Abstract
The present study is concerned with adopting of a Talbot effect-based technique for analyzing flows with random phase inhomogeneities. It is shown that this method is a powerful tool for diagnostics of turbulent flows. The potential of the technique is illustrated by measuring mean and fluctuating values of admixture concentration of two-dimensional turbulent helium jet issuing into the ambient air. Averaged air and helium concentrations throughout the flow field are determined using local light refraction measurements with a high spatial resolution from a long-exposed Talbot image of the jet. The analysis of light intensity distributions in light spots of a Talbot-image shows that the jet turbulence is inhomogeneous and anisotropic. Quantitative information on rms fluctuations of concentration gradients throughout the flow field is obtained from local photometric measurements at the Talbot light spots.
Similar content being viewed by others
References
Andreyev AM, Ginzburg VM, Ramishvili NM (1989) The use of the Talbot effect in dynamic measurements of deformed liquid/gas interface surface shape. Opt Commun 73:429–433
Boreisho AS, Koryakovsky AS, Marchenko VM (1985) Investigation of the optical quality of gas flows produced by nozzle array. J Tech Phys 55:1943–1949
Doroshko MV, Penyazkov OG, Rankin G, Khramtsov PP, Shikh IA (2005) Talbot effect-based technique study of two-dimensional turbulent flow past a horizontal cylinder. In: Heat and Mass Transfer-2005, Minsk: A. V. Luikov Heat and Mass Transfer Inst, pp 210–214
Doroshko MV, Penyazkov OG, Rankin G, Khramtsov PP, Shikh IA (2006) Talbot effect-based technique in measurements of an axis-symmetrical turbulent jet. JEPTER 79:1–6
Ebbeni J (1970) Nouveaux aspects du phenomene de moiré. Nouv Rev Opt 1:333–342; 353–358
Koryakovsky AS, Marchenko VM (1981) The probe of the wave front based on Talbot effect. J Tech Phys 51:1432–1438
Koryakovsky AS, Marchenko VM, Prochorov AM (1987) Diffraction theory of Talbot interferometry and diagnostic of wide-aperture wave fronts. Formation and control of optical wave fronts. Nauka Press, Moscow. IOFAN Papers 7:33–91
Lim CS, Srinivasan V (1983) Talbot interferometer with computer generated gratings. Opt Commun 44:219–222
Lohmann AW, Silva DE (1971) An interferometer based on the Talbot effect. Opt Commun 2:413–415
Nakano Y, Murata K (1984) Measurements of phase objects using Talbot effect and moiré techniques. Appl Opt 23:2296–2299
Zhang Q-C, Su X-Y (2002) An optical measurement of vortex shape at a free surface. Opt Laser Technol 34:107–113
Shakher C, Nirala AK (1999) A review on refractive index and temperature profile measurements using laser-based interferometric techniques. Opt Laser Technol 31:455–491
Shakher C, Daniel AJ, Nirala AK (1994) Temperature profile measurement of axisymmetric gaseous flames using speckle photography, speckle shearing interferometry, and Talbot interferometry. Opt Eng 33:1983–1988
Spagnolo GS, Ambrosini D, Paoletti D (2002) Displacement measurement using the Talbot effect with a Ronchi grating. J Opt A Pure Appl Opt 4:376–380
Stricker J, Zakharin B (1997) 3-D turbulent density field diagnostics by tomographic moiré technique. Exp Fluids 23: 76–85
Takeda M, Kobayashi S (1984) Lateral aberration measurements with a digital Talbot interferometer. Appl Opt 23:1760–1764
Talbot F (1836) Facts relating to optical science IV. Philos Mag 9:401–407
Vasiliev LA (1968) Schlieren methods. Nauka Press, Moscow
Voinov Yu P, Zuev GM, Koryakovsky AS (1984) On measurement of the optical quality of gas flows by Talbot interferometry. FIAN Phys Rev Lett 1:13–17
Way J, Libby PA (1970) Hot wire probes for measuring velocity and concentration in helium–air mixtures. AIAA J 8:976–977
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Doroshko, M.V., Khramtsov, P.P., Penyazkov, O.G. et al. Measurements of admixture concentration fluctuations in a turbulent shear flow using an averaged Talbot image. Exp Fluids 44, 461–468 (2008). https://doi.org/10.1007/s00348-007-0348-5
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00348-007-0348-5