Experimental and CFD analysis of dimple tube parabolic trough solar collector (PTSC) with TiO2 nanofluids

Recently, parabolic trough solar collector (PTSC) efficiency enhancement with nanoparticle concentrations has been identified as a potential research area. In this research, the performance of PTSC with dimple tube with TiO 2 /DI–H 2 O (De-Ionized Water) nanofluid has been analysed using computational fluid dynamics (CFD). The size of the nanoparticle was in the range of 10–15 nm. Different volume concentrations of the nanoparticles in the range of 0.1–0.5%, in steps of 0.1%, were chosen to prepare the nanofluids to carry out the experiments. Experimental and CFD analysis is compared to TiO 2 nanofluid with water (base fluid) at varying mass flow rates (0.5, 1.0, 1.5, 2.0, 2.5 and 3.0 kg min −1 ) in a turbulent flow system using Dimples tube. Furthermore, PTSC parametric values were determined from test results such as friction factor, uncertainty analysis, Reynolds number, solar collector efficiency, Nusselt Number, and Convective heat transfer coefficient. In comparison, the convective heat transfer coefficient of the TiO 2 nanofluids with the base fluid is increased to 34.25% with the dimples tube. The highest performance increase in PTSC with a mass flow rate of 2.5 kg min −1 and 0.3% volume concentration gives overall optimized results in absolute energy absorption, gradient temperature, and efficiency of the solar water heater. The nanofluid’s output index is 2.42 with a 0.3% mass flow rate and a concentration of 1.5 kg min −1 . The PTSC with TiO 2 nanofluid has a maximum overall efficiency of 34.25%, which is 11% higher than the overall efficiency of the base fluid. At a mass flow rate of 3.0 kg min −1 and 0.5% volume concentration, the pressure drop was increased by about 5.68% compared to the mass flow rate of 2.5 kg min −1 .