Multiobjective optimization of free convection through a nonuniform cabinet filled with porous media

In the current study, multiobjective optimization and numerical simulation were used to evaluate free convection through a nonuniform cabinet, which has several technical applications, such as cooling techniques, solar air collectors, and heat sinks. The new aspect of the current study is to compute the maximum free convection within an irregular L-shaped cavity filled with porous media using both computational analysis and response surface methodology (RSM). Moreover, the impacts of constant coefficients, such as aspect ratios of the horizontal (AR_h), vertical (AR_v), and Darcy numbers (Da) on the Nusselt number (Nu_ave), Nusselt number maximization (NNM), the temperature of the surface (Ts), and entropy (S) are studied and discussed to evaluate their effect on the thermal performance. The results showed that when Da, AR_h, and AR_v increase, Nu_ave improves while the Ts and S decline and the largest desirability is achieved at AR_h = 0.9, AR_v = 0.9, and Da = 10⁻¹. Additionally, when compared with the subpar design data, the largest gain in NNM was 26.7 times, while the biggest decreases in surface temperature and entropy were 59% and 97%, respectively. As a result, the combination of the numerical simulation and RSM study produces a novel strategy and insightful suggestions for the ideal cooling L-shaped cabinet design.     

Numerical investigation of an enhanced PTC absorber tube using cylindrical inserts

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 × 10⁴ to 7.09 × 10⁴. In the second part, the eccentricity of the cylindrical inserts is investigated under the same operating conditions. The Therminol®VP1 is the HTF that is used in this investigation's intermediate fluid. The numerical simulation indicates that the perturbators enhance the thermal behavior of the receiver and reduces the absorber tube's temperature difference.