Investigating thermal radiation on thin films of Casson Cu-Ni-Al ₂ O ₃ /water nanofluids for enhanced solar thermal performance

Heat transfer enhancement is inevitable in solar thermal systems which harness solar energy to generate heat. Integration of nanomaterials in such systems particularly like Al 2 O 3 –Cu–Ni with water base can enhance their efficacy. Bearing this idea, the present model deals with nanofluids comprising aluminum oxide, copper, and nickel nanoparticles dispersed in water to improve heat absorption and transfer within the system, contributing to increased overall performance and effectiveness of solar thermal systems. Thus, the study focuses on investigating the heat exchange properties in the context of a flow within the boundary layer of a thin liquid film that is trihybrid on a stretched sheet – quite a significant topic. The aim is to assess the heat behavior of a thin liquid layer in the presence of heat radiation over a stretched sheet of porous medium containing a non-Newtonian fluid (Casson). By applying suitable similarity transformations, the governing equations of the boundary layer constitute a system of ordinary differential equations, which can be solved with the use of a boundary value problem solver. Moreover, the study provides a comparative examination of velocity and temperature profiles for the base fluid, nanofluid, hybrid nanofluid, and trihybrid nanofluid. The investigation’s key findings indicate that the heat exchange properties of trihybrid nanofluids surpass those of hybrid and regular nanofluids. Energy enhancement is lower in non-Newtonian Casson fluid than Newtonian flow. The presence of radiation and unsteadiness improvises the Nusselt number, physically this energy transfer improvement assists to higher solar collector efficacy; converts that energy to usable heat. Practical applications include improving the efficiency of solar collectors, optimizing industrial cooling systems, and enhancing thermal coatings in microelectronics. These findings provide crucial insights into the development of next-generation energy-efficient thermal systems.