标题：Assessment of the Thermo-Hydraulic Efficiency of an Indoor-Designed Jet Impingement Solar Thermal Collector Roughened with Single Discrete Arc-Shaped Ribs
摘要：This study illustrates the impact of single discrete arc-shaped ribs (SDASR)-type artificial roughness on the performance of a jet impingement solar thermal collector (JISTC). The impact of parametric variations of SDASR on the Nusselt number (Nusdr), friction factor (fsdr), and thermohydraulic performance (ηsdr) is examined. The spacer length (Ssdr) of the SDASR was changed from 0 mm to 300 mm in stages of 100 mm during the experiment. The fixed parameters of the SDASR were a relative discrete distance Dd/Lv of 0.67, relative discrete width gw/Hr of 0.87, relative rib height Hr/H of 0.047, relative rib pitch Pr/H of 1.7, angle of an arc αsdr of 60°, jet diameter ratio Dj/Dhy of 0.065, streamwise pitch ratio X/Dhy of 1.72, and spanwise pitch ratio Y/Dhy of 0.82. The Reynolds number Re was altered from 3000 to 19,000. The Nusdr and fsdr of a JISTC with a roughened absorber plate was found to be enhanced by 5.25 and 5.98 times as compared to an STC without artificial roughness. The optimal findings of Nusdr, fsdr, and ηsdr were achieved at Ssdr = 0 mm. The maximum value of the ηsdr obtained at Ssdr = 0 mm was 2.9.
