Phase-resolving simulation of dense bubble clusters under periodic shear


Phase-resolving simulation of dense bubble clusters under periodic shear

Heitkam, S.; Fröhlich, J.

The paper studies the response of a cluster of bubbles to osmotic pressure, and steady and oscillatory shearing by resolved numerical simulations. In contrast to other investigations, the movement of the interstitial fluid is fully resolved. To that end, an immersed-boundary method is employed, yielding the trajectory of each bubble and the flow and pressure field of the fluid. Additionally, a physically motivated collision model ensures realistic bubble interactions. Furthermore, a suitable numerical configuration is proposed which allows imposing osmotic pressure and shear in a way that integrates well into the simulation without generating artefacts. This method allows for the realistic investigation of the compression of bubbles across the jamming limit, demonstrating the influence of the inertia of the interstitial fluid. Applying oscillatory shearing with varying osmotic pressure, shear stress and frequency, the occurrence of shear bands is demonstrated and the influence on rheometric measurements is discussed.

Keywords: Bubbles; Simulation; Rheology; Foam

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Permalink: https://www.hzdr.de/publications/Publ-28168
Publ.-Id: 28168