Nelder-Mead algorithm optimization and Galerkin’s method thermal performance analysis of circular porous fins with various profiles in fully wet conditions
Volume 16, Issue 3, Summer 2019, Pages 37-57
M. r. Talaghat, F. Shafiei
Abstract The main objective of this research is to analyze optimization and the thermal performance of circular porous fins with four different profiles, rectangular, convex, triangular and concave under fully wet conditions. In this research, a linear model was used for the relationship between humidity and temperature. Also, modeling is assumed one-dimensional and the temperature changes only in the direction of the radius of the fin. Moreover, the thermal conductivity and heat transfer coefficient are a function of porosity and temperature, respectively. The governing equations are solved using the Galerkin method and the finite difference method and the use of the Gauss-Seidel algorithm. In this study, the effect of different parameters including relative humidity, Darcy number and Rayleigh number and porosity on temperature distribution, fin efficiency, and fin effectiveness was investigated. The results showed that the efficiency, effectiveness, and heat transfer rate to the base for the rectangular profile is higher than other profiles.
In this research, the Nelder-Mead algorithm is used for optimization. The results showed that to maintain optimal conditions, the ratio of thickness to fin length should be increased by increasing relative humidity or decreasing the Darcy number, Rayleigh number and porosity.
The Effects of Operational Parameters on the Efficiency of a Mixer-Settler Extractor
Volume 2, Issue 1, Winter 2005, Pages 10-23
H. Abolghasemi, H. Bahmanyar, M. Ghanadi Maragheh
Abstract The effects and influences of various operational parameters on the efficiency of mixer-settlers are thoroughly studied in this paper. One of the most important factors in designing a mixer-settler is to obtain an optimum operational extraction and overall efficiency. These two factors are dependent on various parameters such as impeller shape, size and speed of impeller, baffle size, residence time, volumetric flow rates and the ratio of heavy to light phases. In this paper, the effect of impeller speed and volumetric flowrates of two phases on efficiency are studied. Also, the effect of hold-up of each stage upon stage efficiency is studied. According to the above experiments and achieved results, it can be concluded that in general, an increase in impeller speed and solvent amount results in an increase in extraction efficiency. Also, when hold-up of the dispersed phase decreases, the stage efficiency usually increases up to a certain point.