  Fluidic maldistribution in microscale multichannel devices requires deep
understanding to achieve optimized flow and heat transfer characteristics. A
thorough computational study has been performed to understand the concentration
and thermohydraulic maldistribution of nanofluids in parallel microchannel
systems using an Eulerian Lagrangian twin phase model. The study reveals that
nanofluids cannot be treated as homogeneous single phase fluids in such complex
flow domains and effective property models fail drastically to predict the
performance parameters. To comprehend the distribution of the particulate
phase, a novel concentration maldistribution factor has been proposed. It has
been observed that distribution of particles need not essentially follow the
flow pattern, leading to higher thermal performance than expected from
homogeneous models. Particle maldistribution has been conclusively shown to be
due to various migration and diffusive phenomena like Stokesian drag, Brownian
motion, thermophoretic drift, etc. The implications of particle distribution on
the cooling performance have been illustrated and smart fluid effects (reduced
magnitude of maximum temperature) have been observed and a mathematical model
to predict the enhanced cooling performance in such flow geometries has been
proposed. The article presents lucidly the effectiveness of discrete phase
approach in modelling nanofluid thermohydraulics and sheds insight on behavior
of nanofluids in complex flow domains.
