Significance of thermal radiation and suction/injection on flow and heat transfer of various nanofluids along expandable stretching horizontal cylinder

This work investigates the significance of thermal radiation and suction/injection on the flow and heat transfer problem of various nanofluids along an expandable horizontal cylinder. Glass fiber production, wire drawings, and the plastics industry are just a few of the numerous industrial applications for the problem. Equations of boundary layer fluid flow, including all relevant parameters like the unsteadiness parameter, the thermal radiation parameter, and the suction/injection parameter, will be used to present the mathematical model of the issue. Profiles of fluid velocity and temperature varying with various parameters are obtained numerically by solving the system of ODE and its boundary conditions using the Legendre-collocation method after a suitable similarity transformation. Comparing the obtained results with those already published in certain specific cases validates the proposed numerical method. Deriving a semianalytical solution highlights the innovative aspect of the study. Also, the study innovation is improved by the fact that the nonlinear radiative heat flux is not linearized, and the cylinder’s radius is changing over time. Investigations are conducted into how the nanoparticles concentration, the suction/injection velocity, the thermal radiation, and the expansion of the cylinder’s radius affect the velocity and the temperature of nanofluid in addition to the shear stress and the heat flux of the cylinder’s surface. It is found that the use of a nanofluid as a cooling medium instead of a conventional fluid leads to increasing both surface strength and hardness suggesting that the best fraction of nanoparticles is between 10 and 20 percent. The $\mathrm{Al}_{2} \mathrm{O}_{3}$ nanoparticles are found to be most effective at increasing surface hardness and strength, while Cu nanoparticles are most effective at increasing the cooling rate.