7 papers
A transition to elasto-viscoplastic turbulence in inertialess channel flow?
James D. Shemilt, Neil J. Balmforth, Duncan R. Hewitt
We conduct 2D numerical simulations employing a widely used constitutive law for elasto-viscoplastic fluids to show that linear instability leads to spatio-temporal complexity in i…
Start-up and inertialess instability of elasto-viscoplastic channel flow
James D. Shemilt, Neil J. Balmforth, Duncan R. Hewitt
An exploration is presented of the start-up and linear stability of pressure-driven channel flow of an elasto-viscoplastic fluid described by Saramito's constitutive law. Streamwis…
Rayleigh-Plateau instability of an elasto-viscoplastic filament
James D. Shemilt, Neil J. Balmforth
A slender-thread model is used to explore the Rayleigh-Plateau instability of a filament of elasto-viscoplastic fluid. Without elasticity, a finite yield stress suppresses any line…
Coalescence of Printed Yield Stress Filaments in Direct Ink Writing
Hugo L. França, Daniël Tieman, James D. Shemilt +2
In direct ink writing (DIW), neighbouring filaments of yield-stress inks are deposited side-by-side and are expected to merge into smooth, mechanically robust structures. Unlike Ne…
Air-driven dynamics of viscoplastic liquid layers
James D. Shemilt, Neil J. Balmforth, Duncan R. Hewitt
Airway clearance by coughing is a key mechanism for mucus transport, particularly in obstructive lung diseases associated with altered mucus rheology. We investigate the dynamics o…
Viscoplasticity can stabilise liquid collar motion on vertical cylinders
James D. Shemilt, Alice B. Thompson, Alex Horsley +2
Liquid films coating vertical cylinders can form annular liquid collars which translate downwards under gravity. We investigate the dynamics of a thin viscoplastic liquid film coat…