CFD analysis of Al2O3-syltherm oil Nanofluid on parabolic trough solar collector with a new flange-shaped turbulator model

In this paper, in order to improve the performance of a linear parabolic collector, the thermal effects of using Al2O3-syltherm oil nanofluid with different concentrations and new flange-shaped turbulators are investigated. The simulation was performed by ANSYS-FLUENT-18.2 commercial software using Realizable k-epsilon two-equation turbulence model. In accordance with the results, it was realized that increasing the volume fraction of nanoparticles (to 5%) and number of turbulators causes the heat transfer coefficient (h) of the fluid to elevate and ultimately the uniform temperature is created in the absorber. For instance, at a flow rate of 4.5kg/s and an inlet temperature of 350 K, the value of h increases by about 8.5 % by changing the number of turbulators from 10 to 15 sets. On the other hand, the results indicate that by changing the arrangement of the turbulators, the heat transfer efficiency of the collector can be increased by 5 % for 350 K, 3.5 % for 450 K and 1% for 550 K inlet temperature. (C) 2022 The Author(s). Published by Elsevier Ltd on behalf of The Chinese Society of Theoretical and Applied Mechanics.