Microorganisms such as bacteria use their rotating helical
flagella for propulsion speeds up to tens of tail lengths per
second. The mechanism can be utilized for controlled pumping
of liquids in microchannels. In this study, we aim to analyze the
effects of control parameters such as axial span between helical
rounds (wavelength), angular velocity of rotations (frequency),
and the radius of the helix (amplitude) on the maximum timeaveraged
flow rate, maximum head, rate of energy transfer, and
efficiency of the micropump. The analysis is based on
simulations obtained from the three-dimensional timedependent
numerical model of the flow induced by the rotating
spiral inside a rectangular-prism channel. The flow is governed
by Navier-Stokes equations subject to continuity in timevarying
domain due to moving boundaries of the spiral.
Numerical solutions are obtained using a commercial finiteelement
package which uses arbitrary Lagrangian-Eulerian
method for mesh deformations. Results are compared with
asymptotic results obtained from the resistive-force-theory
available in the literature
