The focus of this paper is on the characteristics (in terms of pressure loss and heat transfer) of an isothermal turbulent flow inside the absorber of a solar receiver. After a short description of the receiver and the power plant, we will focus on a certain kind of internal geometry: straight fins. A preliminary study based on correlations will be presented. This study allows us to define the optimal configuration of the absorber. Following that, a more detailed analysis - based on 3-D simulations - of an elementary component of the absorber is made in order to understand the physical phenomena taking place in the channels. Two simulation methods, Reynolds Averaged Navier-Stokes (RANS) and Large Eddy Simulation (LES) are used in order to determine precisely the characteristics of the flow inside the absorber. A comparison between all the models is carried out. It appears that the correlations do not exactly match the simulation results for all types of flow. However, even if the correlations cannot accurately describe the physics of the flow for this type of flow, the results of the simulations show that the studied solar absorber geometry allows reaching the targeted outlet temperature with an acceptable pressure drop. (C) 2013 Elsevier Ltd. All rights reserved.