Hostname: page-component-78c5997874-ndw9j Total loading time: 0 Render date: 2024-11-17T21:35:41.195Z Has data issue: false hasContentIssue false

Multi-point local temperature measurements inside the conducting plates in turbulent thermal convection

Published online by Cambridge University Press:  14 October 2021

Chao Sun
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

Abstract

An experimental study of local temperature statistics in turbulent thermal convection is presented. The emissions of plumes and plume clusters are detected by an array of thermistors embedded in the top and bottom plates of a 1 m diameter convection cell. We found that the product STST of the temperature skewness ST and the skewness of the temperature time derivative ST from the embedded thermistors may be used as a measure of the intensity of plume emissions and that STST exhibits a pattern that corresponds well to the orientation of the large-scale circulation in the convecting flow. This is despite the fact that the temperature distribution across the plates is highly uniform, as indicated by the mean temperature of the embedded thermistors. By comparing the spatial distributions of STST and of the RMS temperature σ, we further find that the maximum temperature fluctuations take place in regions dominated by plume mixing instead of regions of plume emission. It is also found that temperature fluctuations inside the conducting plates have the same statistical and scaling properties as those in the cell centre.

Type
Research Article
Copyright
Copyright © Cambridge University Press 2007

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Belmonte, A. & Libchaber, A. 1996 Thermal signature of plumes in turbulent convection: The skewness of the derivative. Phys. Rev. E 53, 48934898.10.1103/PhysRevE.53.4893CrossRefGoogle ScholarPubMed
Bershadskii, A., Niemela, J. J., Praskovsky, A. & Sreenivasan, K. R. 2004 ¡°Clusterization¡± and intermittency of temperature fluctuations in turbulent convection. Phys. Rev. E 69, 056314.10.1103/PhysRevE.69.056314CrossRefGoogle Scholar
Brown, E., Nikolaenko, A. & Ahlers, G. 2005a Reorientation of the large-scale circulation in turbulent Rayleigh-Bénard convection. Phys. Rev. Lett. 95, 084503.10.1103/PhysRevLett.95.084503CrossRefGoogle ScholarPubMed
Brown, E., Nikolaenko, A., Funfschilling, D. & Ahlers, G. 2005b Heat transport in turbulent Rayleigh-Bénard convection: Effect of finite top- and bottom-plate conductivity. Phys. Fluids 17, 075108.10.1063/1.1964987CrossRefGoogle Scholar
Castaing, B., Gnuaratne, G., Heslot, F, Kadanoff, L., Libchaber, A., Thomae, S., Wu, X. Z., Zaleski, S. & Zanetti, G. 1989 Scaling of hard thermal turbulence in Rayleigh-Bénard turbulent convection. J. Fluid Mech. 204, 130.10.1017/S0022112089001643CrossRefGoogle Scholar
Chaumat, S., Castaing, B. & Chillà, F. 2002 Rayleigh-Bénard cells: Influence of the plate properties. Advances in Turbulence IX: Proc. 9th European Turbulence Conference (ed. Castro, I. P., Hancock, P. E. & Thomas, T. G.). CIMNE, Barcelona.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, 124501.10.1103/PhysRevLett.93.124501CrossRefGoogle ScholarPubMed
Cioni, S., Ciliberto, S. & Sommeria, J. 1997 Strongly turbulent Rayleigh-Bénard convection in mercury: comparison with results at moderate Prandtl number. J. Fluid Mech. 335, 111140.10.1017/S0022112096004491CrossRefGoogle Scholar
Funfschilling, D. & Ahlers, G. 2004 Plume motion and large-scale circulation in a cylindrical Rayleigh-Bénard cell. Phys. Rev. Lett. 92, 194502.10.1103/PhysRevLett.92.194502CrossRefGoogle Scholar
Grossmann, S. & Lohse, D. 2000 Scaling in thermal convection: A unifying theory. J. Fluid Mech. 407, 2756.10.1017/S0022112099007545CrossRefGoogle Scholar
Hunt, J. C. R., Vrieling, A. J., Nieuwstadt, F. T. M. & Fernando, H. J. S. 2003 The influence of the thermal diffusivity of the lower boundary on eddy motion in convection. J. Fluid Mech. 491, 183205.10.1017/S0022112003005482CrossRefGoogle Scholar
Krishnamurti, R. & Howard, L. N. 1981 Large-scale flow generation in turbulent convection. Proc. Natl Acad. 78 (4), 19811985.10.1073/pnas.78.4.1981CrossRefGoogle ScholarPubMed
Lui, S.-L. & Xia, K.-Q. 1998 Spatial structure of the thermal boundary layer in turbulent convection. Phys. Rev. E 57, 54945503.10.1103/PhysRevE.57.5494CrossRefGoogle Scholar
Parodi, A., Hardenberg, J., Passoni, G., Provenzale, A. & Spiegel, E. A. 2004 Clustering of Plumes in Turbulent Convection. Phys. Rev. Lett. 92, 194503.10.1103/PhysRevLett.92.194503CrossRefGoogle ScholarPubMed
Qiu, X.-L. & Tong, P. 2001 Onset of coherent oscillations in turbulent Rayleigh-Bénard convection. Phys. Rev. Lett. 87, 094501.10.1103/PhysRevLett.87.094501CrossRefGoogle ScholarPubMed
Sreenivasan, K. R. & Antonia, R.A. 1977 Skewness of temperature derivatives in turbulent shear flows. Phys. Fluids 20, 19861988.10.1063/1.861828CrossRefGoogle Scholar
Sun, C., Ren, L.-Y., Song, H. & Xia, K.-Q. 2005a Heat transport by turbulent Rayleigh-Bénard convection in 1 m diameter cylindrical cells of widely varying aspect ratio. J. Fluid Mech. 542, 165174.10.1017/S0022112005006610CrossRefGoogle Scholar
Sun, C., Xia, K.-Q. & Tong, P. 2005b Three-dimensional flow structures and dynamics of turbulent thermal convection in a cylindrical cell. Phys. Rev. E 72, 026302.10.1103/PhysRevE.72.026302CrossRefGoogle Scholar
Verzicco, R. 2004 Effects of nonperfect thermal sourses in turbulent thermal convection. Phys. Fluids 16, 19651979.10.1063/1.1723463CrossRefGoogle Scholar
Xi, H.-D., Lam, S. & Xia, K.-Q. 2004 From laminar plumes to organized flows: the onset of large-scale circulation in turbulent thermal convection. J. Fluid Mech. 503, 4756.10.1017/S0022112004008079CrossRefGoogle Scholar
Xi, H.-D., Zhou, Q. & Xia, K.-Q. 2006 Azimuthal motion of the mean wind in turbulent thermal convection. Phys. Rev. E 73, 056312.10.1103/PhysRevE.73.056312CrossRefGoogle ScholarPubMed
Xia, K.-Q. & Lui, S.-L. 1997 Turbulent thermal convection with an obstructed sidewall. Phys. Rev. Lett. 79, 50065009.10.1103/PhysRevLett.79.5006CrossRefGoogle Scholar
Zhou, S.-Q. & Xia, K.-Q. 2002 Plume statistics in thermal turbulence: mixing of an active scalar. Phys. Rev. Lett. 89, 184502.10.1103/PhysRevLett.89.184502CrossRefGoogle ScholarPubMed