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arXiv · 2405.02135

Intermittent thermal convection in jammed emulsions

Francesca Pelusi·Andrea Scagliarini·Mauro Sbragaglia·Massimo Bernaschi·Roberto Benzi
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Abstract

We study the process of thermal convection in jammed emulsions with a yield-stress rheology. We find that heat transfer occurs via an intermittent mechanism, whereby intense short-lived convective "heat bursts" are spaced out by long-lasting conductive periods. This behaviour is the result of a sequence of fluidization-rigidity transitions, rooted in a non-trivial interplay between emulsion yield-stress rheology and plastic activity, which we characterize via a statistical analysis of the dynamics at the droplet scale. We also show that droplets' coalescence induced during heat bursts leads to a spatially heterogeneous phase-inversion of the emulsion which eventually supports a sustained convective state.

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Francesca Pelusi, Andrea Scagliarini, Mauro Sbragaglia, Massimo Bernaschi, Roberto Benzi. 2024-05-03. Intermittent thermal convection in jammed emulsions. https://doi.org/10.1103/physrevlett.133.244001

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