NUMERICAL MODELING OF VISCOUS MHD FLOW INDUCED BY STRETCHING AND ROTATION IN COAXIAL CYLINDERS

In this study, the effect of viscous forces on magnetohydrodynamic (MHD) flow between two coaxial cylinders is investigated, where the inner cylinder undergoes linear axial stretching while the outer cylinder rotates with a constant angular velocity. A first-order slip boundary condition is imposed at the surface of the inner cylinder to account for the possibility of partial slip at the boundary. In addition, viscous dissipation is incorporated into the model to evaluate its contribution to the thermal behavior of the fluid. The governing partial differential equations for mass, momentum, and energy conservation are converted into a dimensionless system of ordinary differential equations by suitable transformations. The resultant equations are solved numerically with an efficient technique, specifically the Legendre Smooth Composite Pseudospectral Method. The influences of key parameters such as the curvature parameter, cylinder gap, magnetic parameter, and slip parameter are presented graphically, demonstrating that increasing the distance between the cylinders leads to higher fluid velocity and temperature levels. Furthermore, the results indicate the existence of a critical gap parameter at which the heat transfer rate reaches its minimum value. This observation provides useful physical insight for the optimal design of rotating cylindrical systems in engineering applications such as cooling devices, rotating machinery, and thermal energy transport systems.