Akademik Veri Yönetim Sistemi
Journal of Thermal Analysis and Calorimetry, 2026 (SCI-Expanded, Scopus)
This study presents a numerical investigation of the thermohydraulic performance of four internal insert configurations Bottom Inserts, Top Inserts, Alternate Inserts, and Disc Inserts integrated within the absorber tube of a parabolic trough collector. The Monte Carlo ray tracing method is employed to generate a realistic non-uniform circumferential heat flux distribution on the absorber outer surface, which is coupled with the Finite Volume Method to solve the governing equations of fluid flow and heat transfer. Therminol® VP-1 is used as the heat transfer fluid, and simulations are conducted over a Reynolds number range of 2.36 × 104 to 7.09 × 104 under turbulent flow conditions. All four insert configurations significantly enhance convective heat transfer relative to the smooth tube, with the Disc Inserts achieving the highest Nusselt number improvement of 263.44% at Re = 7.09 × 104. However, this enhancement comes at the cost of an increased friction factor, at Re = 7.09 × 104, the friction factor of Disc Inserts is approximately 12.1 times that of the smooth tube, compared to ratios of 4.7, 4.0, and 3.9 for Alternate Inserts, Bottom Inserts, and Top Inserts, respectively. Despite this hydraulic penalty, the Performance Evaluation Criterion exceeds unity for all configurations, confirming a net thermohydraulic benefit. In terms of thermal uniformity, the Disc Inserts reduce the circumferential wall temperature gradient by 84.2% (from 122.05 to 19.23K), followed by Alternate Inserts with a 72.7% reduction (33.28K), Bottom Inserts with 68.4% (38.54K), and Top Inserts with 24.9% (91.60K). The maximum wall temperature is also reduced from 698.84K in the smooth tube to 594.22K with Disc Inserts. These results demonstrate that Disc Inserts represent the most effective passive enhancement strategy for PTC absorber tubes, offering superior heat transfer, thermal uniformity, and overall thermohydraulic performance.