The Physics Society of Iran Iranian Journal of Physics Research 1682-6957 22 3 2022 11 22 The effect of closed cycle of air flow circulation on the thermal performance of solar air collector The effect of closed cycle of air flow circulation on the thermal performance of solar air collector 51 59 3287 10.47176/ijpr.22.3.21174 FA Djamel Bensahal Laboratory of Mechanic, Faculty of Technology, University of Laghouat, Laghouat (03000), Algeria Ahmed Yousfi Laboratory of Mechanic, Faculty of Technology, University of Laghouat, Laghouat (03000), Algeria Journal Article 2020 12 20 This experimental study aims to investigate the effect of the closed cycle of air circulation on the thermal performance of the solar air collector with attached fins in the site of Laghouat in Algeria, under climatic conditions. Our experimental procedure includes two types of cycles: open cycle and closed cycle. For each cycle, we have considered two tilt angle: 0 and 30 degree. Moreover, the solar collector is oriented in a southerly direction with a definite angle of inclination. The flow rate used in experiment is equal to 0.0129402 m³/s. Then, by comparing the experimental and theoretical results, we observe that the maximum temperature difference between the outlet and inlet air for the open cycle (27 °C, at 14h30) is higher than that of the close cycle (17 °C, at 14h00). The maximum efficiencies obtained for the open cycle for the both configurations were η (30 degrees) = 25.29 % and η (0 degree) = 35.71 % at 4 pm. These values are higher than those of the maximum efficiencies of the closed cycle with η (30 degrees) = 7.86 % at 4 pm and η (0  degree) = 13.31% at 12h00, respectively This experimental study aims to investigate the effect of the closed cycle of air circulation on the thermal performance of the solar air collector with attached fins in the site of Laghouat in Algeria, under climatic conditions. Our experimental procedure includes two types of cycles: open cycle and closed cycle. For each cycle, we have considered two tilt angle: 0 and 30 degree. Moreover, the solar collector is oriented in a southerly direction with a definite angle of inclination. The flow rate used in experiment is equal to 0.0129402 m³/s. Then, by comparing the experimental and theoretical results, we observe that the maximum temperature difference between the outlet and inlet air for the open cycle (27 °C, at 14h30) is higher than that of the close cycle (17 °C, at 14h00). The maximum efficiencies obtained for the open cycle for the both configurations were η (30 degrees) = 25.29 % and η (0 degree) = 35.71 % at 4 pm. These values are higher than those of the maximum efficiencies of the closed cycle with η (30 degrees) = 7.86 % at 4 pm and η (0  degree) = 13.31% at 12h00, respectively https://ijpr.iut.ac.ir/article_3287_946e3ece1fc8b24bd656449d88eca941.pdf