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• The effect of an external magnetic field on hemodynamics of blood flow in a bend vessel was studied. • Blood was studied as a biomagnetic fluid through the ferrohydrodynamic approach. • Effect of curvature coefficient and the susceptibility of blood were investigated. • The maximum magnetic field strength with no effect on hemodynamics was presented. Targeted delivery of therapeutic agents such as stem cells and drugs using magnetic nanoparticles with the aid of an external magnetic field is an emerging treatment modality for many diseases. To this end, understanding the effect of magnetic field on hemodynamics in human body is of great importance. In this article, the effect of external magnetic field, induced by a straight current wire, on hemodynamics of blood flow in a 90° horizontal bend vessel with circular cross section was investigated numerically using ANSYS Fluent®. The blood was considered as laminar, Newtonian, steady and incompressible. To investigate the effect of non-uniform magnetic field effects on the blood flow, the ferrohydrodynamics principles (FHD) were employed. A user-defined function (UDF) was developed to apply the magnetic field effects as source terms. The magnetic susceptibility of blood in oxygenated (in arteries) and deoxygenated (in veins) blood vessels were considered negative and positive values, respectively. The effect of magnetic number, Reynolds number, curvature coefficient and the position of the current wire on flow velocity, static pressure, and shear stress were investigated. The results showed that the Wall Shear Stress (WSS) and static pressure were enhanced with the increase of magnitude of magnetic number. In addition, it was observed that magnetic field has superior impact on the hemodynamic of venous vessel (deoxygenated blood) in comparison with the hemodynamic of artery vessel (oxygenated blood). By studying the effect of curvature coefficient and Reynolds number on WSS, it is concluded that in high curvature coefficient and low Reynolds number, the effect of magnetic field is greater than low curvature coefficient and high Reynolds number, respectively. [ABSTRACT FROM AUTHOR]

Convective heat transfer of Al 2 O 3 –water nanofluid over an equilateral triangular obstacle with an optimization analysis is carried out to determine the optimum conditions for the maximum heat transfer rate and the minimum drag coefficient. Orientations of the obstacle, values of the solid volume fraction, and Reynolds number are selected as the input parameters. The analysis is performed according to the Response Surface Methodology. The response surface equation is obtained using the design of the experiments features. Two-dimensional unsteady equations with the relevant boundary conditions have been solved using finite volume method. Three different orientations of the triangular obstacle are defined for the optimization procedure. The computational simulations are done for different Reynolds numbers ( 1 ≤ Re ≤ 180 ), solid volume fractions ( 0 ≤ φ ≤ 0.05 ) and orientations of the triangular obstacle ( 0 ° ≤ θ ≤ 60 ° ). Also, a comparison is performed between the results of CFD analysis and Response Surface Methodology. It is found that the minimum drag coefficient is occurred at θ = 35.13°, Re = 97.6 and φ = 0.01 and the maximum Nusselt number is found at θ = 8.49°, Re = 180 and φ = 0.05. [ABSTRACT FROM AUTHOR]