Absorber tube in parabolic trough concentrating systems is located at the location of the focal line and a fluid
passes through it, the temperature of which increases due to receiving heat from sunlight. The more heat the fluid
can absorb from the concentrated solar energy, the better the performance of the system. Since turbulators can be
used in the absorber tube for this purpose, a lot of experimental and numerical research have been done on the
performance of parabolic trough collectors equipped with various turbulators. In this study, the most important
findings of these studies are presented and then, Nusselt number ratio, mean friction factor ratio, and thermal–
hydraulic performance evaluation criterion are used to compare the hydrothermal performance of the
systems. After reviewing previous researches and identifying advantages and disadvantages of each turbulator, a
novel parabolic trough collector equipped with a turbulator is introduced and its hydrothermal performance is
evaluated through simulation. The outcomes revealed that the ribbed absorber tube and the concentric rod insert
are the most optimum turbulators. In addition, the parabolic trough collector equipped with a combination of
corrugated channel and obstacle has a much better hydrothermal performance than the collectors using each of
these turbulators separately.