Imperial College London
Alternate

Dr John Craske

Faculty of Engineering, Department 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

@article{Craske:2021:10.1017/jfm.2021.435,
author = {Craske, J},
doi = {10.1017/jfm.2021.435},
journal = {Journal of Fluid Mechanics},
pages = {1--29},
title = {Decomposition of available potential energy for networks of connected volumes},
url = {http://dx.doi.org/10.1017/jfm.2021.435},
volume = {920},
year = {2021}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - A decomposition of available potential energy is derived for Boussinesq fluid flow in networks of connected control volumes. The two constituent parts of the decomposition are positive definite and therefore meaningful representations of available energy. The first (inner) part accounts for available potential energy that is intrinsic to each control volume, while the second (outer) part accounts for the context provided by the larger parent volume to which each smaller control volume belongs. While the intended application casts the control volumes as connected rooms in a building, the formulation can be applied to any domain that is partitioned by either physical boundaries or abstract zones and can be invoked recursively to clarify the hierarchical dependence of available potential energy on scale and context. By deriving budgets for the decomposition, two ways in which available potential energy can be redistributed between its inner and outer parts are identified. The first accounts for an apparent generation of available potential energy due to diapycnal mixing within a control volume that is constrained by removable boundaries. The second involves the reversible conversion between inner and outer parts that occurs when mass or heat is transported between control volumes and accounts for the concomitant change in context. Analytical expressions are derived for the hierarchy of contributions to available potential energy in an example involving three connected spaces, before budgets for the decomposition from a direct numerical simulation are analysed. Finally, the dependence of mixing efficiency on remote regions that was identified by Davies Wykes et al. (J. Fluid Mech., vol. 781, 2015, pp. 261–275) is revisited to demonstrate the precise way in which the proposed decomposition quantifies context.
AU  - Craske,J
DO  - 10.1017/jfm.2021.435
EP  - 29
PY  - 2021///
SN  - 0022-1120
SP  - 1
TI  - Decomposition of available potential energy for networks of connected volumes
T2  - Journal of Fluid Mechanics
UR  - http://dx.doi.org/10.1017/jfm.2021.435
UR  - https://www.cambridge.org/core/journals/journal-of-fluid-mechanics/article/decomposition-of-available-potential-energy-for-networks-of-connected-volumes/C09EAF3205BC3552DFE4A583B366E186
UR  - http://hdl.handle.net/10044/1/89724
VL  - 920
ER  -
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