OICC Press International Journal of Nano Dimension 2228-5059 16 4 2025 05 17 Optimizing thermal efficiency: A Study on parabolic trough solar collector performance with nanofluids and fin designs 10.57647/j.ijnd.2025.1604.31 EN Mostafa Jamali Mechanical Engineering Department, Hamedan University of Technology, Hamedan, Iran Najmeh Hajialigol Mechanical Engineering Department, Hamedan University of Technology, Hamedan, Iran Journal Article 2025 05 17 This study comprehensively explores the application of thermal nanofluids in enhancing the performance of solar parabolic trough collectors through advanced computational modeling techniques. Specifically, the research employs the Large Eddy Simulation (LES) model to investigate heat transfer dynamics, focusing on the interplay between fluid flow characteristics and thermal energy distribution. The analysis examines the influence of varying porous fin heights on the flow structure and heat transfer behavior under a wide range of Reynolds numbers (40,000–450,000) and a fixed Prandtl number of 0.7. Key results indicate that increasing the height of the porous fins significantly improves the overall heat transfer efficiency, as evidenced by an enhancement in the Nusselt number. Additionally, the findings reveal a corresponding increase in the tube friction coefficient, which is essential for understanding the trade-offs between thermal performance and flow resistance. These insights underscore the potential of optimized fin geometries and nanofluid applications in advancing the efficiency of solar thermal power systems.