Particle and thermohydraulic maldistribution of nanofluids in parallel microchannel systems

Abstract

Fluidic m aldistribution in microscale multichannel devices requires deep understanding to achiev e optimized flow and heat transfer characteristics . A thorough computational study has been performed to understand the concentration and thermo – hydraulic maldistribution of nanofluid s in parallel microchannel system s using an Eulerian – Lagrangian twin phase model. The study reveal s 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 parameter s . To comprehend the distribution of the particulate phase , a nove l 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 f rom homogeneous models . Particle maldistributio n 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 pha se approach in modelling nanofluid thermo – hydraulics and sheds insight on behavior of nanofluids in complex flow domains.