Improvement of the thermal and hydraulic performance of parabolic trough collectors using hybrid nanofluids and novel turbulators with holes and ribs

In this study, innovative methods to improve the thermal efficiency and hydraulic performance of parabolic trough collectors are presented by locating different turbulators in the tube and adding hybrid nanofluids with volume percentage of 0, 2, and 4. The Eulerian scheme and Phase Coupled Simple method are employed for hybrid nanofluids. A novel turbulator with holes and ribs is employed to improve the thermal and hydraulic efficiency of parabolic trough collectors. Two types of turbulators with three values of turn = 0.3, 0.5, and 0.7 are used in these simulations. In the first turbulator, about 50.5% increase in thermal efficiency is achieved while the volume fraction of nanoparticles, Reynolds number, and turn are minimum. In maximum and minimum conditions, an increase in the mean Nusselt number for the second type of turbulator is equal to 44.6%. At maximum conditions, the value of the heat index number in the second type of turbulator is about 3.3% higher than that in the first one. This research suggests an appropriate perspective to increase the thermal and hydraulic efficiency of parabolic trough collectors by adding novel turbulators and employing hybrid nanofluids.