In this paper, the process of natural convection heat transfer (NCHT) and production of entropy (POF) in a portion of a tube has been modeled two-dimensionally. The examined problem is a quarter-tubular enclosure (quarter of a tube) which is filled with water-alumina nanofluid and subjected to a magnetic field (MF) of strength B0 at angle relative to horizon. Lattice Boltzmann Method (LBM) is used to simulate this problem. The ranges of parameters used in this investigation are: 0 < ω < 90, 0 < Ha < 60, and 0.1 < L, H < 0.5, and the obtained results include the Nusselt number (Nu), generated entropy, and Bejan number (Be). The results of thermal and dynamic analyses indicate that by growing the Hartmann number (Ha), the NCHT and POF values go up and the Bediminishes. Heat transfer is also improved by increasing the length of the enclosure’s hot walls. The highest amount of heat transfer occurs at the MF angle of 60º, and it is 10.3% greater than the amount of heat transfer occurring at horizontal MF. Finally, an artificial neural network (ANN) was used to simulate the cavity performance based on these parameters. An optimization is performed on the parameters of heat source length and Ha. The optimization is aimed at finding suitable parameter values that lead to the highest heat transfer rate and lowest POF. A table listing a number of optimal points has been presented at the end of the paper.

This article investigates unsteady flow of viscous fluid flow by a rotating stretchable disk. Porous medium is considered and describe by Darcy’s law. Using the flow assumption, the flow model governs by system of partial differential equation (PDE). New dimensional less variables are introduce to covet the system to dimensionless from. Finite difference method is utilized to solve dimensionless PDE’s system. Effects of important flow parameters on velocity, temperature, Nusselt number and skin fraction are examined graphically. Results outcomes show that velocity decay though porosity parameter while temperature show is increasing function of Prandl and Eckert number. Skin fraction and Nusselt number increase for higher porosity parameter and Eckert number respectively.