Comparative Thermal Aspects of Copper and Copper–Ferro Oxide Nanoparticles With <scp>10W40</scp> Engine Oil Base Fluid: Applications to Thermal Management Systems

ABSTRACT Advanced thermal management systems in automotive and energy sectors demand high‐performance cooling fluids capable of withstanding intense thermal loads. The integration of copper and copper–ferro oxide nanoparticles in engine oil offers a promising route to enhance heat dissipation, minimize energy loss, and ensure operational stability in magneto‐thermal environments. This study presents a detailed thermal and flow analysis of a magnetohydrodynamics (MHD) couple stress hybrid nanofluid containing copper (Cu) and copper–ferrite (Cu‐Fe 3 O 4 ) nanoparticles suspended in an engine oil (10W40C) base fluid. The model incorporates the effects of thermal radiation, internal heat generation, and the Cattaneo–Christov heat flux theory to capture non‐Fourier heat conduction behavior. The fluid is assumed to exhibit couple stress characteristics, suitable for simulating microstructural effects in lubricating and thermal processing systems. A truncated system containing the dimensionless parameters has been attained. The numerical simulations task against this system is complied with the help of the shooting method. A comparative investigation is carried out between mono nanofluid (Cu/engine oil) and hybrid nanoparticle ([Cu‐Fe 3 O 4 ]/engine oil) nanofluids to assess their thermal performance. It has been observed that relaxation time effects play a novel role to control the heat transfer phenomenon. The hybrid nanofluid significantly enhances heat transfer rates compared to the mono nanofluid. Furthermore, the concentration profile declined due to the Schmidt number and concentration relaxation parameter. These findings offer useful insights for advanced thermal management technologies, particularly in automotive and energy‐related applications.