The main purpose of this study is to investigate numerically the thermal performance of a parabolic trough solar collector’s absorber tube that contains a novel kind of inserts with the objective to improve the heat transfer between the heat transfer fluid and the absorber tube. In the first part of this paper, the diameter and the length of the cylindrical inserts are investigated based on Finite Volume Method and Monte Carlo Ray Tracing method for Reynolds number ranges from 2 . 36 ∙ 10 4 to 7 . 09 ∙ 10 4 . In the second part, the eccentricity of the cylindrical inserts is investigated under the same operating conditions. The Therminol ®VP1 is the HTF that used in this investigation intermediate fluid. The numerical simulation indicates that the perturbators enhance the thermal behavior of receiver and reduces the absorber tube’s temperature difference.

The current study focuses on the thermal distribution in the boundary layer of a wedge with a variable surface temperature. The governing equations of MHD flow for variable wall temperature conditions can be converted to ODE by using similarity solutions, and the Hartmann number (Ha) from 1 to 3 can be solved via the colocation method. This method’s results are compared to those of the numerical method, and it is then evaluated and validated. As the angle or Ha increases, the width of the hydrodynamic boundary layer decreases, and the slope of the boundary layer increases, increasing the coefficient of friction on the surface. The results are obtained for variable wall temperature (n), Prandtl number (Pr) and Eckert number (Ec), where they are 0.5≤n≤1.5, 0.5≤Pr≤5, and 0.001≤Ec≤0.002, and at a certain angle. It is observed that when Ha, Pr, and n increase, the thermal boundary layer grows faster than before; thus, thickness decreases and the Nusselt number (Nu) rises; however, as the Ec adds, the Nu decreases on the wall.