Enhancing synthesized engine oil thermal performance through the use of tri-hybrid nanofluids over a bi-directed sheet with Coriolis force

Abstract

Synthetic engine oil offers excellent protection against wear, withstands high temperatures, and maintains its viscosity under various operating conditions. It also enhances oxidative stability and reduces sludge buildup, leading to longer engine life and improved performance. To optimize these benefits, incorporating specific nanoparticles into the synthetic oil may be advantageous. This study investigates the emulsification of three types of nanoparticles-aluminum oxide $(\mathrm{A}{\mathrm{l}}_2{\mathrm{O}}_3)$ , gold $(\mathrm{Au})$ , and graphene oxide $\mathrm{GO}$ -suspended in synthetic oil. The physical insights gained are translated into mathematical equations that describe fluid motion and thermal sensitivity. This dynamical system is simplified into a set of single-variable differential equations, making the analysis more manageable. The dynamical equations are solved numerically using an efficient Spectral Chebyshev Collocation Method (SCCM). The findings indicate that the presence of nanoparticles significantly increases the rate of heat transfer. The shape of the nanoparticles influences thermal performance; platelet-shaped nanoparticles demonstrate superior thermal properties compared to spherical and cylindrical shapes. For a specific Eckman number $(\Omega =0.5)$ , skin friction increases by 141.6% from mono to hybrid nanofluids, and by 83.9% from hybrid to tri-hybrid nanofluids. Within a thermal Biot number range of $[0.1,0.2]$ , the Nusselt number is enhanced by 97.6%, 97.0%, and 96.2%, respectively. Furthermore, the Darcy effect shows opposing behavior at primary and secondary velocities, while thermal convection is improved near the wall as the Biot number increases.