Two-dimensional Incompressible Flow Research Articles

Fractal structures in the chaotic advection of passive scalars in leaky planar hydrodynamical flows.

The advection of passive scalars in time-independent two-dimensional incompressible fluid flows is an integrable Hamiltonian system. It becomes non-integrable if the corresponding stream function depends explicitly on time, allowing the possibility of chaotic advection of particles. We consider for a specific model (double gyre flow), a given number of exits through which advected particles can leak, without disturbing the flow itself. We investigate fractal escape basins in this problem and characterize fractality by computing the uncertainty exponent and basin entropy. Furthermore, we observe the presence of basin boundaries with points exhibiting the Wada property, i.e., boundary points that separate three or more escape basins.

Parametric analysis of the flow past a square cylinder in the interface of two different-velocity streams

We address the linear stability of the two-dimensional incompressible flow past a square cylinder immersed in the wake of an upstream splitter plate, which separates two streams of different velocities, UT (top) and UB (bottom), to three-dimensional perturbations. The analysis is done in the so-called wake transition regime, across which two-dimensional vortex shedding incorporates spanwise modulation. In addition to the top and bottom stream Reynolds numbers (ReT,B=DUT,B/ν, with D the square cylinder side and ν the kinematic viscosity of the fluid), a parametric analysis is conducted to gauge the effects of splitter plate length (S) and the gap between the trailing edge of the splitter plate and the front face of the cylinder (G) on the leading three-dimensionalizing instabilities. Modes akin to the A- and B-type instabilities that characterize the wake transition regime past circular and square cylinders in homogeneous incoming flow are observed only at very small values of the top-to-bottom Reynolds number ratio R=ReT/ReB, while a third mode, mode C, is ubiquitous beyond more than very mild values of R. Increasing S at constant small G has a stabilizing effect on mode C, whose onset is pushed to higher values of R. Only for long S is mode A observed. Fixing a short S and increasing G results instead in a destabilization of mode C, and mode B is favored over mode A.

Numerical analysis of velocity slip and magnetic Soret effect on dissipative Maxwell liquid motion about a stretching wall with heat source/sink

The main aim of present numerical analysis is to explore the effects of viscous dissipation and velocity slip on the two-dimensional steady-state viscous incompressible flow of Maxwell fluid over a stretching sheet under the infleunce of magnetic field. Novel collective effects of heat source/sink and Soret impacts have been included in the governing equations to explore the salient features of heat and mass transport mechanism. Further, the velocity slip is introduced into the boundary conditions to depict the momentum transport behavior in the flow region. A typical Maxwell fluid model is deployed to separate the non-Newtonian flow behavior from that of classical Newtonian fluids. However, the visco-elastic Maxwell fluid finds its abundant applications in various fields of engineering and medicine such as plastic sheet drawing, metallurgy, polymer sheet extrusion, chemical engineering, electronic cooling, injection molding and nuclear cooling and many others. Inspired by these applications, authors have made an attempt to disclose the magneto-thermo salient features of slip flow of Maxwell fluid over stretching wall under Soret effect. The current physical situation results the highly nonlinear coupled two-dimensional steady-state partial differential equations and which are not amenable to any of the direct techniques. Due to this, the suitable similarity transformations are deployed to reduce the dimensional complexity of the constructed partial differential equations. A robust Matlab-based bvp4c scheme is utilized as a basic tool to produce the similarity solutions of the governing equations. The computer generated numerical data is presented in view of flow, temperature and concentration profiles including physical quantities of interest like skin-friction coefficient, heat and mass transport rates for the various values of physical parameters range such as, 0 ≤ M ≤ 1 , 0 ≤ β ≤ 1 , − 0.3 ≤ λ ≤ 0.6 , − 0.2 ≤ Q ≤ 0.2 , 0 ≤ Ec ≤ 2.2 , 1.2 ≤ Pr ≤ 2.2 , 0 ≤ Sr ≤ 0.5 and 1.2 ≤ Sc ≤ 2.2 . Accordingly, it is noticed that, enhancing magnetic parameter decreases the Maxwell fluid flow and amplifies the temperature and concentration fields. Enlarging Maxwell fluid parameter decreases the velocity field and increases the temperature and concentration profiles. Amplified slip parameter diminished the Maxwell flow inside the flow regime. Increasing heat source/sink parameter amplifies the temperature field. Further, magnifying Soret number amplifies the concentration field. Magnitude of skin-friction coeffiecient enlarged with amplified magnetic and Maxwell fluid parameters. Heat and mass transport rates decayed with enhancement in heat source/sink and Soret parameters. Finally, it is described that, the present similarity solutions showing good agreement with the previously reported solutions in the literature and this fact confirms the accurateness of the used numerical method and the generated similarity solutions.

Numerical heat and mass transfer in magnetized Williamson liquid motion over a sensor wall engulfed in a micro-cantilever system: An application to thin-film fluidic cells

Central focus of this numerical analysis is to investigate the influence of magnetic body force and thermal radiation on the time-dependent electrically conducting two-dimensional viscous incompressible boundary layer flow of non-Newtonian Williamson fluid over a microcantilever sensor surface suspended in a squeezed regime numerically. A novel heat source/sink and Soret effects are included in the respective governing equations. The constructed time-dependent nonlinear coupled partial differential equations are solved by using a bobust RK-4 technique. Increasing magnetic number increases the velocity distribution and decreases the temperature and concentration profiles in the flow regime.Enhancing Soret number increases the mass diffusion profile. Increasing magnetic number suppress the skin-friction coefficient. Heat transport rate booted with rising radiation number and Sherwood number decreased with enlarged Schmidt number in the channel regime. Finally, the numerical accuracy of the present similarity solutions and used numerical method is validated with existing results and observed a remarkable agreement.

An MHD nanofluid flow with Marangoni laminar boundary layer over a porous medium with heat and mass transfer

ABSTRACT The current work considers two-dimensional incompressible fluid flow with heat transfer over a porous medium with mass transpiration and Marangoni boundary condition. The nanoparticles of graphene are mixed in water to improve thermal efficiency. It behaves as a heater upon increasing its solid volume fraction, Eckert number, and as a cooler upon increasing suction. This flow has remarkable interest due to its applications in glues, silicon wafers, heat exchangers, paints, crystal growth in space, etc. The ordinary differential equations (ODEs) are obtained from the considered partial differential equations (PDEs) using similarity transformation technique. Then the solutions are analytically recovered from the system of ODEs. The solutions of temperature and concentration fields are obtained in terms of Laguerre polynomial. The impacts of different parameters, such as Marangoni number, inverse Darcy number, Prandtl number, and Eckert number are analysed using graphical observations. Specially mentioned is Marangoni convection, which contains many industrial and engineering applications such as in nanotechnology, atomic reactors, soap films, semiconductor processing, and atomic reactors. This work adds the effect of graphene water nanofluid which enhance the thermal efficiency in a better way than the base fluid and explains the physical problem on the basis of chemically radiative Marangoni flow.

A numerical investigation of the two-dimensional magnetohydrodynamic water-based hybrid nanofluid flow composed of Fe3O4 and Au nanoparticles over a heated surface

Abstract In this research article, the viscous, steady, and incompressible two-dimensional hybrid nanofluid flow composed of Fe3O4 and Au nanoparticles on an extending sheet has been presented. An inclined magnetic field impact is used for evaluating the impacts of various factors in that case. Furthermore, the influences of porosity, Brownian motion, thermophoresis, thermal and space-dependent heat sources, and thermal radiation factors are also used in this work. The numerical analysis is done by using the bvp4c technique. Validation of the present results confirms that the present analysis is valid. The outcomes show that the higher magnetic factor reduces velocity distribution while increasing the frictional force at the surface due to Lorentz forces which oppose the fluid flow. The friction force at the sheet’s surface is higher when the sheet stretches as compared to the case when the sheet shrinks. Increase in the magnetic factor increases the skin friction of sheet’s surface which consequently increases the rate of thermal transmission at the surface along with thermal distribution. The higher values of thermal radiation and thermal-dependent heat source increase the thermal transportation rate of sheet’s surface. Insights from this investigation can improve electronics cooling systems, vital for devices prone to overheating. Optimizing heat transfer with magnetohydrodynamic water-based hybrid nanofluids containing Fe3O4 and Au nanoparticles ensures efficient heat dissipation, enhancing device performance and longevity.

Irreversibility analysis for unsteady slip flow of heat absorptive liquid with multiple mass diffusion of nanomaterials over a permeable vertical moving plate: A comparative study

This study looks at how thermal radiation and magnetic fields affect the generation of entropy in the unsteady flow of a tri-hybridized nanofluid across a plate that is moving vertically and has surface slippage and suction that changes over time. The movement of the plate aligns with fluid flow, and the far-away velocity increases exponentially following the small perturbation rule. The unsteadiness of the flow is attributed to the varying free stream velocity. A homogeneous magnetic flux acting transversely to the porous wall regulates the laminar and incompressible two-dimensional flow. The presence of tri-hybridized nanoparticles makes it possible to study how adding nanoparticles with different thermal properties, such as Cu, Fe3O4 and TiO2 changes the way base fluids like water and kerosene flow and how heat moves through them. Using dimensionless variables, the mathematical model of the problem is transformed into a form amenable to an analytical solution. The solution is achieved with the help of two-term harmonic and non-harmonic functions. Several factors that influence fluid flow and heat transmission are examined and explored in depth. These include plate velocity, slippage parameter, nanoparticle volume fraction, thermal radiation and heat absorption. The findings show that ternary nanoparticles raise the temperature and speed of both water and kerosene more than hybrid nanoparticles. The increase in the volume fraction of nanomaterials also increases the temperature and velocity of both fluids. These results might be used to improve the efficiency of thermal management systems in a wide range of technical and industrial operations having heat transfer and fluid movement.

A numerical study of thermal and diffusion effects on MHD Jeffrey fluid flow over a porous stretching sheet with activation energy

The primary aim of this research work is to develop a mathematical model for the two-dimensional steady incompressible flow of a Jeffrey fluid over a vertical stretching sheet immersed in a Darcy porous medium. The combined effects of Soret and Dufour numbers, activation energy, viscous dissipation, thermal radiation, mixed convection, and Joule heating are included in the energy and concentration equations within this model. Using appropriate similarity variable transformations, the governing partial differential equations were altered into nonlinear ordinary differential equations and then solved numerically using the Runge-Kutta-Fehlberg method along with the shooting technique. The impact of various physical parameters on concentration, velocity, and temperature profiles is deployed through graphs. The velocity increased with a gradual increment in the values of the viscous ratio, thermal, and solutal stratification parameters, whereas the reverse trend was noticed for the magnetic strength. The temperature diminishes as the Prandtl number increases, whereas the opposite scenario exists for Eckert and Dufor numbers and radiation. The fluid concentration rises for a monotonic increment of the Soret number, while it reduces as the Schmidt number, activation energy, and reaction constraint escalate. The amplification of skin friction is observed with an increase in magnetic field strength, while it decreases with an increasing viscous ratio factor. The Nusselt number decreases as radiation increases and the Eckert number rises, but the opposite scenario occurs with increases in the Prandtl number. The Sherwood number is heightened by an increase in the Schmidt number, reaction, and activation energy factors. Moreover, the numerical values of skin friction and the Nusselt number are compared with the previously published work, demonstrating excellent agreement between the results.

Illustration of thermal radiation on the mixed convection of Williamson nanofluid over an inclined cylindrical surface

This study emphasizes the two-dimensional incompressible flow of Williamson nanofluid caused by an inclined, infinite, expanding/contracting cylinder that is inclined at an angle with the horizontal axis. The focus is on the behavior of non-Newtonian fluid on the flow, heat, and mass transfer during the process. The properties of the fluid are modeled using a set of partial differential equations in association with the characterizing parameters obtained during the presentation of non-dimensional form. The problem is solved numerically using the shooting-based Runge–Kutta fourth-order technique. The results are shown graphically for the behavior of the several contributing parameters. The effect of various pertaining parameters is analyzed henceforth. The physical quantities of interest are also discussed in the tables. The study provides useful insight into the behavior of the fluid, i.e. suction/injection shows opposite behavior on the fluid velocity profiles where suction decelerates the profile and injection enhances it significantly.

Modal analysis for incompressible fluid flow

This paper presents a numerical method for incompressible fluid flow. A difficulty in analyzing incompressible fluid flow is that the continuity equation has no time evolution term. In the marker and cell (MAC) method, Poisson’s equation is solved iteratively, which takes most of the computation time, and in the artificial compressibility method (ACM), pseudo-time iteration is necessary to solve for unsteady solutions. Here, modal analysis that uses the velocity eigenvectors corresponding to zero eigenvalues is proposed for analyzing two-dimensional incompressible fluid flow. The proposed method involves only about one third of the number of variables needed in the MAC method and the ACM, and it does not require iterative calculation of Poisson’s equation or pseudo-time iteration. Numerical results for a simple flow system and a cavity flow obtained using the proposed method are compared with those obtained using the ACM and the simplified MAC method. The results agree well, thereby validating the proposed modal analysis.

NUMERICAL STUDY OF CARREAU FLUID FLOW ALONG AN EXPONENTIAL CURVED STRETCHING SURFACE

A two-dimensional incompressible boundary layer Carneau fluid flow with heat-transfer analysis over a curved stretching surface is analyzed. The energy equation with the inclusion of thermal radiation and viscous dissipation effects is considered. The governing partial differential equations which govern such flow phenomena are transformed into suitable form of ordinary differential equations for integration by using stream function formulation. The developed non-linear problem has been solved by computational approach based on shooting technique using sixth-order Runge-Kutta method and Matlab built-in function bvp4c program. The effects of non-dimensional controlling parameters on temperature and velocity profile are analyzed with the aid of tables and figures. The surface drag force and Nusselt numbers are studied for the different values of the governing parameters. It is predicted that velocity of the fluid and boundary layer thickness is decreased when radius of curvature parameter δ is increased. Furthermore, the temperature profile dwindles for the growing values of δ. Other important information is that for shear-thinning fluid the velocity profile shows its increasing nature, whereas for shear-thickening fluid the opposite trend has been observed. For increasing values of curvature parameter δ from 2 to 1000, the temperature distribution and velocity profile is decreased. The radiative heat flux is included to enhance the temperature of the system, so, for the increasing values of radiation parameter <i>R<sub>d</sub></i> from 0.2-0.5 the temperature distribution is increased. Further, as the Biot number and Eckert number are increased from 0.2-2 and 0.1-1, respectively, the temperature distribution is increased.

Bifurcation analysis of double cavity flows

The first few bifurcations in a two-dimensional incompressible double cavity flow are investigated using the linear stability analysis, the Floquet analysis, and the nonlinear direct numerical simulations (DNS). The prediction of the critical Reynolds number and the type of bifurcation (Hopf, pitchfork, inverse pitchfork, and Neimark–Sacker), which depend on cavity configuration, by the linear stability analysis and the Floquet analysis is consistent with nonlinear DNS. The nonlinear DNS results show that the state of the system passes through multiple intermediate (unstable) states before it reaches the stable attractor (heteroclinic chain), and the type of intermediate states depends on initial conditions. The intermediate states are reported as the asymptotic state in the literature for some flow conditions because it is not known a priori how long it will take to reach the asymptotic state in nonlinear simulations. The present study reports the actual asymptotic state for those flow conditions.

A conservative sharp interface method for two-dimensional incompressible two-phase flows with phase change

A conservative sharp interface method is proposed in this work to simulate two-dimensional/axisymmetric incompressible two-phase flows with phase change. In this method, we use the cut cell method to generate unstructured meshes near the interface, of which the cell edges overlap with the interface at each time step. On such mesh, the mass and heat transfer during phase change and all the jump conditions can be incorporated into the calculation of fluxes at the cell edges, to ensure that they are strictly satisfied at the interface in a sharp manner. The governing equations, including the incompressible Navier–Stokes equations, heat equation, and vapor mass fraction equation, are discretized by a second-order finite volume method in the arbitrary Lagrangian–Eulerian framework. To well couple the mass, heat, momentum, and interface evolution, the solution procedure is carefully designed and performed with several techniques. In such a way, the sharp discontinuity of the velocity, stress, temperature gradient, and vapor fraction, caused by the mass/heat transfer during phase change, can be simulated accurately and robustly. The performance of this method is systematically examined by cases of phase change at or below the saturated temperature, including vapor bubble in superheated liquid, film boiling, droplet evaporation at different relative humidity conditions, droplet evaporation under gravity, and droplet evaporation under forced convection. The applicability of the present method for incompressible two-phase flows with phase change is well demonstrated by comparing the numerical results with the benchmark, theoretical or experimental ones.

Numerical simulations of two-dimensional incompressible Navier-Stokes equations by the backward substitution projection method

The backward substitution method is a newly developed meshless method that has been used for the simulation of many problems in science and engineering with high accuracy and efficiency. In this paper, we explore the feasibility of employing the backward substitution method for simulating two-dimensional incompressible flows. Two non-increment pressure correction projection methods are considered to decompose the original velocity and pressure coupling system into two boundary value problems of intermediate velocity and pressure. Then, two boundary value problems are solved by the backward substitution method in each time iteration step. Five numerical examples are provided to demonstrate the accuracy, computational efficiency and convergence of the method. Comparisons with some existing meshless methods verify the method's advantages and potential applications to engineering.

Darcy resistant of Soret and Dufour impact of radiative induced magnetic field sutterby fluid flow over stretching cylinder

The incompressible two-dimensional steady flow of Sutterby fluid over a stretching cylinder is taken into account. The magnetic Reynolds number is not deliberated low in the present analysis. Radiation and variable thermal conductivity are considered to debate the impact on the cylindrical surface. The Dufour and Soret impacts are considered on the cylinder. The mathematical model is settled by employing boundary layer approximations in the form of differential equations. The system of differential equations becomes dimensionless using suitable transformations. The dimensionless nonlinear differential equations are solved through a numerical scheme(bvp4c technique). The flow parameters of physical effects on the velocity, temperature, heat transfer rate, and friction between surface and liquid are presented in tabular as well as graphical form. The velocity function declined by improving the values of the Sponginess parameter. The fluid temperature is reduced by increment in curvature parameter.

Optimization of Magnetohydrodynamic Parameters in Two-Dimensional Incompressible Fluid Flow on a Porous Channel

Optimization of Magnetohydrodynamic Parameters in Two-Dimensional Incompressible Fluid Flow on a Porous Channel

Weakly viscous two-dimensional incompressible fluid flows using efficient isogeometric finite element method

This paper presents a straightforward and efficient numerical simulation method for solving the Navier–Stokes equations for weakly viscous incompressible fluids describing steady flow. Our approach utilizes isogeometric finite elements to handle higher-order partial differential operators associated with weakly viscous incompressible flow problems. Specifically, our numerical formulation employs a principle of virtual power (PVP)-based weak formulation that utilizes a stream-function field, which distinguishes it from the more commonly used bi-harmonic type formulations. The usage of a stream-function field ensures a pointwise divergence-free velocity condition, making the present method suitable for low to moderately high Reynolds number flow problems. In contrast to the bi-harmonic formulation, which is typically used for describing internal flow and requires special treatment of outflow boundary conditions, the PVP-based formulation is more general and does not require special treatment at the outflow boundary. It is also demonstrated that both bi-harmonic and PVP-based weak formulations yield identical results for internal flow problems. Our method employs non-uniform rational B-spline basis functions, and we present a simple stitching technique for imposing no-slip Dirichlet boundary conditions. Finally, we solve Poisson's equation to recover the pressure field. Furthermore, we use an appropriate Gaussian quadrature that is exact for splines to speed up the computation of various element matrices, especially for high polynomial degrees. The proposed formulation is evaluated by solving a set of numerical problems, including internal flow and channel flow problems.

Identification of vortex boundaries in two-dimensional incompressible flows based on the Liutex-shear interaction

Identification of vortex boundaries in two-dimensional incompressible flows based on the Liutex-shear interaction

A Gaussian–cubic backward substitution method for the four-order pure stream function formulation of two-dimensional incompressible viscous flows

A Gaussian–cubic backward substitution method for the four-order pure stream function formulation of two-dimensional incompressible viscous flows

Cattaneo-Christov heat and mass transmission of dissipated Williamson fluid with double stratification

The vast significance and applications in various industrial works such as heat and cooling process, chemical reactors, food storage systems and several medical works motivated the author to conduct this type of study. The aim of this paper is to inspect the two-dimensional incompressible magnetohydrodynamic flow of Williamson fluid through a stretching sheet. The Cattaneo-Christov temperature and concentration flow is considered with the effects of double stratification and viscous dissipation. The leading nonlinear partial differential equations of flow are transformed into ordinary differential equations by means of renowned similarity transformations and the solutions of flow problem are obtained by means of bvp4c method on MATLAB software. The Williamson fluid parameter depending on time relaxation and declines the fluid motion. The motion of fluid slowed down due to Hartman number. The mass and heat flow is noted to be decline due to thermal and solutal relaxation parameters. The rises in stratification coefficient reduce the mass and heat transferal rate.