofeldt (1984) used speckle photography to measure temperature distribution in an axisymmetric propane flame with tiie apphcation of inverse Abel transform. However, their study was limited by the spatial resolution of deflection data.…”

Section: Laser Speckle Displacement (Lsd) Techniquementioning

confidence: 99%

See 1 more Smart Citation

Active Control of High Speed Jet Flames Using Counterflow

Krothapalli¹,

Lourenco²,

Koc-Alkislar³

2003

View full text Add to dashboard Cite

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

show abstract

Section: Laser Speckle Displacement (Lsd) Techniquementioning

confidence: 99%

Section: Laser Speckle Displacement (Lsd) Techniquementioning

confidence: 99%

Active Control of High Speed Jet Flames Using Counterflow

Krothapalli¹,

Lourenco²,

Koc-Alkislar³

2003

View full text Add to dashboard Cite

show abstract

“…Thus, the speckle photography method allows direct determination of the refraction angle at axisymmetric inhomogeneities. Only in this case, the refraction coefficient distribution may be reconstructed using relation (8), as done by Farrell and Hofeldt (1984) and Wernekinck (1985). Formula (7) for speckle shifts must be used for tomographic reconstruction of asymmetric distributions of the refraction coefficient.…”

Section: Schematic Of the Experimental Set-upmentioning

confidence: 99%

Speckle tomography of a gas flame

Blinkov¹,

Фомин²,

Rolin³

et al. 1989

Experiments in Fluids

View full text Add to dashboard Cite

Abstract. The present work is concerned with an experimental setup for studying phase objects using multi-directional speckle photography. A mathematical description of light propagation in an optically inhomogeneous medium and a means of speckle tomography of refractive coefficient distributions are given. Recommendations on two-dimensional refractive coefficient and temperature distributions in a flame of a candle illuminated in four directions are made. The obtained results evidence that speckle photography may be a basis for tomographic studies of temperature fields in different cross-sections of an object. A speckle shift error is about 5% while the one in reconstructing local temperatures does not exceed 10%.

show abstract

“…In a group of optical methods which are called index of refraction methods, the temperature distribution is obtained from variation of index of refraction or spatial derivatives of index of refraction. Holographic interferometry [1], Moiré deflectometry [2], Laser speckle photography [3], Shearing interferometry [4], Speckle Shearing interferometry [5], Talbot interferometry [6], Lau phase interferometry [7] and Mach-Zehnder interferometry are a few examples of these methods.…”

Section: Introductionmentioning

confidence: 99%