Abstract-Modeling of a compound parabolic collector with bare tubular absorber was performed, regarding its geometrical, optical and thermal features. The developed model was validated via two recent experiments showing accepted agreement with the experimental results. After that we studied the effect of inserting different configurations of twisted tapes in the absorber tube on the thermal efficiency, the pumping power and the thermal performance factor. It was concluded that inserting twisted tapes is much favorable when the flow was laminar rather than being in transition or turbulent regimes.Index Terms-Compound parabolic concentrators, heat transfer enhancement, modeling, swirl flow.