Computational fluid dynamics and experimental investigation of dimple tube solar trough heater using silver nanofluids

Abstract

Growing demand for high-efficiency solar thermal systems requires increased heat-transfer augmentation in parabolic trough-based water-heating applications. Low thermal conductivity in conventional working fluids reduces energy capture and unstable outlet temperatures. A unique Silver-Nanofluid Thermo-Hydraulic Multimodel (SNT-THM) technique addresses these constraints. The method combines a tailored silver nanofluid, optimized swirl-induced turbulence, and a hybrid computational fluid dynamics-based multimodel for thermo-hydraulic prediction and validation. Results indicate a 25%–40% increase in heat-transfer ratio, improved temperature uniformity, enhanced thermal efficiency, and acceptable pressure drops, demonstrating the feasibility of SNT-THM for next-generation high-performance solar water-heating collectors.