Effects of Fins Base Rounding on Heat Transfer Characteristics of Absorber Tube of Parabolic Trough Collector

Abstract In this study, the heat transfer characteristics of an improved absorber tube parabolic trough solar collector LS-2 are investigated using ANSYS software. Oil syltherm 800 type is used as a fluid. Three types tubes tested; first smooth and others finned tubes. One rough cases rectangular cross-section fins with rounding at fin base other does not have base. Simulations performed thickness variations 2, 4 6 mm. The lengths change 5, 10, 15, 20 25 radii 3 mm angles between 45° 90°. Wide range operating parameters considered, such inlet fluid temperatures (300:600 K), flow rate (6:24 m /h) direct normal irradiance (500:1000 W/m 2 ). thermal efficiency, Nusselt number enhancement index calculated under different conditions. results show that round edge radius higher than sharp ( R = 0 mm) by about 10.74% considered length nearly 25.6% 5 At mm, 7.8% fin. angle 25-mm length, for sharp-edged 1.644 1.532, respectively. When temperature increased from 300 to 600 K, value 14.57%; 12 m3/h, decreased 11.63%. 1.265 1.359 varied 500 700 .