Physics of Fluids - Publications

Heat transport enhancement in confined Rayleigh-Benard convection feels the shape of the container

Open Access
Europhysics Letters 135(2), 24004 (2021)

Authors

	Robert Hartmann
	Richard Stevens
	Roberto Verzicco
	Detlef Lohse

BibTeΧ

@article{2021,
	doi = {10.1209/0295-5075/ac19ed},
	url = {https://doi.org/10.1209/0295-5075/ac19ed},
	year = 2021,
	month = {jul},
	publisher = {{IOP} Publishing},
	volume = {135},
	number = {2},
	pages = {24004},
	author = {Robert Hartmann and Kai Leong Chong and Richard J. A. M. Stevens and Roberto Verzicco and Detlef Lohse},
	title = {Heat transport enhancement in confined Rayleigh-B{\'{e}}nard convection feels the shape of the container
		                  (a)},

abstract = {Moderate spatial confinement enhances the heat transfer in turbulent Rayleigh-B√©nard (RB) convection (Chong K. L. et al., Phys. Rev. Lett., 115 (2015) 264503). Here, by performing direct numerical simulations, we answer the question how the shape of the RB cell affects this enhancement. We compare three different geometries: a box with rectangular base (i.e., stronger confined in one horizontal direction), a box with square base (i.e., equally confined in both horizontal directions), and a cylinder (i.e., symmetrically confined in the radial direction). In all cases the confinement can be described by the same confinement parameter , given as height-over-width aspect ratio. The explored parameter range is , for the Rayleigh number, and a Prandtl number of . We find that both the optimal confinement parameter for maximal heat transfer and the actual heat transfer enhancement strongly depend on the cell geometry. The differences can be explained by the formation of different vertically coherent flow structures within the specific geometries. The enhancement is largest in the cylindrical cell, owing to the formation of a domain-spanning flow structure at the optimal confinement parameter .}

}