Impact of Multi-Walled Carbon Nanotube Dimensions on Heat and Momentum Transfer in Miniature Channels

This paper numerically examines the effect of nanoparticle dimensions on heat and momentum transfer in laminar flow within a fully developed region of miniature channels. Velocity boundary conditions are fully developed, heat flux is applied from the upper and lower walls, and the other walls are insulated. Five different shapes of multi-walled carbon nanotubes (MWCNTs) are stabilized in water and ethylene glycol, which serve as the base fluids. These contain volume fractions of 0.25%, 0.50%, and 0.75%, used as working fluids for flow simulation. The study discusses the influence of nanoparticle dimensions (length and external diameter), volume fraction, Reynolds number, and base fluid type on heat transfer. The longer the geometrical shapes of the particles relative to each other, the higher the heat conduction and heat transfer coefficients. Additionally, results show that using water as the base fluid results in less enhancement of heat transfer compared to ethylene glycol. Finally, the study offers insights for selecting suitable nanofluids for simulation and practical applications.