ABSTRACT Enhancing the thermal efficiency of parabolic solar collectors is still a challenging issue. In this study, two strategies including using nanofluid and a rotary turbulator are applied to ameliorate thermal efficiency. Here, graphene oxide/SiO2 nanofluids are fabricated in different concentrations and their thermophysical properties are measured. Subsequently, a numerical model is carried out to study the influence of applying nanofluid and the rotary turbulator on thermal efficiency. The results indicate that using nanofluid leads to a 9% increase in thermal efficiency and adding the turbulator enhances thermal efficiency by more than 20%. Although hydraulic analysis reveals the Performance Evaluation Criteria remains in an acceptable range, the friction factor and Nusselt number increase by the addition of nanoparticles to the basefluid.