University of Bath
Lecturer in Applied Mathematics & 1851 Research Fellow
bjw43@bath.ac.uk
University College London
Honorary Lecturer
benjamin.walker@ucl.ac.uk
If we take a minimal model of a microswimmer and include the effects of rapid side-to-side yawing, does the prediction of the model change? Here, we find out through a simple multiple-scales analysis. Image: the effective hydrodynamic shapes of yawing spheroids.
Suppose we have a swimmer that moves by rapidly changing its shape in the plane of a shear flow. Here, we show that, on average, the shape-deforming swimmer undergoes the classical orbit dynamics studied by G. B. Jeffery a century ago. Image: an example shape-changing swimmer being rotated by a background flow.
Given a simple model of a swimmer being carried by the flow in a pipe, can we deduce its long-term behaviour? Here, we avoid numerical simulation and analytically determine the eventual behaviour of the swimmer through the computation of a single swimmer-dependent constant. Image: closed trajectories in semi-periodic phase-space (angle-position).
When we use the simplest microswimmer models to develop intuition for complex, rapidly evolving swimmers, do we have to be careful with our choice of effective parameters? Here, through minimally complex examples and simple multi-timescale analysis, we see that we must be careful even when only seeking qualitative agreement. Image: phase portrait of the interaction of two freely rotating dipoles (angle-angle).
Exploration of the role of solid mechanics in biology, from influencing the growth of tumours to controlling the development of vascular networks.
Efficient simulation of elastohydrodynamics in 2D and 3D, exploring the role and regulation of active moments in eukaryotic flagella, in addition to the responses of filaments to flow.
Investigation into the low Reynolds number swimming of flagellates, such as the boundary response of large-bodied Leishmania and the interactions between nearby spermatozoa.
Automated processing and identification of flagella from videomicroscopy, enabling population-level waveform analysis without requiring costly researcher input. Publication and ImageJ code for flagella capture freely available here.
Incorporation of non-uniform body shapes and curvatures into slender-body theories via asymptotic methods, enabling simple and rapid flow field computation and further theoretical study using regularised singularities.