A study of convective nanofluid flow over a rough slender cylinder under the influence of magnetic field and species diffusion

The present work explores the analysis of magnetohydrodynamics nonlinear mixed conv ective nanofluid flow over a vertical slender cylinder in the presence of surface roughness. The application of the present study can be found in the process of coating wires. In fact, during such a process, thin wires in the slender cylinder need to be cooled, and also heat and mass transfer rates need to be controlled through nanofluid and liquid hydrogen to yield better results. By employing nonsimilar transformations, the partial differential equations governing the flow problem are reduced to dimensionless equations. Furthermore, the Quasilinearization technique and implicit finite difference scheme are used to solve the dimensionless governing equations. The novelty of the analysis is the impacts of surface roughness, diffusion of liquid hydrogen, and the presence of nonlinear mixed convective flow over a slender cylinder. The numerical results reveal that the energy transport strength and surface drag coefficient enhance with the roughness parameter values. The nanoparticle volume fraction profile reduces, while nanoparticle Sherwood number enhances with increasing values of velocity ratio parameter. The presence of nanoparticles in the conventional fluid diminishes the energy transfer value significantly for both smooth and rough surfaces. The velocity of the fluid enhances with increasing values of the mixed convection parameter. Due to surface roughness ((Formula presented.) ≠ 0), sinusoidal variations of the drag are observed along the length of the cylinder in comparison to smooth surface case ((Formula presented.) = 0). The friction between the fluid and the wall rises for a rough surface because pockets of fluid are formed in the cavities due to surface asperities.