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A time-varying flow through a porous medium of a dusty viscous incompressible Bingham fluid in a circular pipe is studied. A constant pressure gradient is applied in the axial direction, whereas the particle phase is assumed to behave as a viscous fluid. The effect of the medium porosity, the non-Newtonian fluid characteristics, and the particle phase viscosity on the transient behavior of the velocity, volumetric flow rates, and skin friction coefficients of both the fluid and particle phases is investigated. A numerical solution is obtained for the governing nonlinear momentum equations by using the method of finite differences.

A steady-state mixed convection boundary layer flow of an electrically conducting nanofluid (Cu-H₂O) obeying a power-law model in the presence of an alternating magnetic field due to a stretching vertical heated sheet is investigated numerically through the use of Wolfram Mathematica. The surface stretching velocity and the surface temperature are assumed to vary as linear functions of the distance from the origin. A similarity solution is presented, which depends on the nanoparticle volume fraction, power-law parameter, magnetic field parameter, buoyancy convection parameter, and modified Prandtl number.

A mathematical model of the influence of a medium on a solid body with some part of its external surface being flat is considered with due allowance for an additional dependence of the moment of the medium action force on the angular velocity of the body. A full system of equations of motion is given under quasi-steady conditions; the dynamic part of this system forms an independent third-order system, and an independent second-order subsystem is identified. A new family of phase portraits on a phase cylinder of quasi-velocities is obtained. It is demonstrated that the results obtained allow one to design hollow circular cylinders (“shell cases”), which can ensure necessary stability in conducting additional full-scale experiments.

It is proved analytically that the complex growth rate of an arbitrary oscillatory motion of growing amplitude in ferromagnetic convection with magnetic-field-dependent viscosity in a rotating sparsely distributed porous medium for the case of free boundaries is located inside a semicircle in the right half of the plane whose centre is at the origin of the coordinate system and whose radius depends on the Rayleigh number, Prandtl number, Taylor number, and magnetic number. Bounds for the case of rigid boundaries are also derived.

This paper presents a new method of analytical calculation of the flow rate of the gas mixture and the concentration of the growth component during gas-phase epitaxy in a reaction chamber with a rotating substrate holder disk. The concentration of the growth component is analyzed in relation to a number of epitaxy process parameters.

This paper describes the experimental study of the conditions of heat and mass transfer in horizontal directional solidification of refractory oxide compounds in the case of heating the rear part of the container from below. It is established that such heating causes significant changes in the nature of the mass transfer in the central area of the liquid layer. As a result, a stable structure is formed, providing the liquid flow from the rear of the container to the crystallization front, mass transfer in the near-surface and near-bottom vortices, and a more efficient mixing of the melt.

The aim of the present contribution is the determination of the thermoelastic temperatures, stress, displacement, and strain in an infinite isotropic elastic body with a spherical cavity in the context of the mechanism of the two-temperature generalized thermoelasticity theory (2TT). The two-temperature Lord-Shulman (2TLS) model and two-temperature dual-phase-lag (2TDP) model of thermoelasticity are combined into a unified formulation with unified parameters. The medium is assumed to be initially quiescent. The basic equations are written in the form of a vector matrix differential equation in the Laplace transform domain, which is then solved by the state-space approach. The expressions for the conductive temperature and elongation are obtained for at small times. The numerical inversion of the transformed solutions is carried out by using the Fourier-series expansion technique. A comparative study is performed for the thermoelastic stresses, conductive temperature, thermodynamic temperature, displacement, and elongation computed by using the Lord-Shulman and dual-phase-lag models.

The aim of this study is to predict the improvement in the film cooling performance over a flat plate through a single row of cylindrical holes with different streamwise angles by using the Ansys CFX software package. In order to improve the film cooling effectiveness, a short crescent-shaped block is placed downstream of a cylindrical cooling hole. The numerical results of the cylindrical hole without the downstream short crescent-shaped block are compared with experimental data.

This article addresses the boundary layer flow of a thixotropic fluid past an exponentially stretching sheet with heat transfer. The governing partial differential equations are reduced to an ordinary differential equation whose solution is found by the homotopy analysis method. The numerical values of the skin friction coefficient and Nusselt number are compared with available data.

The effect of melting on a steady boundary layer stagnation-point flow and heat transfer of an electrically conducting micropolar fluid toward a horizontal shrinking sheet in the presence of a uniform transverse magnetic field and thermal radiation is studied. A similarity transformation technique is adopted to obtain self-similar ordinary differential equations, which are solved numerically. The present results are found to be in good agreement with previously published data. Numerical results for the dimensionless velocity and temperature profiles, as well as for the skin friction and the rate of heat transfer are obtained.