This paper was presented at the 4th Micro and Nano Flows Conference (MNF2014), which was held at University College, London, UK. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute, ASME Press, LCN London Centre for Nanotechnology, UCL University College London, UCL Engineering, the International NanoScience Community, www.nanopaprika.eu.A generic microfluidic system composed by two single chamber valveless micropumps connected
to a simple T-type channel intersection is examined numerically. The characteristics of a feasible valveless
micropump have been used in the design, where efficient mixing is produced due to the pulsating flow
generated by the micropumps. The advantages of using time pulsing inlet flows for enhancing mixing in
channels have been harnessed through the activation of intrinsic characteristics of the pumps required to
achieve the periodic flows. A parametric study is carried out on this microfluidic system using Computational Fluids Dynamics (CFD)on a design space defined by a Design-of-Experiments (DOE) technique. The frequency f and the phase difference f of the periodic fluid velocities (operation parameters) and the angle q formed by the inlet channels at the intersection (geometric parameter) are used as design parameters, whereas mixing quality, pressure drop and maximum shear strain rate in the channel are the performance parameters. The study identifies design features for which the pressure drop and shear strain are reduced whereas the mixing quality is increased. The proposed microfluidic system achieves high mixing quality with performance parameters that enable manipulation of biological fluids in microchannels
