Hybrid Nanofluid Flow Over a Cylindrical Surface with the Double Stratification Effects

Abstract

The present problem studies hybrid nanofluid (HNF) flow along a cylindrical surface, incorporating the effects of double stratification and heat generation. The boundary layer model is reduced to a system of ordinary differential equations (ODEs) by introducing dimensionless variables, which is then computed numerically using the bvp4c routine in MATLAB. The Al₂O₃-Cu/water HNF was used, combining two types of solid nanoparticles, namely, alumina (Al₂O₃) and copper (Cu), and water as the base fluid. For some physical parameters, it is discovered that dual solutions are feasible, where the critical points of the solution occur at the lowest suction strength  and in the shrinking region . By comparing the Al₂O₃–H₂O nanofluidwith Al₂O₃-Cu/H₂O HNF, increasing the volume fraction of hybrid nanoparticles enhances both dynamic viscosity and surface shear stress. Moreover, it is examined that skin friction and the heat and mass transfer rates at the surface are higher for a cylinder than for a flat plate. Finally, the results found that between the two solutions, the first solution maintains physical stability throughout temporal evolution.