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Bounds for internally heated convection with fixed boundary heat flux

Published online by Cambridge University Press:  05 July 2021

Ali Arslan*
Affiliation:
Department of Aeronautics, Imperial College London, LondonSW7 2AZ, UK
Giovanni Fantuzzi
Affiliation:
Department of Aeronautics, Imperial College London, LondonSW7 2AZ, UK
John Craske
Affiliation:
Department of Civil and Environmental Engineering, Imperial College London, LondonSW7 2AZ, UK
Andrew Wynn
Affiliation:
Department of Aeronautics, Imperial College London, LondonSW7 2AZ, UK
*
Email address for correspondence: [email protected]

Abstract

We prove a new rigorous bound for the mean convective heat transport $\langle w T \rangle$, where $w$ and $T$ are the non-dimensional vertical velocity and temperature, in internally heated convection between an insulating lower boundary and an upper boundary with a fixed heat flux. The quantity $\langle wT \rangle$ is equal to half the ratio of convective to conductive vertical heat transport, and also to $\frac 12$ plus the mean temperature difference between the top and bottom boundaries. An analytical application of the background method based on the construction of a quadratic auxiliary function yields $\langle w T \rangle \leq \frac {1}{2}(\frac {1}{2}+ \frac {1}{\sqrt {3}} ) - 1.6552\, {\textit {R}}^{-(1/3)}$ uniformly in the Prandtl number, where R is the non-dimensional control parameter measuring the strength of the internal heating. Numerical optimisation of the auxiliary function suggests that the asymptotic value of this bound and the $-1/3$ exponent are optimal within our bounding framework. This new result halves the best existing (uniform in $ {\textit {R}}$) bound (Goluskin, Internally Heated Convection and Rayleigh–Bénard Convection, Springer, 2016, table 1.2), and its dependence on $ {\textit {R}}$ is consistent with previous conjectures and heuristic scaling arguments. Contrary to physical intuition, however, it does not rule out a mean heat transport larger than $\frac 12$ at high $ {\textit {R}}$, which corresponds to the top boundary being hotter than the bottom one on average.

Type
JFM Rapids
Copyright
© The Author(s), 2021. Published by Cambridge University Press

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References

REFERENCES

Arslan, A., Fantuzzi, G., Craske, J. & Wynn, A. 2021 Bounds on heat transport for convection driven by internal heating. J. Fluid Mech. 919, A15.CrossRefGoogle Scholar
Chernyshenko, S.I. 2017 Relationship between the methods of bounding time averages. arXiv:1704.02475.Google Scholar
Chernyshenko, S.I., Goulart, P.J., Huang, D. & Papachristodoulou, A. 2014 Polynomial sum of squares in fluid dynamics: a review with a look ahead. Philos. Trans. Roy. Soc. A 372 (2020), 20130350.CrossRefGoogle ScholarPubMed
Constantin, P. & Doering, C.R. 1995 Variational bounds on energy dissipation in incompressible flows. II. Channel flow. Phys. Rev. E 51 (4), 31923198.CrossRefGoogle ScholarPubMed
Doering, C.R. & Constantin, P. 1994 Variational bounds on energy dissipation in incompressible flows: shear flow. Phys. Rev. E 49 (5), 40874099.CrossRefGoogle ScholarPubMed
Doering, C.R. & Constantin, P. 1996 Variational bounds on energy dissipation in incompressible flows. III. Convection. Phys. Rev. E 53 (6), 59575981.CrossRefGoogle ScholarPubMed
Doering, C.R. & Tobasco, I. 2019 On the optimal design of wall-to-wall heat transport. Comm. Pure Appl. Math. 72 (11), 23852448.CrossRefGoogle Scholar
Fantuzzi, G., Goluskin, D., Huang, D. & Chernyshenko, S.I. 2016 Bounds for deterministic and stochastic dynamical systems using sum-of-squares optimization. SIAM J. Appl. Dyn. Syst. 15 (4), 19621988.CrossRefGoogle Scholar
Fantuzzi, G., Pershin, A. & Wynn, A. 2018 Bounds on heat transfer for Bénard–Marangoni convection at infinite Prandtl number. J. Fluid Mech. 837, 562596.CrossRefGoogle Scholar
Fantuzzi, G. & Wynn, A. 2015 Construction of an optimal background profile for the Kuramoto–Sivashinsky equation using semidefinite programming. Phys. Lett. A 379 (1-2), 2332.CrossRefGoogle Scholar
Fantuzzi, G. & Wynn, A. 2016 Optimal bounds with semidefinite programming: an application to stress-driven shear flows. Phys. Rev. E 93 (4), 043308.CrossRefGoogle ScholarPubMed
Fantuzzi, G., Wynn, A., Goulart, P.J & Papachristodoulou, A. 2017 Optimization with affine homogeneous quadratic integral inequality constraints. IEEE Trans. Automat. Control 62 (12), 62216236.CrossRefGoogle Scholar
Goluskin, D. 2015 Internally heated convection beneath a poor conductor. J. Fluid Mech. 771, 3656.CrossRefGoogle Scholar
Goluskin, D. 2016 Internally heated convection and Rayleigh–Bénard convection. Springer.CrossRefGoogle Scholar
Goluskin, D. & Fantuzzi, G. 2019 Bounds on mean energy in the Kuramoto–Sivashinsky equation computed using semidefinite programming. Nonlinearity 32 (5), 17051730.CrossRefGoogle Scholar
Goluskin, D. & van der Poel, E.P. 2016 Penetrative internally heated convection in two and three dimensions. J. Fluid Mech. 791, R6.CrossRefGoogle Scholar
Hassanzadeh, P., Chini, G.P. & Doering, C.R. 2014 Wall to wall optimal transport. J. Fluid Mech. 751, 627662.CrossRefGoogle Scholar
Hewitt, J.M., McKenzie, D.P. & Weiss, N.O. 1980 Large aspect ratio cells in two-dimensional thermal convection. Earth Planet. Sci. Lett. 51 (2), 370380.CrossRefGoogle Scholar
Ishiwatari, M., Takehiro, S.-I. & Hayashi, Y.-Y. 1994 The effects of thermal conditions on the cell sizes of two-dimensional convection. J. Fluid Mech. 281, 3350.CrossRefGoogle Scholar
Kiefer, W.S. & Li, Q. 2009 Mantle convection controls the observed lateral variations in lithospheric thickness on present-day mars. Geophys. Res. Lett. 36 (18), L18203.CrossRefGoogle Scholar
Lee, S.D., Lee, J.K. & Suh, K.Y. 2007 Boundary condition dependent natural convection in a rectangular pool with internal heat sources. J. Heat Transfer 129 (5), 679682.CrossRefGoogle Scholar
Lu, L., Doering, C.R. & Busse, F.H. 2004 Bounds on convection driven by internal heating. J. Math. Phys. 45 (7), 29672986.CrossRefGoogle Scholar
Mulyukova, E. & Bercovici, D. 2020 Mantle convection in terrestrial planets. Oxford Research Encyclopedia of Planetary Science.CrossRefGoogle Scholar
Rosa, R. & Temam, R.M. 2020 Optimal minimax bounds for time and ensemble averages of dissipative infinite-dimensional systems with applications to the incompressible Navier–Stokes equations. arXiv:2010.06730.Google Scholar
Schubert, G., Turcotte, D.L. & Olson, P. 2001 Mantle convection in the Earth and planets. Cambridge University Press.CrossRefGoogle Scholar
Spiegel, E.A. 1963 A generalization of the mixing-length theory of turbulent convection. Astrophys. J. 138, 216225.CrossRefGoogle Scholar
Tobasco, I. & Doering, C.R. 2017 Optimal wall-to-wall transport by incompressible flows. Phys. Rev Lett. 118 (26), 264502.CrossRefGoogle ScholarPubMed
Trowbridge, A.J., Melosh, H.J., Steckloff, J.K. & Freed, A.M. 2016 Vigorous convection as the explanation for Pluto's polygonal terrain. Nature 534 (7605), 7981.CrossRefGoogle ScholarPubMed
Wen, B., Goluskin, D. & Doering, C.R. 2020 Steady Rayleigh–Bénard convection between no-slip boundaries. arXiv:2008.08752.CrossRefGoogle Scholar