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• Effects of magnetic field on heat transfer and entropy generation. • Inclined cavity with Straight, Inclined and Curved Blades containing nanofluid. • Solving nonlinear governing equations by finite volume method and SIMPLE algorithm. • Four different nano powders shapes, namely platelets, cylinders, Fins, and bricks. • The average Nusselt number and entropy generation are decreased by adding different nano powders. Nanopowder shapes are highly effective in nanofluids properties. This study was a numerical analysis of the effect of nanopowder morphology on the natural convection and irreversibilities of water/alumina nanofluids. To this end, a square enclosure was used with constant cold (T c) and hot (T h) temperatures at its right and left walls, respectively. The horizontal surfaces were isolated and the enclosure was exposed to a magnetic field. Two Fins were located on the left wall sharing the same temperature as the wall. The control volume method was used to derive the algebraic form of the equations, and a SIMPLE algorithm written in Fortran was used for the simulations. To investigate the effect of nanopowder shapes, four different shapes, namely platelets, cylinders, blades, and bricks, were used. For a better comparison, nanofluids with different morphologies were compared with a Brownian motion-incorporated model. The results showed that this model predicts the highest heat transfer rate and entropy generation. As its most important result, this paper concluded that free heat convection in nanofluids is not necessarily increased by addition of nanopowder, and in some cases, the Nu number and irreversibilities can be decreased because of the significant increase in nanofluid viscosity. It was also observed that the Nu rises with Ra and falls with the magnetic field intensity. Generally speaking, the greatest and lowest heat transfer coefficients were obtained using the Angled and straight Fins, respectively. [ABSTRACT FROM AUTHOR]

The combined impacts of inclined Lorentz force and thermal radiation on natural convection inside a porous chamber having micropolar nanoliquid and elliptical tilted heater are examined numerically. Micropolar fluid containing nanoparticles of copper oxide of low concentration circulates within the domain affected by the buoyancy and Lorentz forces. KKL approach is applied to define dependency of the nanofluid heat conductivity and viscosity on the nano-sized particles concentration and temperature, simultaneously. Governing equations with relevant boundary conditions written in non-dimensional stream function were solved by the Galerkin finite element method. An impact of important control parameters on micropolar nanofluid flow and heat exchange was analyzed. It was shown that change of the elliptical heater orientation reflects a significant modification of considered isolines and heat exchange rate. At the same time, average Nusselt number has maximum values for α = 0 and α = π and minimum value at α = π/2. [ABSTRACT FROM AUTHOR]

• Non-Newtonian blood flow in the cerebral blood vessels studied. • We used Magnetic Resonance Image to take Digital Imaging. • Impact of Reynolds number, power-law indexes and heat fluxes are investigated. • Pressure drop increase with increasing the Reynolds number and power-law index. • The maximum Nusselt number vessels accrued in the running position of the body. Hemodynamic blood flow analysis in the cerebrovascular is has become one of the important research topics in the bio-mechanic in recent decades. The primary duty of the cerebral blood vessel is supplying Glucose and oxygen for the brain. In this investigation, the non-Newtonian blood flow in the cerebral blood vessels studied. For modeling the geometry of this problem, we used Magnetic Resonance Image (MRI) approach to take Digital Imaging and Communications in Medicine (DICOM) images and using an open-source software package to construct the geometry, which is a complicated one. The power-law indexes, heat flux, and Reynolds number range in the investigation are 0.6 ≤ n ≤ 0.8, 5 ≤ q ≤ 15 Wm −2 and 160 ≤ Re ≤ 310. Effects of Reynolds number, power-law indexes and heat fluxes are investigated. We found that the pressure drop increase with increasing the Reynolds number and power-law index. The maximum Nusselt number in the cerebral blood vessels accrued in the running position of the body in n = 0.8. Also, the highest average wall shear stress occurs in maximum power-law indexes and Reynolds number. By increasing the power-law index and Reynolds number, the wall shear stress increases. [ABSTRACT FROM AUTHOR]