Non-newtonian 3D ciliary fluid flow in a semi-infinite domain

This paper was presented at the 3rd Micro and Nano Flows Conference (MNF2011), which was held at the Makedonia Palace Hotel, Thessaloniki in Greece. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, Aristotle University of Thessaloniki, University of Thessaly, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute.Continuing our previous investigations in ciliary fluid transportation (Isvoranu et al., 2010) our present paper looks into the matter of non-newtonian fluid flow. Naturally, in constant properties fluids (newtonian fluids) ciliary transportation is based on a non-symmetric actuation mechanism meaning different geometrical configuration of the cilium during the active and passive stroke. Artificial cilia can mimick this behaviour through asymmetric magnetic actuation as discused in (Isvoranu et. al., 2008). What happens when fluid properties (eg. viscosity) are not constant throughout a beating cycle? Such situation is expected to be encountered when dealing with biological fluids like saliva, for example. In the case of a shear-thinning fluid, like the above mentioned one, the motion can also become asymetric due to deformation rate dependent viscosity that ultimately leads to different time scales of the forward and backward strokes. In the present paper we are investigating a 3D flow generated by an array of cilia embedded in a non-newtonian fluid whose viscosity is characterized by a power low shear rate dependency. The same magnetic actuation mechanism is considered