Flow Of Viscous Fluid Research Articles

Impact of Dual Phase Lag on Natural Convection Flow in a Porous Vertical Channel in the Presence of Periodic Boundary

ABSTRACTThe dual‐phase‐lag (DPL) heat conduction model is utilized in this research to analyze the fluid flow of viscous fluid passing through a porous vertical channel with periodic boundary conditions. Periodic heating is subjected to the channel boundary. Equations regarding the model, including the momentum and energy equations, in which the DPL term is incorporated, all in dimensional form, are stated and are being transformed to their dimensionless form, then solved analytically by undetermined coefficients and variation of parameters. The actual expressions of temperature and velocity, as well as the heat transfer rate and skin friction, are determined. The effects of the DPL parameters, suction/injection, Prandtl number, heat source/sink, and Strouhal number on the dimensionless temperature and velocity profiles are demonstrated using graphs that are constructed with the aid of MATLAB. It was found during the investigation that the introduction of the DPL model, together with suction/injection in the channel, enhances the velocity and fluid temperature within the channel. Also, the decreasing effect of temperature gradient phase lag on fluid temperature and velocity conversed with that of heat flux phase lag. As an important contribution, the discovery of the effects of the phase‐lag parameters of the DPL model and suction/injection on fluid temperature and velocity would significantly help researchers advance the design of electrical and electronic systems.

Effect of shear-thinning rheology on the dynamics and pressure distribution of a single rigid ellipsoidal particle in viscous fluid flow

This paper evaluates the behavior of a single rigid ellipsoidal particle suspended in homogeneous viscous flow with a power-law generalized Newtonian fluid rheology using a custom-built finite element analysis (FEA) simulation. The combined effects of the shear-thinning fluid rheology, the particle aspect ratio, the initial particle orientation, and the shear-extensional rate factor in various homogeneous flow regimes on the particles dynamics and surface pressure evolution are investigated. The shear-thinning fluid behavior was found to modify the particle's trajectory and alter the particle's kinematic response. Moreover, the pressure distribution over the particle's surface is significantly reduced by the shear-thinning fluid rheology. The FEA model is validated by comparing results of the Newtonian case with results obtained from the well-known Jeffery's analytical model. Furthermore, Jeffery's model is extended to define the particle's trajectory in a special class of homogeneous Newtonian flows with combined extension and shear rate components typically found in axisymmetric nozzle flow contractions. The findings provide an improved understanding of key transport phenomenon related to physical processes involving fluid–structure interaction such as that which occurs within the flow field developed during material extrusion–deposition additive manufacturing of fiber-reinforced polymeric composites. These results provide insight into important microstructural formations within the print beads.

Flow of viscous electron fluids over sphere

The transport of strongly interacting electrons in ultrapure crystals is usually considered as the movement of an electron fluid. The study of various physical phenomena associated with the flow of electrons in superconducting materials in many problems can be realized from the point of view of the movement of viscous fluids. The article presents an analytical solution to the problem of electron fluid flowing around a spherical obstacle in the case when electrons strongly interact with each other. Expressions for the profiles of the longitudinal and transverse velocity components were obtained for the first time. The influence of electron collision effects and slip effects on the vibrational characteristics of velocity profiles is analyzed. The impossibility of flow separation and the formation of a Karman vortex street in an e-fluid are shown.

Quantum spin representation for the Navier-Stokes equation

We develop a quantum representation for Newtonian viscous fluid flows by establishing a mapping between the Navier-Stokes equation (NSE) and the Schrödinger-Pauli equation (SPE). The proposed nonlinear SPE incorporates the two-component wave function and the imaginary diffusion. Consequently, classical fluid flow can be interpreted as a non-Hermitian quantum spin system. Using the SPE-based numerical simulation of viscous flows, we demonstrate the quantum/wavelike behavior in flow dynamics. Furthermore, the SPE equivalent to the NSE can facilitate the quantum simulation of fluid dynamics. Published by the American Physical Society 2024

Investigating the Morphology of a Free-Falling Jet with an Accurate Finite Element and Level Set Modeling

This study investigates the morphology of a free-falling liquid jet by using a computational approach with an experimental validation. Numerical simulations are developed by means of the Finite Element Method (FEM) for solving the viscous fluid flow and the level set method in order to track the interface between the fluid and air. Experiments are conducted in order to capture the shape of a free-falling jet of viscous fluid via circular orifice, where the shape is measured optically. The numerical results are found to be in agreement with the experimental data, demonstrating the validity of the proposed approach. Furthermore, we analyze the role of the surface tension by implementing linear as well as nonlinear surface energy models. All computational codes are developed with the aid of open-source packages from FEniCS and made publicly available. The combination of experimental and numerical techniques provides a comprehensive understanding of the morphology of free-falling jets and may be extended to multiphysics problems rather in a straightforward manner.

Impact of peristaltic inclined Tube of the Newtonian viscous fluid flow with different wavelengths described by linear Navier-Stokes equations

Impact of peristaltic inclined Tube of the Newtonian viscous fluid flow with different wavelengths described by linear Navier-Stokes equations

Some Exacts Solutions of Two Dimensional Unsteady Incompressible Magnetohydrodynamic Flow of Viscous Fluid by Ansatz Method

Some Exacts Solutions of Two Dimensional Unsteady Incompressible Magnetohydrodynamic Flow of Viscous Fluid by Ansatz Method

The Impact of a Non-Uniform and Transient Magnetic Field on Natural Convective Jeffrey Fluid Flowing over a Heated Porous Plate: A Comparitive Study

Examining the effects of varying transient magnetic fields and their orientations on boundary layers aids in understanding the flow in complex surface geometries, turbulence control, drag reduction, aircraft and ship design, groundwater management, and the study of construction and coastal engineering. The study introduces a novel dynamics of the boundary layer of a natural convective Jeffrey fluid flowing over an erect porous moving plate under the influence a non-uniform and transient magnetic field M ˜ that grows exponentially over time with α as an accelerating parameter. The governing partial differential equations (PDEs) were non-dimensionalized using similarity variables and then solved analytically using the perturbation technique. The impact of various thermosphysical properties including chemical reactions, thermal source, Jeffrey fluid parameter and plate permeability on the fluid flow were presented graphically utilizing finite difference approximation(FDA) technique in MATLAB ODE15s solver. The study highlighted a notable decrease in shear stress (skin friction) by introducing M ˜ to the vertical plate results in the reduction of momentum boundary layer, accompanied by an increment in thermal boundary layer. Also, the results shows that increasing the magnitude of α leads to decrease the velocity and increase the temperature distribution curve. Additionally, the concentration profile was also found to decrease with stronger chemical reactions. Furthermore, key parameters like heat and mass flux were estimated and discussed through comparison tables. Understanding the effects of unsteady and externally applied increasing magnetic field M ˜ on viscous fluid flow have potential applications in biomedical engineering, such as the design of magnetic drug delivery systems and the analysis of blood flow in human body.

Curved-pipe flow with boundary conditions involving Bernoulli pressure

In this article, we study the steady-state flow of the incompressible viscous fluid through a thin distorted pipe with an arbitrary central curve. We prescribe the inflow and outflow boundary conditions involving the Bernoulli pressure with a given pressure drop. Using the multiscale expansion technique with respect to the pipe's thickness, we construct the higher-order asymptotic approximation of the flow given by the explicit formulae for the velocity and pressure. We also perform a detailed error analysis justifying the usage of the proposed solution and indicating its order of accuracy. For more information see https://ejde.math.txstate.edu/Volumes/2024/63/abstr.html

Cilia-assisted flow of electrically conducting micropolar fluid in a heated curved channel under Soret and Dufour effects

Cilia flow plays a crucial role in biological systems such as the movement of mucus in the respiratory tract, circulation of cerebrospinal fluid in the brain, and propulsion of sperm cells. Understanding the cilia flow of viscous fluids is essential for elucidating the biomechanics of these processes and their implications for health and disease. Motivated by such numerous biomedical applications, this article aims to exhibit the influence of heat and mass transfer on the ciliary flow of an electrical conducting micropolar fluid in a curved channel. The energy and concentration equations are modulated with viscous dissipation, Soret, and Dufour effects. The constitutive equations are simplified by the lubrication approximation and then solved numerically using the implicit finite difference method (FDM). Results for velocity, pumping phenomenon, concentration, thermal field, rate of heat transfer, streamlines, skin friction coefficient, Nusselt number, and Sherwood number are analyzed subject to pertinent parameters. The study reveals that velocity is enhanced via both the micropolar parameter and curvature parameter. Temperature enhances for larger values of Dufour and Brickman numbers. Furthermore, the radial magnetic field plays a resistive role in the trapped bolus. The findings presented in this study should prove beneficial for researchers in the domains of medicine, engineering, science, and fluid mechanics. Further, it is found that the micropolar fluid model is more suitable for biofluids like blood.

Numerical simulation of the movement of the water surface with macroscopic particles during a partial dam break for various complex reliefs

In this paper, it was considered a numerical simulation of the water surface movement during the partial collapse of the destruction of a dam with complex terrain. The numerical simulations took into account debris after a partial collapse of the dam, which imitates debris and moves downstream with the water flow. Carrying out these calculations brings the results closer to the real scenario. The mathematical model was based on the Navier–Stokes equations and uses the turbulent large eddy method (LES) model describing the flow of an incompressible viscous fluid. To describe the movement of a two-phase fluid, the volume of fluid (VOF) methods for the phase were used, and the Discrete Phase Model (DPM) and Macroscopic Particle Model (MPM) were used to describe the movement of particles. For the numerical solution of this system of equations, the Pressure Implicit Split Operator (PISO) numerical algorithm was chosen. The results show that the model is accurate and capable of handling very complex interactions such as particle transport or hydrodynamic actions on structures if the appropriate scales are reproduced. Also in this work, a three-dimensional (3D) model of the flow of a dam break on uneven terrain was considered and combined problems were performed that are closer to real conditions. For combined problems, flood zones and flood times were determined, knowledge of which will help evacuate people from dangerous areas. The accuracy of the 3D model and the selected numerical algorithm were verified using two natural measurements.

Numerical analysis of MHD Casson fluid streaming above a stretching surface with energy transfer

In this study, we have numerically inspected the nature of viscous fluid flow in the Casson fluid with heat and mass transmissions over an elongating sheet. A magnetic field is implemented along the normal direction of the flow. The leading partial differential equations are transmuted into solvable ordinary differential equations using some suitable similarity conversions. Graphical and tabular presentations of the skin friction, the local Sherwood number, the Nusselt number are provided.

Метод R-функцій для розв’язання задачі масообміну циліндричного тіла з твірною у вигляді кривої Ламе з в’язкою нестисливою рідиною

The problem of stationary mass exchange of a cylindrical body with viscous incompressible fluid flow is reduced to solving the equation for concentration with the corresponding boundary conditions on the surface of the body and at infinity. Applying the constructive apparatus of the R-functions theory allows us to accurately take into account the geometry of the domain, as well as the boundary conditions together with the condition at infinity. The R-function method was proposed by V. L. Rvachev, Ukraine National Academy of Sciences academician. For boundary value problems of mathematical physics, this method allows constructing the so-called structure of the solution of the boundary value problem, i.e. a bundle of functions that accurately takes into account all boundary conditions of the problem and depends on some uncertain components. The choice of these uncertain components is performed in such a way as to satisfy (in a certain sense) the equation of the problem. For this, one can use standard numerical methods of mathematical physics (the Ritz method, the Galerkin method, the least squares method, collocations method, etc.). It should be noted that the geometry of the region is taken into account exactly, i.e. in particular, there is no replacement of curvilinear sections of the boundary with polygonal lines inscribed in them, as it is done, for example, in the finite element method. The purpose of this article is to apply the R-functions method to the problem of mass exchange of a cylindrical body formed by the Lame curve, with a viscous incompressible fluid flowing around it. To achieve this goal, a complete structure of the solution of a linear boundary value problem for concentration is constructed by the R-functions theory methods, and a numerical algorithm based on the Galerkin method for approximating indefinite components in the problem structure is used. The degree of rigor and the conditions for using the considered equations of fluid motion are not considered in the work; these equations are considered as mathematical models subject to numerical algorithmization

Hydrothermal analysis of time‐fractional magneto hydrodynamic viscous fluid flow on a plate

Hydrothermal analysis of time‐fractional magneto hydrodynamic viscous fluid flow on a plate

Convective diffusive thermal flow over an inclined surface with viscous dissipation and aligned magnetic field applications

This investigation incorporating the fluctuation in heat and mass transfer associated to the mixed convection magnetized flow of viscous fluid due to inclined surface with porous media. The contribution of Soret effects and viscous dissipation appliances is addressed. Furthermore, the heat transfer improvement is also assessed by thermal radiation, heat source and joule heating effects. The chemical reaction enrollment is also studied for concentration phenomenon. The convection of problem into non-dimensional framework is based on implication of new variables. The perturbation technique is followed to tracking the analytical outcomes. Physical visualization and interpretation of results under the influence of perturbed parameters have been studied. It is observed that heat and mass transfer enhances due to Soret number. Presence of chemical reaction leads to decrement of concentration profile. Claimed results presents applications in heat and mass transfer processes, chemical reaction, manufacturing systems, chemical engineering, extrusion processes etc.

Numerical Investigation of Oblique Currents’ Effects on the Hydrodynamic Characteristics of Ships in Restricted Waters

The influence of oblique currents in narrow and shallow channels causes the fluid flow around ships to become complex. To analyze the hydrodynamic characteristics of a ship in such channels, it is essential to examine the influence of oblique currents on the ship’s hydrodynamic characteristics. In this study, current direction, ship speed, current speed, and water depth were identified as determinants affecting the hydrodynamic characteristics of a ship. Numerical simulations were conducted on a large oil tanker to investigate the effects of these factors on the ship’s hydrodynamic characteristics. The viscous fluid flow was modeled using the unsteady Reynolds-averaged Navier–Stokes (URANS) equations in conjunction with the k-ε turbulence model. The URANS equations were discretized using the finite volume method. The numerical results indicate substantial differences in the hydrodynamic characteristics of ships under oblique current conditions compared to still-water conditions. At a current direction of β = −45°, the direction of the sway force is consistent with that of still water’s sway force, which is an attractive force. The yaw moment at β = −45° changes from a bow-out moment under still-water conditions to a bow-in moment. Conversely, at a current direction of β = 45°, the sway force shifts from an attractive force under still-water conditions to a repulsive force. The yaw moment acts as a bow-out moment, which is consistent with that observed in still-water conditions. Furthermore, the influence of hydrodynamic characteristics on a ship varies significantly with changes in ship speed, current speed, and water depth. To ensure the safe navigation of ships, it is essential to develop and apply comprehensive strategies and countermeasures that account for practical conditions.

Approximation of Classical Two-Phase Flows of Viscous Incompressible Fluids by a Navier–Stokes/Allen–Cahn System

We show convergence of the Navier–Stokes/Allen–Cahn system to a classical sharp interface model for the two-phase flow of two viscous incompressible fluids with same viscosities in a smooth bounded domain in two and three space dimensions as long as a smooth solution of the limit system exists. Moreover, we obtain error estimates with the aid of a relative entropy method. Our results hold provided that the mobility mε>0\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$m_\\varepsilon >0$$\\end{document} in the Allen–Cahn equation tends to zero in a subcritical way, i.e., mε=m0εβ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$m_\\varepsilon = m_0 \\varepsilon ^\\beta $$\\end{document} for some β∈(0,2)\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\beta \\in (0,2)$$\\end{document} and m0>0\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$m_0>0$$\\end{document}. The proof proceeds by showing via a relative entropy argument that the solution to the Navier–Stokes/Allen–Cahn system remains close to the solution of a perturbed version of the two-phase flow problem, augmented by an extra mean curvature flow term mεHΓt\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$m_\\varepsilon H_{\\Gamma _t}$$\\end{document} in the interface motion. In a second step, it is easy to see that the solution to the perturbed problem is close to the original two-phase flow.

On particle-modified velocity fields of particulate Taylor–Couette flow

Particulate Taylor–Couette flow of a particle-laden viscous fluid between two coaxial rotating cylinders is studied using a novel hydrodynamic model. With the volume fraction of particles as the dimensionless small parameter, explicit leading-order solutions are derived for the general case of dispersed particles heavier or lighter than the carrier fluid. It is shown that, unlike the classical azimuthal velocity field of a clear fluid without particles, dispersed particles generally have a radial velocity toward the outer or inner cylinder depending on the angular velocities and radii of the two cylinders and whether the particles are heavier or lighter than the carrier fluid, in qualitative agreement with some known results reported in literature on heavier or lighter particles, respectively. In some cases, such as the flow driven by rotating inner cylinder with a wider gap between the two cylinders and a moderate value of Stokes number of particles, our results predict the existence of a circular ring between two cylinders, which attracts or repels heavier or lighter particles that could have relevant physical implications. Beyond existing literature on the Taylor–Couette flow with neutrally buoyant particles, these results could offer new insight and useful explicit solutions to the Taylor–Couette flow with particles heavier or lighter than the carrier fluid.

Annular generalized Couette flow of immiscible viscous fluids in an anisotropic porous medium

Annular generalized Couette flow of immiscible viscous fluids in an anisotropic porous medium

Modeling and predicting heat transfer performance in bioconvection flow around a circular cylinder using an artificial neural network approach

The current research aims to study the heat transfer rate in mixed convection flow of viscous fluid along a vertical cylinder containing swimming microorganisms and velocity slip effects. The thermal and solutal processes are examined using gyrotactic microorganisms, chemical reaction and slip conditions. The non-linear (PDEs) of the governing flow are transformed into set of highly nonlinear (ODEs) by employing appropriate similarity transformations, which are then resolved computationally by Runge-Kutta-Fehlberg 4th order toward with shooting approach. The predicted solution is derived using the Levenberg-Marquardt scheme combined with a backpropagation neural network (LMS-BPNN). The labelled data sheet is divided into three parts: 80% data is used for training, 10% for validation and 10% for testing. The performance of the proposed AI-based LMS-BPNN is examined in term of MSE for considered scenarios. An optimal solution is achieved at 675, 397, 727, 647, and 711, epochs, while performance in terms of MSE for these epochs is to be 1.06×E−9, 8.47×E−10, 9.20×10−9, 9.94×E−10,and 9.09×10−10. The assigned computational valuations and ANN valuations are in excellent alignment than those existing studies on numerous special cases. The predicted solution with AI-based technique LMS-BPNN is reliable, well-organized, and easy to handle the thermal and solutal transport analysis of flow across a stretchable cylinder. The validity of proposed LMS-BPNN algorithm is examined with absolute error analysis and error is found to be approximately 10−4.