16 papers
Oscillatory shear flows and a new 2D self-sustaining process
Theo A. Lewy, Rich R. Kerswell
A new self-sustaining process (SSP) is identified in an oscillating spatially-homogeneous shear flow using a nonlinear Kelvin mode model. This SSP consists of energetic spanwise-in…
Non-normal weakly nonlinear analysis: asymptotic consistency and non-universality
Matthew McCormack, Gregory P. Chini, Rich R. Kerswell
Non-normality can induce large transient growth in linearly stable systems. Determining whether this growth triggers a transition in the underlying nonlinear system, however, requi…
Significant heat transfer enhancement via polymer additives in two-dimensional sheared convection
Guanhan Li, Lu Zhu, Rich. R. Kerswell
Heat dissipation is critical in modern engineering systems. Polymer additives offer a potential route to improve fluid-based cooling. Here, we study elasticity-enhanced heat transf…
Localised Arrowheads: The building blocks of elastic turbulence in rectilinear, sheared polymer flows
Theo A. Lewy, Rich R. Kerswell
Pressure-driven flow of a dilute polymer solution has been numerically observed to possess a form of elastic turbulence which is organised around the interactions of localised vers…
Elastic turbulence in highly entangled polymers and wormlike micelles
Theo A. Lewy, Suzanne M. Fielding, Peter D. Olmsted +1
We show theoretically that an initially homogeneous planar Couette flow of a concentrated polymeric fluid is linearly unstable to the growth of two-dimensional (2D) perturbations,…
On the essential structure of exact traveling-wave solutions in viscoelastic flow
Lu Zhu, Rich. R. Kerswell
We examine elastic travelling-wave (`arrowhead') solutions in a viscoelastic, unidirectionally body-forced flow, focusing on their existence and morphological changes as the Weisse…