Electrothermal transport of magnetic (SWCNT) suspensions in microchannels and cilia for solar energy

Abstract

This study aims to evaluate the electrothermal and hydrodynamic transport properties of an electrically conductive nanofluid containing single-walled carbon nanotubes (SWCNTs) within a microchannel with wavy walls, with the goal of enhancing thermal performance efficiency in solar energy systems. The developed mathematical model is based on formulating the governing equations of motion, momentum, energy, and concentration, under the assumptions of long wavelength and low Reynolds number consistent with the nature of laminar microfluidic flows. The methodology included the use of perturbation techniques to derive approximate analytical solutions for the nonlinear energy equation, and to derive precise mathematical formulations for velocity distribution, pressure gradient, pressure increase, flow function, as well as temperature and concentration fields. Numerical and graphical analyses were conducted using the MATHEMATICA software to verify the impact of governing physical parameters on fluid response and heat transfer, with outputs represented through two-dimensional and three-dimensional plots. The results revealed a significant improvement in heat transfer rates when integrating SWCNT nanoparticles, along with enhanced mixing and fluid rotation mechanisms due to the ciliary's peristaltic motion, with a critical impact of physical variables on the phenomenon of entrapment and pressure and temperature distributions. These results demonstrate the suitability of SWCNT-based nanofluids as highly efficient operating media in micro heat exchangers, providing valuable theoretical insights for the development of sustainable heat management and renewable energy technologies.