Imperial College London

Dr John Craske

Faculty of EngineeringDepartment of Civil and Environmental Engineering

Senior Lecturer
 
 
 
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Contact

 

+44 (0)20 7594 9702john.craske07 Website

 
 
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Assistant

 

Miss Rebecca Naessens +44 (0)20 7594 5990

 
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Location

 

328BSkempton BuildingSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@unpublished{Arslan:2022,
author = {Arslan, A and Fantuzzi, G and Craske, J and Wynn, A},
publisher = {arXiv},
title = {Rigorous scaling laws for internally heated convection at infinite Prandtl number},
url = {https://arxiv.org/abs/2205.03175},
year = {2022}
}

RIS format (EndNote, RefMan)

TY  - UNPB
AB - New bounds are proven on the mean vertical convective heat transport, wT¯¯¯¯¯¯¯¯¯¯¯, for uniform internally heated (IH) convection in the limit of infinite Prandtl number. For fluid in a horizontally-periodic layer between isothermal boundaries, we show that wT¯¯¯¯¯¯¯¯¯¯¯≤12−cR−2, where R is a nondimensional `flux' Rayleigh number quantifying the strength of internal heating and c=216. Then, wT¯¯¯¯¯¯¯¯¯¯¯=0 corresponds to vertical heat transport by conduction alone, while wT¯¯¯¯¯¯¯¯¯¯¯>0 represents the enhancement of vertical heat transport upwards due to convective motion. If, instead, the lower boundary is a thermal insulator, then we obtain wT¯¯¯¯¯¯¯¯¯¯¯≤12−cR−4, with c≈0.0107. This result implies that the Nusselt number Nu, defined as the ratio of the total-to-conductive heat transport, satisfies NuR4. Both bounds are obtained by combining the background method with a minimum principle for the fluid's temperature and with Hardy--Rellich inequalities to exploit the link between the vertical velocity and temperature. In both cases, power-law dependence on R improves the previously best-known bounds, which, although valid at both infinite and finite Prandtl numbers, approach the uniform bound exponentially with R.
AU - Arslan,A
AU - Fantuzzi,G
AU - Craske,J
AU - Wynn,A
PB - arXiv
PY - 2022///
TI - Rigorous scaling laws for internally heated convection at infinite Prandtl number
UR - https://arxiv.org/abs/2205.03175
UR - http://hdl.handle.net/10044/1/97430
ER -