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Effects of polymer additives in the bulk of turbulent thermal convection

Published online by Cambridge University Press:  04 November 2015

Yi-Chao Xie ,
Shi-Di Huang ,
Denis Funfschilling ,
Xiao-Ming Li ,
Rui Ni  and
Ke-Qing Xia
Yi-Chao Xie
Affiliation:
Department of Physics, The Chinese University of Hong Kong, Shatin, Hong Kong, China
Shi-Di Huang
Affiliation:
Department of Physics, The Chinese University of Hong Kong, Shatin, Hong Kong, China
Denis Funfschilling
Affiliation:
LRGP, Lorraine University, CNRS, 1 rue Grandville B.P. 20451, F-54001 Nancy, France
Xiao-Ming Li
Affiliation:
Department of Physics, The Chinese University of Hong Kong, Shatin, Hong Kong, China
Rui Ni
Affiliation:
Department of Physics, The Chinese University of Hong Kong, Shatin, Hong Kong, China
Ke-Qing Xia*
Affiliation:
Department of Physics, The Chinese University of Hong Kong, Shatin, Hong Kong, China
*
†Email address for correspondence: [email protected]
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Abstract

We present experimental evidence that a minute amount of polymer additives can significantly enhance heat transport in the bulk region of turbulent thermal convection. The effects of polymer additives are found to be the enhancement of coherent heat fluxes and suppression of incoherent heat fluxes. The enhanced heat transport is associated with the increased coherency of thermal plumes, as a result of the suppression of small-scale turbulent fluctuations by polymers. The incoherent heat flux, arising from turbulent background fluctuations, makes no net contribution to heat transport. The fact that polymer additives can increase the coherency of thermal plumes is supported by the measurements of a number of local quantities, such as the extracted plume amplitude and width, the velocity autocorrelation functions and the velocity–temperature cross-correlation coefficient. The results from local measurements also suggest the existence of a threshold value for the polymer concentration, only above which significant modification of the plume coherent properties and enhancement of the local heat flux can be observed. Estimation of the plume emission rate suggests a stabilization of the thermal boundary layer by polymer additives.

JFM classification

Convection: Plumes/thermals Non-Newtonian Flows: Polymers
Type
Rapids
Information
Journal of Fluid Mechanics , Volume 784 , 10 December 2015 , R3
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Copyright
© 2015 Cambridge University Press 

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Footnotes

‡

Present address: Department of Mechanical and Nuclear Engineering, Pennsylvania State University, State College, PA 16802-1412, USA.

References

Ahlers, G., Grossmann, S. & Lohse, D. 2009 Heat transfer and large-scale dynamics in turbulent Rayleigh–Bénard convection. Rev. Mod. Phys. 81, 503–537.Google Scholar
Ahlers, G. & Nikolaenko, A. 2010 Effect of a polymer additive on heat transport in turbulent Rayleigh–Bénard convection. Phys. Rev. Lett. 104, 034503.CrossRefGoogle ScholarPubMed
Benzi, R., Ching, E. S. C. & De Angelis, E. 2010 Effect of polymer additives on heat transport in turbulent thermal convection. Phys. Rev. Lett. 104, 024502.CrossRefGoogle ScholarPubMed
Benzi, R., Ching, E. S. C. & Chu, V. W. S. 2012 Heat transport by laminar boundary layer flow with polymers. J. Fluid Mech. 696, 330–344.Google Scholar
Boffetta, G., Mazzino, A., Musacchio, S. & Vozella, L. 2010 Polymer heat transport enhancement in thermal convection: the case of Rayleigh–Taylor turbulence. Phys. Rev. Lett. 104, 184501.Google Scholar
Calzavarini, E., Lohse, D., Toschi, F. & Tripiccione, R. 2005 Rayleigh and Prandtl number scaling in the bulk of Rayleigh–Bénard turbulence. Phys. Fluids 17, 055107.Google Scholar
Chillá, F. & Schumacher, J. 2012 New perspectives in turbulent Rayleigh–Bénard convection. Eur. Phys. J. E 35, 58.Google Scholar
Ching, E. S. C., Guo, H., Shang, X.-D., Tong, P. & Xia, K.-Q. 2004 Extraction of plumes in turbulent thermal convection. Phys. Rev. Lett. 93, 124501.Google Scholar
Crawford, A. M., Mordant, N., Xu, H. & Bodenschatz, E. 2008 Fluid acceleration in the bulk of turbulent dilute polymer solutions. New J. Phys. 10, 123015.CrossRefGoogle Scholar
Huang, S.-D., Kaczorowski, M., Ni, R. & Xia, K.-Q. 2013 Confinement-induced heat-transport enhancement in turbulent thermal convection. Phys. Rev. Lett. 111, 104501.Google Scholar
Lohse, D. & Toschi, F. 2003 Ultimate state of thermal convection. Phys. Rev. Lett. 90, 034502.Google Scholar
Lohse, D. & Xia, K.-Q. 2010 Small-scale properties of turbulent Rayleigh–Bénard convection. Annu. Rev. Fluid Mech. 42, 335–364.Google Scholar
Malkus, W. V. R. 1954 The heat transport and spectrum of thermal turbulence. Proc. R. Soc. Lond. A 225, 196–212.Google Scholar
Ouellette, N. T., Xu, H. & Bodenschatz, E. 2009 Bulk turbulence in dilute polymer solutions. J. Fluid Mech. 629, 375–385.CrossRefGoogle Scholar
Procaccia, I., L’vov, V. S. & Benzi, R. 2008 Theory of drag reduction by polymers in wall-bounded turbulence. Rev. Mod. Phys. 80, 225–247.CrossRefGoogle Scholar
Qiu, X.-L., Xia, K.-Q. & Tong, P. 2005 Experimental study of velocity boundary layer near a rough conducting surface in turbulent natural convection. J. Turbul. 6, N30.CrossRefGoogle Scholar
Rubinstein, M. & Colby, R. H. 2003 Polymer Physics. Oxford University Press.Google Scholar
Shang, X.-D., Qiu, X.-L., Tong, P. & Xia, K.-Q. 2003 Measured local heat transport in turbulent Rayleigh–Bénard convection. Phys. Rev. Lett. 90, 074501.Google Scholar
Shang, X.-D., Qiu, X.-L., Tong, P. & Xia, K.-Q. 2004 Measurements of the local convective heat flux in turbulent Rayleigh–Bénard convection. Phys. Rev. E 70, 026308.CrossRefGoogle ScholarPubMed
Sun, C., Cheung, Y.-H. & Xia, K.-Q. 2008 Experimental studies of the viscous boundary layer properties in turbulent Rayleigh–Bénard convection. J. Fluid Mech. 605, 79–113.CrossRefGoogle Scholar
Toms, B. A. 1948 Some observations on the flow of linear polymer solutions through straight tubes at large Reynolds numbers. In Proceedings of the First International Rheological Congress, vol. 2, pp. 135–141.Google Scholar
Traore, B., Castelain, C. & Burghelea, T. 2015 Efficient heat transfer in a regime of elastic turbulence. J. Non-Newtonian Fluid Mech. 223, 62–76.CrossRefGoogle Scholar
Wei, P., Chan, T.-S., Ni, R., Zhao, X.-Z. & Xia, K.-Q. 2014 Heat transport properties of plates with smooth and rough surfaces in turbulent thermal convection. J. Fluid Mech. 740, 28–46.Google Scholar
Wei, P., Ni, R. & Xia, K.-Q. 2012 Enhanced and reduced heat transport in turbulent thermal convection with polymer additives. Phys. Rev. E 86, 016325.Google Scholar
Xi, H.-D., Bodenschatz, E. & Xu, H. 2013 Elastic energy flux by flexible polymers in fluid turbulence. Phys. Rev. Lett. 111, 024501.Google ScholarPubMed
Xia, K.-Q. 2013 Current trends and future directions in turbulent thermal convection. Theor. Appl. Mech. Lett. 3, 052001.CrossRefGoogle Scholar
Xia, K.-Q., Sun, C. & Zhou, S.-Q. 2003 Particle image velocimetry measurement of the velocity field in turbulent thermal convection. Phys. Rev. E 68, 066303.CrossRefGoogle ScholarPubMed
Zhou, Q., Stevens, R. J. A. M., Sugiyama, K., Grossmann, S., Lohse, D. & Xia, K.-Q. 2010 Prandtl–Blasius temperature and velocity boundary-layer profiles in turbulent Rayleigh–Bénard convection. J. Fluid Mech. 664, 297–312.Google Scholar
Zhou, Q. & Xia, K.-Q. 2010 Measured instantaneous viscous boundary layer in turbulent Rayleigh–Bénard convection. Phys. Rev. Lett. 104, 104301.Google Scholar
Zimm, B. H. 1956 Dynamics of polymer molecules in dilute solution: viscoelasticity, flow birefringence and dielectric loss. J. Chem. Phys. 24, 269–278.Google Scholar