This paper presents a numerical approach to solving unsteady hybrid nanofluid flow
problems using the overlapping grid multi-domain bivariate spectral simple iteration method
(OMD-BSSIM). The method utilizes the Chebyshev spectral collocation approach to
approximate the derivatives in the overlapping grid of space and non-overlapping grid of time,
which allows for handling the two domains (multi-domain) problem. In this paper, we propose
using the overlapping bivariate spectral method in combination with the simple iteration
method instead of the commonly used quasi-linearization, relaxation, or local linearization
schemes. The governing equations are transformed into a system of nonlinear partial
differential equations using similarity transformations. The OMD-BSSIM is applied to
investigate the heat transfer rate for MHD, unsteady GNP − Fe3O4/H2O, and TiO2 - Fe3O4/H2O hybrid nanofluids flow, with projection angles ranging from 0∘to90∘, representing the influence of different magnetic fields. The numerical solution is obtained using OMDBSSIM implemented in MATLAB. We use R visualization techniques and graphs to analyze the relationship between the skin friction coefficients, local Nusselt number, and Sherwood number of the hybrid nanofluids and some parameters. The results show that the increase in the volume fraction of GNP nanoparticle has a greater effect on the temperature profile than TiO2 nanoparticle. Additionally, notable positive relationships were observed for the rotation parameter, while the stretching parameter had a negative impact on certain outcome measures.
Keywords: Hybrid nanofluid, Overlapping chebyshev spectral collocation, Rotating surface, Simple iteration method.