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Abstract: In this paper, we solve the Falkner–Skan equation with heat transfer through an expansion in Fourier series, results are improved by incorporating an asymptotic analysis for the Fourier series coefficients. The results show that the classical expansion in Fourier series together with the incorporation of an asymptotic analysis for coefficients of the series delivers a solution with very good accuracy and rapid convergence when it is compared with other methods of solution found in the literature as finite difference and shooting method. [ABSTRACT FROM AUTHOR]

Abstract: The unsteady non-Newtonian blood flow in symmetric stenotic arteries is numerically simulated considering fluid–structure interaction (FSI) using the code ADINA. A two layer hyperelastic anisotropic structural model is used for the compliant arterial wall. The pressure used as outlet boundary condition was obtained running a CFD simulation for each stenosis with a physiologically-realistic time variation of pressure at inlet for different velocities. The obtained pressure drop increases in potential form with the inlet velocity for a fixed stenosis severity. The FSI results show that the maxima velocity and WSS at throat increase in exponential form with stenosis severity. The minimum and maximum effective stress at throat for stenosis severity of S =70% ranged between 47 kPa and 96 kPa at diastole and systole, respectively. [Copyright &y& Elsevier]

Abstract: In this work the unsteady non-Newtonian blood flow and mass transfer in symmetric and non-symmetric stenotic arteries are numerically simulated considering the fluid-structure interaction (FSI) using the code ADINA. Blood with hyperviscosity syndrome is considered and hyperelastic Mooney–Rivlin model is used for the compliant arterial wall. The inlet boundary condition of imposed velocity or pressure is critical to obtain realistic hemodynamic results in stenotic arteries. The FSI affects significantly the hemodynamics on the stenotic arteries models, the arteries are considerably dilated and compressed due the stenosis. The stenosis severity and geometry have important influence on recirculation length, and distribution of concentration of macromolecules, such as low density lipoproteins (LDL). [Copyright &y& Elsevier]

The unsteady laminar flow and heat transfer characteristics in a plane channel with two square bars mounted staggered to the approaching flow are numerically analyzed. A finite volume method is applied with a fine grid and time resolution. The longitudinal and transverse separation distances between the bars are varied, whereas the bar height to channel height d/H, and the Reynolds number based on channel height Re, are d/H=SHAPE="SOL" ALIGN="C" STYLE="S">18 and 800 respectively. Complex flow patterns develop in the channel due the interaction between the two staggered square bars. For the cases with L/d≥2 shedding of vortices with only one frequency are present in the flow, and biased flow with frequency modulation of the vortices shedding for the cases with L/d<2 are found. [Copyright &y& Elsevier]

The thermal performance of a compact heat exchanger with flat tubes was numerically investigated in a laminar regime by introducing longitudinal vortex generators (LVG) in arrays comprising: 9 alternating, 18 alternating, 18 aligned, 27 alternating and 39 alternating LVG. Vortex generators, in the form of delta winglets with an angle of attack of 35o, were used. For each geometry, the local heat flux, local and global Nusselt number and the friction factor were analysed. The Reynolds number varied between 400 and 2000. [ABSTRACT FROM AUTHOR]

Accurate characterization of two phase bubbly flows is crucial in many industrial processes such as fluidized reactors, ore froth flotation, etc. The bubble size determines the rate at which components present in the gas phase are transferred to the surroundings and vice versa while bubble rate defines the appropriate bubbly flow regime occurring in the heterogeneous system. This research work employs deep neural networks (DNNs) to predict bubble size and bubble rate using data obtained from validated computational fluid dynamics (CFD) computations. Pure water and slurry (in conditions similar to those employed in mineral froth flotation) case studies are evaluated. It is found that the DNN can predict the CFD results accurately when using four hidden layers, describing discontinuities in the bubbly flow regime. The relative errors computed between the CFD data and the prediction obtained by the DNN is as low as 8.8% and 1.8% for bubble size and bubble rate, respectively. These results confirm that the DNN can be applied to sophisticated fluid dynamics systems and allow developing better control process strategies since once the DNN is trained critical variables can be computed very efficiently. The slurry case study, although restricted to the application of mineral froth flotation, can also be generalized to other industrial operations keeping the exact same procedure. [ABSTRACT FROM AUTHOR]