Akademik Veri Yönetim Sistemi
Journal of Thermal Analysis and Calorimetry, cilt.148, sa.17, ss.9013-9025, 2023 (SCI-Expanded)
The solar air heater (SAH) is a flow device of various forms. The presence of rib turbulators is one of the basic characteristics of heat transfer changes. Two-dimensional numerical simulation of heat transfer provided by a SAH with inclined ribs at different angles (60°, 90°, 120°, 150°, 180°, and 210°) is investigated to determine the optimum angle of the inclined ribs leading to the maximum qualification of the SAH. The model is validated by comparing computed results with experimental data obtained under the same conditions. A good agreement using the standard k-epsilon model is assigned. Additionally, different Reynolds numbers (from 3800 to 18,000) are used to evaluate its effects on Nusselt number and friction factor, providing insights into the optimal operating conditions of the SAH. The design of inclined ribs significantly affects the thermal performance of SAHs. Results indicate that the thermal performance is improved when using an angle of the ribs greater than 90°. Specifically, an angle of 180° for the ribs was found to provide the optimum thermal performance. Results also demonstrate that the optimum angle is 180° for a Reynolds number of 18,000 where the Nusselt number and the friction factor are improved by 25% and 93% respectively, compared to its value obtained for an angle of 90°. The findings revealed the effect of increasing the angle of the inclined ribs on the thermal hydraulic performance parameter that the optimal angle of 180° enhances convection heat transfer and improves the efficiency of the system. The variation of the Reynolds numbers can impact the performance of the SAH, providing useful insights for the optimal operation.