Abstract:

In this study, we examine the effects of various shapes of nanoparticles in a steady flow of hybrid nanofluids between two stretchable rotating disks. The steady flow of hybrid nanofluids with transformer oil as the base fluid and Fe₃O₄+TiO₂ as the hybrid nanofluid is considered. Several shapes of Fe₃O₄+TiO₂ hybrid nanofluids, including sphere, brick, blade, cylinder, and platelet, are studied. Every shape exists in the same volume of a nanoparticle. The leading equations (partial differential equations (PDEs)) are transformed to the nonlinear ordinary differential equations (ODEs) with the help of similarity transformations. The system of equations takes the form of ODEs depending on the boundary conditions, whose solutions are computed numerically by the bvp4c MATLAB solver. The outputs are compared with the previous findings, and an intriguing pattern is discovered, such that the tangential velocity is increased for the rotation parameter, while it is decreased by the stretching values because of the lower disk. For the reaction rate parameter, the concentration boundary layer becomes shorter, and the activation energy component increases the rate at which mass transfers come to the higher disk but have the opposite effect on the bottom disk. The ranges of various parameters taken into account are Pr = 6.2, Re = 2, M = 1.0, ϕ₁ = ϕ₂ = 0.03, K = 0.5, S = -0.1, Br = 0.3, Sc = 2.0, α₁ = 0.2, γ = 0.1, E_n = 2.0, and q = 1.0, and the rotation factor K is within the range of 0 to 1.

Key words: transformer oil, Brinkman number, skin friction coefficient, double rotating disk, Nusselt number, Sherwood number