In solar energy conversion and utilization in a parabolic dish collector (PDC), the accurate modeling of the system and also the appropriate selection of adjustable operational parameters, are so important. In this work, a helically baffled cylindrical cavity receiver in a PDC system was studied experimentally and theoretically. For optical and thermal modeling of the system, a novel combining method was used. The real solar flux distribution on the receiver internal walls was obtained by using SolTrace software and then, the real fluxes were employed in ANSYS Fluent software to increase the accuracy of CFD modeling of the system. The model was verified and validated with the experimental data, and a good agreement was observed with a maximum deviation of about 2%. The effect of some geometrical and structural parameters such as receiver aperture distance to the focal point ratio, receiver aspect ratio and system geometrical concentration ratio and also, some operational parameters such as Heat Transfer Fluid (HTF) inlet temperature, mass flow rate and solar irradiation intensity on the thermal performance of the system were investigated. The results show that the optimal selection of the mentioned parameters can enhance the thermal performance of the system up to 65%. (C) 2018 Elsevier Ltd. All rights reserved.