Radiative MHD flow of Casson hybrid nanofluid over an infinite exponentially accelerated vertical porous surface

Fractional neutron point kinetics equations for nuclear reactor dynamics

Investigation of natural convection of magnetic nanofluid in an enclosure with a porous medium considering Brownian motion

The aim of the current study is natural convection analysis conjugated with entropy generation analysis in an incinerator shaped permeable enclosure loaded with Al2O3–H2O nanofluid subjected to the magnetic field with a rectangular wavy heater block positioned on the bottom of the cavity wall. The bottom and top horizontal walls are adiabatic; the inclined and vertical walls are thought to be cooled. Firstly, the governing expressions and standard k–e turbulence model are rewritten from dimensional form to non-dimensional form using dimensionless parameters such as vorticity and stream function. In the next step, the equation of entropy generation is written in dimensionless form. Then, the system of non-dimensional governing equations is solved by the finite volume method (FVM) conjugated with a non-dimensionalization scheme using ANSYS Fluent. Fine grids (wall y+ < 2) with inflated layers have been used for the higher Rayleigh number. The effects of the Rayleigh number in the laminar region (Ra = 103, 104, and 105) and turbulent region (Ra = 108, 0.5 × 109, and 109), Darcy number (Da = 0.01 and 100), Hartmann number (Ha = 0 and 40), and the nanoparticles (
$$ \phi = 2{{\% }} $$

) on the entropy generation number and natural convection are investigated. The validation results were in good agreement with those of the literature. The results demonstrate that for the laminar region, the Nusselt number and entropy generation number increase as the Rayleigh number and the Darcy number grow, whereas both of them abate as Hartmann number increases. In the turbulent region, the average Nusselt number decreases by ascending the Darcy number. Also, for turbulent region (Ra = 109), convection flow strength decreases 6.28% when Hartmann number increases from 0 to 40, whereas the entropy generation number increases 31.5% at Da = 0.01.

Magnetohydrodynamic natural convection and entropy generation analyses inside a nanofluid-filled incinerator-shaped porous cavity with wavy heater block

Review on treatment technology of salt wastewater in coal chemical industry of China

In this research, a micro pin fin heat sink with a baffle where pure water flows through was simulated and analyzed in 3D by ANSYS Fluent in the laminar range of 50 ≤ Re ≤ 250. Here we tried to change the baffle’s type and dimensions for examining the effect of the baffle on the heat transfer. Baffles that used were single segmental baffle, double segmental baffle, and triple segmental baffle with four different overlaps namely 60%, 40%, 20%, and 0%. The results were compared with micro pin fin heat sink without baffle. The results show that using baffle in pin fins in all Reynolds number increases the heat transfer rate. However, by increasing the Reynolds number the pressure drop increases. The heat sink with 20% overlaps double segmental baffle has the highest heat transfer rate. The heat transfer rate in a 20% overlap and Reynolds number 250 is 47.37% higher than the heat sink without baffle. The increase in the mass flow rate has a great effect on the heat transfer rate.

Effect of the baffle on the performance of a micro pin fin heat sink

Simulation of the dynamic behavior of a rectangular single-phase natural circulation vertical loop with asymmetric heater

HAZOP-study on heavy water research reactor primary cooling system

Forced reflood modeling in a 2 × 2 rod bundle with a 90% partially blocked region

The object of this study is entropy generation analysis in the concentric annuli of a gas insulation transmission line enclosure (GIL) loaded with air and SF6-N2 mixture gas The inner and outer cylinders of the cavity are hot and cold, respectively Because of symmetric conditions the ½ cylinder is considered for modeling The standard k–ɛ turbulence model, the equation of entropy generation, and the conservation equations are transformed from dimensional form to non-dimensional form utilizing the definition of dimensionless parameters, stream function, and vorticity Then dimensionless governing equations are solved by a finite volume method (FVM) using an innovative ANSYS Fluent non-dimensionalization scheme Inflated layers applied to the fine grids to improve the simulation capability for turbulent modeling The effects of the Rayleigh number at Ra = 25 × 106, 17 × 109, 21 × 109, 42 × 109 and 57 × 109 are investigated The results demonstrate that the Nusselt number grows as the Rayleigh number grows and entropy generation number and the Bejan number decreases as the Rayleigh number increases The GILs have a proper morphology in geometry that reducing the high irreversibility in higher Rayleigh numbers conditions

S. Tashakor

Papers

Effect of the baffle on the performance of a micro pin fin heat sink

Simulation of the dynamic behavior of a rectangular single-phase natural circulation vertical loop with asymmetric heater

HAZOP-study on heavy water research reactor primary cooling system

Forced reflood modeling in a 2 × 2 rod bundle with a 90% partially blocked region

Entropy generation in concentric annuli of 400 kV gas-insulated transmission line