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A novel method to create high density stratification with matching refractive index for optical flow investigations

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Abstract

Turbulent mixing in stratified environments represents a challenging task in experimental turbulence research, especially when large density gradients are desired. When optical measurement techniques like particle image velocimetry (PIV) are applied to stratified liquids, it is common practice to combine two aqueous solutions with different density but equal refractive index, to suppress particle image deflections. While refractive image matching (RIM) has been developed in the late 1970s, the achieved limit of 4% density ratio was not rivalled up to day. In the present work, we report a methodology, based on the behavior of excess properties and their change in a multicomponent system while mixing, that allows RIM for solutions with higher density differences. The methodology is then successfully demonstrated using a ternary combination of water, isopropanol and glycerol, for which RIM in presence of a density ratio of 8.6% has been achieved. Qualitative PIV results of a turbulent buoyant jet with 8.6% density ratio are shown.

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References

  • Adrian RJ, Westerweel J (2011) Particle image velocimetry. Cambridge University Press, Cambridge

    MATH  Google Scholar 

  • Alahyari A, Longmire EK (1994) Particle image velocimetry in a variable density flow: application to a dynamically evolving microburst. Exp Fluids 17:434–440

    Article  Google Scholar 

  • Anwar A, Tariq M (2007) Deviations in refractive index parameters and applicability of mixing rules in binary mixtures of benzene + 1,2-dichloroethane at different temperatures. J Chem Eng Com 195(1):43–56

    Article  Google Scholar 

  • Augier P, Billant P, Negretti M, Chomaz J-M (2014) Experimental study of stratified turbulence forced with columnar dipoles. Phys Fluids 26:046603

    Article  Google Scholar 

  • Bos WJT (2014) On the anisotropy of the turbulent passive scalar in the presence of a mean scalar gradient. J Fluid Mech 744:38–64

    Article  MathSciNet  MATH  Google Scholar 

  • Brocos P, Pinerio A, Bravo R, Amigo A (2003) Refractive indices, molar volumes and molar refractions of binary liquid mixtures: concepts and correlations. Chem Phys 5:550–557

    Google Scholar 

  • Daviero GJ, Roberts PJW, Maile K (2001) Refractive index matching in large-scale stratified experiments. Exp Fluids 31:119–126

    Article  Google Scholar 

  • Garcia B, Alcalde R, Aparicio S, Leal JM (2002) The N-methylpyrrolidone–(C1–C10) alkan-1-ols solvent systems. Phys Chem 4:1170–1177

    Google Scholar 

  • Hannoun IA (1985) Matching the refractive index in density stratified flows. Tech Memo 85-1, WK Keck Laboratory of Hydraulics and Water Resources, California Institute of Technology

  • McDougall TJ (1979) On the elimination of refractive-index variations in turbulent density-stratified liquid flows. J Fluid Mech 93:83–96

    Article  Google Scholar 

  • Paladino D, Andreani M, Zboray R, Dreier J (2012) Toward CFD-grade database addressing LWR containment phenomena. Nucl Eng Dsgn 253:331–342

    Article  Google Scholar 

  • Petrov V, Manera A (2011). Validation of STAR-CCM+ for buoyancy driven mixing in a PWR reactor pressure vessel. In: Proc. of 14th int. topical meeting on nuclear reactor thermal-hydraulics (NURETH-14), Toronto, Canada, September 25–30

  • Riley JJ, De Bruyn Kops SM (2003) Dynamics of turbulence strongly influenced by buoyancy. Phys Fluids 15:2047–2059

    Article  MathSciNet  MATH  Google Scholar 

  • Touriño A, Hervello M, Moreno V, Marino G, Iglesias M (2004) Changes of refractive indices in ternary mixtures containing chlorobenzene + n-hexane + (n-heptane or n-octane) at 298.15 K. J Serbian Chem Soc 69(6):461–475

    Article  Google Scholar 

  • Xiang X, Madison TJ, Sellappan P, Spedding GR (2015) The turbulent wake of a towed grid in a stratified fluid. J Fluid Mech 775:149–177

    Article  MathSciNet  Google Scholar 

  • Yahya M, Saghir MZ (2015) Prediction and experimental measurement of refractive index in ternary hydrocarbon mixtures. J Chem Eng Data 60(8):2329–2342

    Article  Google Scholar 

Download references

Acknowledgements

We are indebted to colleagues at the Experimental and Computational Multiphase Flow Group of University of Michigan for many helpful discussions as well as assistance with various aspects of the experiments. The work was made possible by the generous support of DOE NEUP under Grant no 14-6552.

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Authors and Affiliations

  1. Department of Nuclear Engineering and Radiological Sciences, University of Michigan-Ann Arbor, 2355 Bonisteel Blvd, Ann Arbor, MI, 48109, USA

    Benedikt Krohn, Annalisa Manera & Victor Petrov

Authors
  1. Benedikt Krohn
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  2. Annalisa Manera
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  3. Victor Petrov
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Corresponding author

Correspondence to Benedikt Krohn.

Appendix

Appendix

See Table 2.

Table 2 Refractive indices, density, excess refractive indices and excess density on mixing H2O–glycerol–isopropanol at atmospheric pressure and 298.15 °C
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Krohn, B., Manera, A. & Petrov, V. A novel method to create high density stratification with matching refractive index for optical flow investigations. Exp Fluids 59, 66 (2018). https://doi.org/10.1007/s00348-018-2522-3

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  • DOI: https://doi.org/10.1007/s00348-018-2522-3

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