Combined Effects of Variable Thermal Conductivity and Electrical Conductivity on Peristaltic Flow of Pseudoplastic Nanofluid in an Inclined Non-Uniform Asymmetric Channel: Applications to Solar Collectors

As conduction, convection, and radiation are fundamental modes of heat emitter and transfer, this paper looks at the influences of temperature-dependent thermal conductivity and thermal radiation on peristaltic flow of pseudoplastic nanofluids in an inclined non-uniform asymmetric channel. Inclined magnetic field is taken into consideration. As the Wiedemann–Franz law in metals, electrical conductivity has identical behavior as that of thermal conductivity; as freely animated evenness, electrons transfer not only electric current but also heat energy. Consequently, electrical conductivity should be depending on the temperature of nanoparticles. The related equations of momentum, mass, and concentration are reformulated using lubrication approximations (i.e., tiny or zero Reynolds number and long wavelength). The resulting system of nonlinear equations is solved semi-numerically with the aid of the parametric ND solve package using mathematica version 11. Results of velocity, temperature, and concentration distributions are obtained in the analytical three-dimensional forms. The streamline graphs are offered in the terminus, which elucidate the trapping bolus phenomenon. As a special case, a comparison is made and signified with the recently published results by Hayat et al. (2016, Soret and Dufour Effects in MHD Peristalsis of Pseudoplastic Nanofluid With Chemical Reaction,” J. Mol. Liq., 220, pp. 693–706). It's found that, the increases in thermal conductivity and electrical conductivity cause an increase in the temperature of nanofluid and the heat transfer rate gets induced so a better absorption of solar energy is gained.