Enhanced thermal efficiency in parabolic trough solar collectors using ternary hybrid nanofluids and twisted tape inserts: a numerical study

Abstract Parabolic trough collectors often face efficiency losses due to limited heat transfer and high pressure drops. This study numerically investigates the combined impact of ternary hybrid nanofluids and twisted tape inserts on thermal performance under turbulent flow (Reynolds number from 10,000 to 20,000). Using ANSYS Fluent, 15 models were developed with varying twisted tape configurations (0–4 inserts) and ternary hybrid nanofluid concentrations (0–24 wt%), assuming single-phase nanofluid flow under a 600 kW/m² non-uniform heat flux. Results show that the maximum Nusselt number improvement (44.3%) and friction factor enhancement (62.3%) occur in the model using 4 twisted tapes and 24 wt% ternary hybrid nanofluid. Also, the performance evaluation criterion reaches 1.219 using the optimal model with 2 twisted tapes and 24 wt% ternary hybrid nanofluids. These findings suggest that combining nanofluids and passive inserts can substantially enhance the thermal performance of parabolic trough collectors, guiding the design of next-generation solar receivers.