The growing demand for heat exchange in industrial processes has resulted in an influential increase in the utilization of solar collectors across various industries. This work analyzes the parabolic trough collector (PTC) thermal efficiency outfitted with star-shaped separation tapes numerically, aiming to enhance the heat transfer surface area and ameliorate radial heat transfer. The use of two hybrid nanofluids, Syltherm800/CuO-MgO and Syltherm800/Al2O3-MWCNT, with varying solid nanoparticle volume fractions in the base fluid Syltherm800 oil, distinguishes this research from other studies. The geometrical modeling of the collector was carried out using SolidWorks, and the computational fluid dynamics (CFD) simulation was performed in ANSYS Fluent 19.2, employing the finite volume method (FVM). The Reynolds number (Re) range is Re = 10000–25000, within which the turbulent flow regime is considered. The numerical model is validated versus empirical data from an available reference in the turbulent flow regime, demonstrating acceptable accuracy. The determinations of this research are presented in two distinct parts. The first part examines the working fluid type influence, and the second part investigates the working fluid volume concentration impact on the presented heat exchanger per formance. The results indicate that the maximum thermal efficiency is attained with the Syltherm800/CuO-MgO hybrid nanofluid. Furthermore, the highest thermal performance for this nanofluid is attained at Re = 25000 and φ1 = φ2 = 0.7. As the volume concentration increases, the pressure drop difference between the nanofluids also increases. Across all studied Reynolds numbers, the thermal efficiency for volume fractions of 0.3,0.5, and 0.7 is greater than one, implying that the utilization of the Syltherm800/CuO-MgO hybrid nanofluid with these three concentrations is economically viable compared to pure Syltherm 800.
