Particle and thermo-hydraulic maldistribution of nanofluids in parallel microchannel systems

TL;DR

This study uses computational modeling to analyze nanofluid distribution and heat transfer in microchannel systems, revealing complex particle behavior that impacts cooling efficiency beyond traditional homogeneous fluid assumptions.

Contribution

It introduces a novel concentration maldistribution factor and demonstrates the importance of discrete phase modeling for nanofluids in microchannels.

Findings

Nanofluids cannot be accurately modeled as homogeneous fluids in microchannels.

Particle distribution does not necessarily follow flow patterns, affecting thermal performance.

A mathematical model predicts enhanced cooling due to particle migration phenomena.

Abstract

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.