Numerical Study on Forced‐Convection Flow Over the Annulus Region With Variable Properties of Fluids

ABSTRACT

The article expounds on forced convective flow over an annular region with an irregular boundary in a diverging channel and on the fluid properties. The nanosized particles are used in the inner nanofluid region and the base fluid in the annulus region. The nonlinear governing equations for the inner and annulus regions are converted into nondimensional partial differential equations using similarity transformations, which are then simplified to linear form by the quasilinearization method. The system of linear equations is then solved using the finite‐difference method. Results are obtained and expressed in terms of velocity, temperature, and concentration profiles, including magnetic and dissipation parameters, the Nusselt number, and skin friction, and are discussed using graphical aids. The findings suggest that the nanofluid region yields significant changes in velocity profiles in the presence of the magnetic parameter (). In the case of temperature profiles, the annulus region has a lower heat‐transfer rate. The diameter of the annulus region has a dominant impact on fluid behavior. Pressure drop and resistance are higher in the annulus region than in the inner region in terms of skin friction. The temperature profile overshoots in the annulus region for viscous dissipation (). In the case of the inner region, the reverse trend is observed; the mass transfer rate () increases by approximately 45% as the Lewis number rises from 1.0 to 2.0 in the inner region. An increase in Lewis number strengthens mass transfer characteristics by lowering mass diffusivity relative to thermal diffusivity, resulting in a thinner concentration boundary layer. As a result, the concentration gradient at the surface steepens, increasing the mass transfer rate.