Hydrophobic wavy tape to augment the parabolic trough solar collector performance

It is expected to use wavy tapes to enhance the efficiency of solar collectors. But the side effect of using these inserts is increased pressure drop. This study presents hydrophobic wavy tape to alleviate the adverse effects of elevated pressure drop. Wavy tapes with different shapes, including fixed and variable wave width and height, were examined experimentally. The impact of the hydrophobicity of the surface of the wavy tape on the thermohydraulic performance of the parabolic trough solar collector was studied. The results showed that increasing both the width and height of the tape enhances the thermal efficiency of the solar collector. To simultaneously address the improvement of pressure drop and thermal efficiency, the performance indicator was defined. It was observed that the wavy tape of variable width and height can lead to a better performance indicator. Also, the hydrophobicity of the surface of the wavy tapes raises their performance indicator by 42%.