Impact of pseudoplastic and dilatants behavior of Reiner-Philippoff nanofluid on peristaltic motion with heat and mass transfer analysis in a tapered channel

The main goal of this article is to investigate the effects of pseudoplastic, and dilatants behavior of non-Newtonian based nanofluid on peristaltic motion in an asymmetric tapered channel. Buongiorno's nanofluid model is considered for the study to investigate the heat and mass transfer analysis. The Reiner-Philippoff fluid model is considered to depict the non-Newtonian characteristics of the fluid. The Reiner Philippoff fluid model is the most challenging model among other non -Newtonian fluid models in such a way that shear stress and velocity gradient are non-linearly proportional to each other in this model. This model also represents the implicit relation between stress and deformation rate. The governing equations are based on the dispersion model for nanofluid which incorporates the effects of thermophoretic and Brownian diffusions. The governing equations are simplified in the account of the small Reynolds number and long wavelength assumptions. The solution of the equations is retrieved numerically by the help of built in ND-Solve function of MATHEMATICA software. The sound effects of Reiner-Philippoff based nanofluid on the behavior of velocity and temperature profiles of the fluid, streamlines, pressure gradient fields, and concentration of the nanoparticles are discussed thoroughly. The interesting behavior of Reiner-Philippoff fluid for two limiting shear stress cases when shear stress parameter is very small and very large, for which Reiner-Philippoff fluid behaves like a Newtonian fluid, is also verified. It is observed that fluid flow changes its properties from dilatants fluid to Newtonian and from Newtonian to pseudoplastic fluid by varying the Reiner-Philippoff fluid parameter. According to the findings, the temperature graphs rise against higher thermophoretic diffusion and Brownian motion parameters and falls with higher Prandtl number. Further, the impacts of all the significant parameters are investigated briefly by mathematically as well as graphically.