1 research outputs found
Optimal Strokes of Low Reynolds Number Linked-Sphere Swimmers
Optimal gait design is important for micro-organisms and micro-robots that
propel themselves in a fluid environment in the absence of external force or
torque. The simplest models of shape changes are those that comprise a series
of linked-spheres that can change their separation and their sizes. We examine
the dynamics of three existing linked-sphere types of modeling swimmers in low
Reynolds number Newtonian fluids using asymptotic analysis, and obtain their
optimal swimming strokes by solving the Euler-Lagrange equation using the
shooting method. The numerical results reveal that (1) with the minimal 2
degrees of freedom in shape deformations, the model swimmer adopting the mixed
shape deformation modes strategy is more efficient than those with a
single-mode of shape deformation modes, and (2) the swimming efficiency mostly
decreases as the number of spheres increases, indicating that more degrees of
freedom in shape deformations might not be a good strategy in optimal gait
design in low Reynolds number locomotion