Combined influence of fluctuations in the temperature and stretching velocity of the sheet on MHD flow of Cu-water nanofluid through rotating porous medium with cubic auto-catalysis chemical reaction

This work is devoted to examine the three dimensional flow of Cu-water nanofluid over a vertical oscillatory stretchable sheet having fluctuating temperature in comparison to the constant free stream temperature. The sheet embedded in porous medium is assumed to be rotating in a direction normal to its plane and is considered to be lying in a strong transverse magnetic field. The novel concepts of homogeneous-heterogeneous chemical reaction and thermal radiation are also incorporated while developing unsteady boundary layer equations governing the nanofluid flow. After exploiting appropriate transformations, the equations are reduced to dimensionless form which in turn are solved by employing an explicit finite difference scheme (EFDS). To obtain accurate solutions, stability and convergence conditions are also derived. Further, a comparative analysis is presented for the two cases namely fluctuating nanofluid flow (FNF) and non-fluctuating nanofluid flow (NFNF), and impacts of involved physical parameters on velocity distribution, temperature distribution and concentration fields are explored through graphs, and discussed in detail. The quantities of physical interest like surface shear stress, and heat and mass transfer rates are also computed for pertinent parameters and discussed with the help of tables. An interesting and novel result which we found is that oscillation can be utilized in delaying the boundary layer separation and moreover, in controlling the heat and mass transfer processes.