Heat transfer of viscous fluid in a vertical channel sandwiched between nanofluid porous zones

Mixed convection in vertical parallel channels is analyzed with the viscous fluid sandwiched between nanofluids within porous material filled in a vertical channel. The concept of single-phase transport of nanofluids is employed to define the nanofluid flow and heat transfer and the Darcy approach is incorporated to describe the circulation within the porous material. Formulated ordinary differential equations which are non-linear and coupled along with the corresponding boundary and interface conditions are solved by the regular perturbation method. The main objective is to investigate the effects of the Grashof and Brinkman numbers, solid volume fraction, porous parameter on the velocity and temperature fields. Results are shown in the graphical and tabular form. The physical characteristics governing the flow such as skin friction and rate of heat transfer are also investigated considering five different materials of nanoparticles.