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Digital phase-stepping holographic interferometry in measuring 2-D density fields

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Abstract

This paper presents a holographic interferometer technique for measuring transparent (2-D or quasi 2-D) density fields. To be able to study the realization of such a field at a certain moment of time, the field is “frozen” on a holographic plate. During the reconstruction of the density field from the hologram the length of the path traversed by the reconstruction beam is diminished in equal steps by applying a computer controlled voltage to a piezo-electric crystal that translates a mirror. Four phase-stepped interferograms resulting from this pathlength variation are digitized and serve as input to an algorithm for computing the phase surface. The method is illustrated by measuring the basically 2-D density field existing around a heated horizontal cylinder in free convection.

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Abbreviations

λ :

wavelength

x, y :

cartesian coordinate system

Φ :

phase

ΔΦ :

phase step

K :

Gladstone-Dale constant

L :

width of 2-D density field

ϱ :

density

ϱ 0 :

density at reference conditions

I 0, I 1, I 2, I 3 :

recorded interferograms

I mod :

modulation intensity

I bias :

bias intensity

N :

numerator determining tan {ϱ (x, y)}

D :

denominator determining tan {ϕ (x, y)}

θ :

dimensionless temperature

T :

temperature

T c :

temperature of cylinder

T :

temperature of environment

p :

pressure

R :

gas constant

References

  • Becker, F.; Yu, Y. H. 1985: Application of digital interferogram evaluation techniques. AIAA Paper No. 85-0037

  • Carré, P. 1966: Installation et utilisation du comparateur photoélectrique et interférential du Bureau International des Poids et Mesures. Metrologia 2, 13–23

    Google Scholar 

  • Cheng, Y. Y; Wyant, J. C. 1985: Phase shifter calibration in phaseshifting interferometry. Appl. Opt. 24, 3049–3052

    Google Scholar 

  • Creath, K. 1985: Phase-shifting speckle interferometry. Appl. Opt. 24, 3053–3058

    Google Scholar 

  • Hermann, R. 1936: Wärmeübergang bei freier Strömung am waagerechten Zylinder in zweiatomigen Gasen. Forschg. Ing.-Wes. 7, Forschungsheft 379, 1–24

    Google Scholar 

  • Schmidt, E.; Beckmann, W. 1930: Das Temperatur-und Geschwindigkeitsfeld vor einer Wärme abgebenden senkrechten Platte bei natürlicher Konvektion. Tech. Mech. Thermodyn. 1, 341–349 and 391–406

    Google Scholar 

  • Vest, C. M. 1979: Holographic interferometry. pp. 329–334. New York: Wiley

    Google Scholar 

  • Watt, D. W.; Vest, C. M. 1987: Digital interferometry for flow visualization. Exp. Fluids 5, 401–406

    Google Scholar 

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Lanen, T.A.W.M., Nebbeling, C. & van Ingen, J.L. Digital phase-stepping holographic interferometry in measuring 2-D density fields. Experiments in Fluids 9, 231–235 (1990). https://doi.org/10.1007/BF00190424

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  • DOI: https://doi.org/10.1007/BF00190424

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