Abstract

This study investigates the transient flow of an electrically conducting viscous fluid subjected to a radial magnetic field, 
applied at both the outer surface of the central cylinder and the inner surface of the peripheral cylinder. The energy equa
tion incorporates radiative heat flux effects using the Rosseland diffusion approximation. Numerical solutions are obtained 
via the implicit finite difference method and validated against analytical results derived from the regular perturbation 
method as time approaches the working fluid parameter. The effects of key governing parameters on velocity, tempera
ture distribution, sensitivity, and drag coefficient within the coaxial cylinder are analyzed and presented through tables 
and figures. The findings reveal that the Grashof number is a highly sensitive parameter for skin friction at both cylinder 
surfaces under isothermal and isoflux conditions at 33.336–32.1433% respectively at time, t = 0.2. In contrast, the injec
tion parameter exerts the most significant influence on heat transfer, particularly under isoflux conditions at 45.0233% 
compared to the Isothermal at 39.9477%. These insights enhance the understanding of Magnetohydrodynamics (MHD) 
flow behavior and heat transfer in cylindrical configurations with radiative effects.