Flow Of Newtonian Fluid Research Articles

Dynamical dissipative and radiative flow of comparative an irreversibility analysis of micropolar and hybrid nanofluid over a Joule heating inclined channel

This report scrutinized the influence of radiation and Ohmic heating on the dissipative flow of micropolar and hybrid nanofluid within an inclined length 2h channel under convective boundary conditions. Primary flow equations are renewed as the system of NODEs with the assistance of proper similarity conversions. In two circumstances, hybrid fluid flow and micropolar fluid flow, a blend of shooting and Runge–Kutta 4th order strategy, is used to achieve the desired results. The critical consequences of the current study are Larger pressure gradient minimizes the fluid velocity, and a more significant inertia parameter minimizes the rotation profile in the case of Newtonian fluid flow but facilitates the same in the case of hybrid nanofluid flow. It is perceived that the escalation in Brinkmann number causes the amelioration in the fluid temperature, and the radiation parameter mitigates the same. Furthermore, it is discovered that the Grashoff number enhances the Bejan number at the centre of the channel but lessens the same at other areas. Finally, validation is executed to compare the current outcomes with the former results and perceive a good agreement.

The effect of polyethylene butene (PEB) and xylene on the shear stress of Niger delta crude oil

Crude oil production and transportation is plagued by several flow assurance issues especially in offshore environment with prevailing low temperature. One of the flow assurance challenges is the deposition of paraffin wax which usually changes the crude oil flow from Newtonian fluid flow to non- Newtonian fluid flow with increased viscosity. This increased viscosity can impede flow causing the installation of high horsepower pumps for fluid flow. In severe cases, paraffin wax has plugged the pipes and caused production disruption. It is therefore imperative to manage paraffin disposition in crude samples containing paraffin compounds (C18+). This research discusses the use of varying concentrations of Polyethylene Butene (PEB) in managing wax precipitation at various temperatures (10 °C to 35 °C) at a constant shear rate of 511(s-1). The reduction in crude oil temperature increased the shear stress in all experiments conducted. It was discovered that the increasing concentration of PEB from 500ppm to 5000ppm had a sinusoidal effect on reducing the shear stress. 500ppm of PEB effected a 19% reduction in shear stress, while 5000ppm effected a 35% reduction in shear stress. It is important for the engineer to make the choice of inhibitor concentration based on the degree of shear stress reduction required to optimize inhibitor usage.

Numerical modeling of generalized Newtonian fluids flow in S-type geometry of bypass

This paper deals with a numerical simulation of the blood flow in bypass geometry, which consists of a main tube with a narrowing and its bridging by a bypass. Two different geometries of the bypass are considered, namely the classical bypass of the narrowed place and the second variant is the so-called S-type bypass. The optimal value of the connection angle of the bypass graft to the main channel is the subject of numerical testing in this work. Attention is focused on the values between 45 and 60 degrees. For the blood flow three relevant models are considered, namely Newtonian, Carreau and Power Law models. The numerical results are obtained using OpenFOAM and they are compared for all the considered types of geometry and for all values of the bypass connection angle and selected rheological viscosity models.

Reduced order modeling for parametrized generalized Newtonian fluid flows

Non-Newtonian fluids are present in most manufacturing industry processes. Computational models used to describe the rheological behavior of such materials can be costly due to the non-linear behavior of the viscosity. This work presents a parametrized projection-based model reduction approach to address time-dependent generalized Newtonian fluids in a computational framework. We develop our discrete formulation using three ingredients: an offline-online setting for the model reduction based on a proper orthogonal and Tucker decompositions, the finite element method for the discretization of the spatial domain and finite differences for the temporal integration, and the variational multiscale approach as a stabilization technique for both the full and reduced order models. We also evaluate the reduced method with some numerical tests, where the first part involves testing the accuracy of the model reduction method for time as a single parameter of the dynamic reduced problem. The second part involves the solution of parametrized time-dependent reduced problems with the Reynolds number and the power-law index of the fluid as the varying parameters.

Effect of heat transfer on peristaltic flow of Newtonian fluid through eccentric cylinders

Heat transfer effect on peristaltic Newtonian flow in an annular region of eccentric cylinders is considered. An approximate solution for temperature and velocity is obtained using perturbation technique. For constant flow rate, the variation of pressure gradient and velocity with respect to several non-dimensional parameters is studied using graphical representation. It is seen in these graphs that velocity, pressure gradient and temperature enhance with raise in eccentricity and amplitude ratio. Heat diffuses with faster rate with depletion in area of cross section eccentric annulus through parameter inner cylinder radius. Also, velocity rises with increase in heat transfer parameters such as Grashof number and heat transfer co-efficient. Thus velocity of peristaltic flow in eccentric annulus enhances rapidly in presence of heat transfer compared to absence of heat transfer. A study of peristaltic flow in concentric annulus in presence of heat transfer is obtained analytically and compared with present study at eccentricity equal to zero, to validate the approximate solution. It is seen that flow rate increases more in case of eccentric annulus compared to concentric in presence of heat transfer. Present study has application in endoscope, which is important to diagnose problems in internal organs. Also, the variation of pressure gradient helps to maintain flow rate which is essential during insertion of catheter into artery.

Numerical simulations of MHD generalized Newtonian fluid flow effects on a stretching sheet in the presence of permeable media: A finite difference-based study

Casson–Williamson (CW) nanofluid flows and mass transfer characteristics are explored in this study. Furthermore, the velocity slip condition and viscous dissipation affect or are taken to examine the changes in mass and heat transfer caused by a stretching surface integrated into permeable media with heat conversion beneath the effect of a magnetic field and consistent thermal radiation. All the physicochemical characteristics of the non-linear fluids are regarded massive. Whether or not the concentration of nanofluids remains stable is investigated. When particles of a nanofluid are in motion, chemical reactions can occur, and this motion can be used to study the concentration of the nanofluid. One must first examine a set of non-linear partial differential equations with boundary conditions as a base equation to obtain the necessary BVP mathematical model. The approximate solution for differential equations was found using the finite difference method, which also considered the necessary boundary conditions. The numerical analysis results are then represented visually to demonstrate how different governing parameters affect velocity, temperature, and concentration. Although the heat transmission exhibits a reverse manner, the non-Newtonian nanofluid moves more quickly in the non-appearance of a magnetic domain than it does in one. Additionally, as the porosity parameter increased, the heat transmission rate decreased, whereas the skin friction coefficient increased. The novel parts of this study come from the simulation findings of a non-Newtonian CW nanofluid model in porous media subjected to a magnetic field, heat radiation, and slip velocity phenomena.

Experimental Investigations on Geometry Modulated Solute Mixing in Viscoelastic Media

In this study, geometrically modified microchannels fabricated using a stereolithography technique are employed to analyze micromixing of polymeric solutions. Experimental and numerical analyses were conducted to evaluate the qualitative and quantitative validity of the Newtonian fluid flow inside the geometrically modified channels. An in-house image processing code was used to analyze the dye concentration distributions resulting from complex fluid transport and mixing within the modified channels. Our analysis illustrates the existence of inertio-elastic instability in the geometrically modified microchannels for the transport of viscoelastic fluids. In addition, the presence of inertio-elastic instability significantly enhances the mixing efficiency as a result of the interaction between viscoelasticity and modified channel geometry. This analysis provides important physical insights into the cost-effective design and operation of microfluidic devices that handle viscoelastic fluids, which could be useful in designing and analyzing a passive micromixer that transports bio/polymeric fluids.

Hydrodynamic and rheological characteristics of a pseudoplastic fluid through a rotating cylinder

The fully developed turbulent flow of pseudoplastic ( ) and Newtonian fluids in an isothermal axially rotating cylinder has been carried out using a large eddy simulation (LES) with an extended Smagorinsky model. The simulation Reynolds number of the present predictions has been assumed to be at various rotation rates This investigation seeks to assess the influence of the centrifugal force induced by the swirl on the mean flow quantities, turbulent statistics, and instantaneous turbulence structure to describe the rheological behavior and the turbulence features. The predicted results indicate that with increasing rotation rate, the pseudoplastic fluid tends to behave like a liquid when approaching the pipe center due to the lower apparent fluid viscosity in the logarithmic region as the pipe wall rotates. Moreover, the reduction in the pseudoplastic apparent viscosity in the core region induces a pronounced increase in the axial velocity profile further away from the pipe wall toward the core region. It is interesting to note that the growth of the centrifugal force induced by the swirl driven by the rotating pipe wall results in an apparent attenuation in turbulence intensities of the axial velocity fluctuation and, consequently, in the kinetic energy of turbulent fluctuations and the turbulent Reynolds shear stress of the axial-radial velocity fluctuations, as the pipe wall rotates. Moreover, the increased rotation rate leads also to a noticeable increase in the Root mean square (RMS) of the radial and tangential fluctuations. It can be said that the transport mechanism of turbulence intensities from the axial components to the other ones exhibits a marked increase with increasing pipe wall rotation.

Analysis of Entropy Production of Immiscible Micropolar and Newtonian Fluids Flow through a Channel: Effect of Thermal Radiation and Magnetic Field

Analysis of Entropy Production of Immiscible Micropolar and Newtonian Fluids Flow through a Channel: Effect of Thermal Radiation and Magnetic Field

Navier-Stokes Solutions for Accelerating Pipe Flow—A Review of Analytical Models

This paper reviews analytical solutions for the accelerated flow of an incompressible Newtonian fluid in a pipeline. This problem can be solved in one of two ways according to the (1) imposed pressure gradient or (2) flow rate. Laminar accelerated flow solutions presented in a number of publications concern cases where the two driving mechanisms are described by simple mathematical functions: (a) impulsive change; (b) constant change; (c) ramp change, etc. The adoption of a more complex and realistic description of the pressure gradient or flow rate will be associated with a profound mathematical complexity of the final solution. This is particularly visible with the help of the universal formula derived by several researchers over the years and discussed in this paper. In addition to the solutions strictly defined for laminar flow, an interesting extension of this theory is the theory of underlying laminar flow for the analysis of turbulent accelerated pipe flows (TULF model developed by García García and Alvariño). The TULF model extends the Pai model developed more than 60 years ago, which has been previously used for steady flows only. The discussed solutions extend the theory of analytical solutions of simplified two-dimensional Navier–Stokes equations and can be used not only to study the behavior of liquids during accelerating pipe flow but they can also be used to test the accuracy of commercial CFD codes.

INFLUENCE OF MAGNETIC FIELD ON THE FLOW OF JEFFERY AND NEWTONIAN FLUIDS THROUGH COMPOSITE POROUS CHANNEL

This work concerns the flow of Jeffery and Newtonian fluids through a composite porous channel in the presence of a uniform magnetic field applied perpendicular to the direction of flow. The mathematical formulation of this problem represents the flow of Jeffery fluid through the porous channel sandwiched between two porous channels of the Newtonian fluid. The horizontal composite porous channel is divided into three porous channels of the same width and the fluid flow occurs due to a constant pressure gradient. The Jeffery equation has been used for the middle porous channel while the Brinkman equation has been employed for lower and upper porous channels. Continuity of velocities, continuity of stresses at interfaces, and impenetrability conditions at the outer surface of the composite porous channel have been used as boundary conditions. Analytical expressions for velocities, volumetric flow rate, and shear stresses are obtained for the respective channels. Effects of the viscosity ratio parameter (β), Hartmann number (<i>M</i>), Jeffery parameters (λ<sub>1</sub>), and permeability parameters (η) on the flow rate and fluid velocity are explained graphically and discussed. Numerical values of volumetric flow rate with respect to different flow parameters such as Hartmann number, viscosity ratio, and Jeffrey parameter are presented in tabular form.

A Computational Analysis Unsteady Incompressible Newtonian Fluid Flow and Heat Transfer in a Cylindrical Pipe Filled with Porous Media Via the Collocation Approach

In this study, the problem of unsteady incompressible flow was analyzed using collocation technique to find the most accurate solution for the velocity and energy distribution of the Newtonian fluid flow. The flow experienced a gradual decrease with a retarded flow and afterwards increases but not a steady increase. It is revealed that a little increase in the Darcy number leads to an increase in the velocity of the fluid flow, indicating that porosity increase enhances the fluid flow. Results further show that increase in the Hartman parameter decreases the fluid velocity which is due to the strength the Lorentz force. Temperature decreases with increase in the Prandtl number and the Brinkman parameter.

Effect of obstacles on turbulent flows in a rectangular channel from their front sides

In this piece, the impact of an obstacle's upstream edge inclination in a rectangular channel is investigated. The main purpose of this study is to give a better understanding of this associated phenomenon by reflecting more accurately the different cooling techniques and to get as close as possible to real conditions of use. This study is based on the laws of conservation of mass, momentum, and energy, the equations are given in the case of the 2-D flow of an incompressible Newtonian fluid, depending on the variables primitives given below. During the study, we used the FLUENT computer code, as well as its GAMBIT mesh generator several times, which allowed us to become more familiar with numerical simulation. The purpose of our numerical research is to clarify physical phenomena that are described by theory without using more expensive experimentation.

Multiphase flow of Newtonian fluid sandwiched between non-Newtonian fluids through a composite porous channel

Multiphase flow of Newtonian fluid sandwiched between non-Newtonian fluids through a composite porous channel

Numerical Analysis of Transfer of Heat by Forced Convection in a Wavy Channel

Convective heat transfer of laminar forced convection in a wavy channel is studied in this paper. Numerical simulations of the 3D steady flow of Newtonian fluid and heat transfer characteristics are obtained by the finite element method. The effects of the Reynolds number (10 ≤Re≤1000), number of oscillations (0 ≤N≤5) and amplitude of the wall (0.05 ≤A≤0.2) on the heat transfer have been analyzed. The results show that the average Nusselt number is elevated as the Reynolds number is raised, showing high intensity of heat transfer, as a result of the intensified effects of the inertial and zones of recirculation close to the hot wavy wall. The rate of heat transfer increases about 0.28% with the rise of the number of oscillations. In the transfer of heat along a wavy surface, the number of oscillations and the wave amplitude are important factors. With an increment in the number of oscillations, the maximal value of the average velocity is elevated, and its minimal value occurs when the channel walls are straight. The impact of the wall amplitude on the average Nusselt number and dimensionless temperature tends to be stronger compared to the impact of the number of oscillations. An increase of the wall amplitude improves the rate of heat transfer about 0.91% when the Reynolds number is equal 100. In addition, when the Reynolds number is equal 500, the rate of heat transfer grows about 1.1% with the rising of the wall amplitude.

Insight into the relationship between non-linear mixed convection and thermal radiation: The case of Newtonian fluid flow due to non-linear stretching

The current research focuses the light on the characterization of buoyancy-driven non-linear mixed convection and non-linear radiation in a Newtonian flow over a non-linearly stretching vertical sheet, and this type of flow has useful applications in many industrial processes, such as the paper and pulp industry, polymer industry, electronic device cooling, solar collectors, gas turbine plants, and nuclear power. Using appropriate transformations, governing PDEs for non-linear mixed convection are reduced to higher-order non-linear ODEs and those are numerically solved. Along with tabular presentations of computed results, the graphical representations are generated to elucidate the effects of involved parameters on convection transport properties and their inter-relations. It demonstrates that flow velocity increases near the surface and decreases away from the surface as the non-linear convection parameter increases. Furthermore, increments in the thermal buoyancy, temperature ratio and non-linear radiation parameters result in the boost of velocity. The temperature decreases as linear and non-linear buoyancy-related parameters (non-linear convection and thermal buoyancy parameters) are of higher levels. In contrast, the temperature rises with two non-linear thermal radiation-related parameters (thermal ratio and non-linear radiation parameters). For greater values of the non-linear stretching related parameter, a lower velocity and a higher temperature are witnessed. The non-linear convection, thermal buoyancy, thermal ratio and non-linear radiation parameters contribute toward the reduction of the magnitude of surface-drag force and growth of the surface cooling rate. But, with the non-linearity in surface stretching there are significant percentage hikes of surface-drag force magnitude and surface cooling rate.

Numerical Study for the Performance of Viscoelastic Fluids on Displacing Oil Based on the Fractional-Order Maxwell Model.

In the study of polymer flooding, researchers usually ignore the genetic stress properties of viscoelastic fluids. In this paper, we investigate the process of viscoelastic fluid flooding the remaining oil in the dead end. This work uses the fractional-order Maxwell in the traditional momentum equation. Furthermore, a semi-analytic solution of the flow control equation for fractional-order viscoelastic fluids is derived, and the oil-repelling process of viscoelastic fluids is simulated by a secondary development of OpenFOAM. The results show that velocity fractional-order derivative α significantly affects polymer solution characteristics, and increasing the elasticity of the fluid can significantly improve the oil repelling efficiency. Compared to the Newtonian fluid flow model, the fractional order derivative a and relaxation time b in the two-parameter instanton equation can accurately characterize the degree of elasticity of the fluid. The smaller the a, the more elastic the fluid is and the higher the oil-repelling efficiency. The larger the b, the less elastic the fluid is and the lower the cancellation efficiency. Moreover, the disturbance of the polymer solution to the dead end is divided into two elastic perturbation areas. The stronger the elasticity of the polymer solution, the higher the peak value of the area in the dead end and the higher the final oil displacement efficiency.

Mathematical model of the process of mixing and separation in a microfluid channel with five outlets

The article presents the results of mathematical modeling in a two-dimensional formulation of the mixing process by mutual diffusion and separation of flows of Newtonian fluids in a microfluidic mixing channel with five outlets. Branches are used to separate flows into fractions with a given concentration of one of the components in the mixture. The diffusion process occurs in a laminar flow regime, without chemical and thermal interaction. The mixture flow model was set up in a two-dimensional formulation. One component of the mixture flows through the main channel 1 mm wide, then at a distance of 5 mm from the entry point to the channel perpendicular to it, there are two more entrances also 1 mm wide, through which the second component is fed. At the outlet, there are five taps with dimensions of 0.2 mm to take the mixture of the desired concentration. Four outlets for the intake of the mixture are located opposite each other in pairs. Liquids with the physical characteristics of water and ethyl alcohol were taken as miscible components. The problem was solved using the ANSYS-Fluent software package.

Enhanced turbulent convective heat transfer in helical twisted Multilobe tubes

Enhancing heat transfer performance has been the main interest in the thermal engineering field. Various enhancement methods have been proposed, including twisted and Multilobe tubes. Nevertheless, no study investigating the enhancement by combining both strategies has been reported. This study is thus conducted to numerically evaluate the turbulent convective heat transfer performance of Newtonian fluid flow in a helical twisted Multilobe tube. The model is validated against experimentally measured data of similar configurations. The effects of Multilobe geometries and Reynolds number were evaluated. The results revealed that combination of twisting and Multilobe profile enhance the secondary flow and, in turn, increases the convective heat transfer performance for straight geometries by up to 6.76%, while the addition of twisting of the tubes has a marginal effect on the heat transfer performance in helical models. Furthermore, the variation of the number of lobes does not lead to significant changes in the heat transfer performance (less than 2% difference). Overall, bilobe cross-section shows superior performance in terms of overall performance when it is combined with a helical tube (1.08) or twisting (1.002) only, while pentalobe cross-section has better performance index in sophisticated flow with both helical tube and twisting of tube (1.037). Additionally, correlations are developed to predict the friction factor and Nusselt number in straight and helical tube. To find optimum configurations, Neural Network (NN) models are developed based on the CFD result. By using multi objectives optimization, it was found that the circular straight pipe configurations with and without a twist are the ones closest to the optimum solutions. Meanwhile, helical pipe without a twist is the closest to the optimum solutions. These observations are aligned with the insights obtained from the CFD analysis.

NUMERICAL MODELLING OF A NON-LINEAR RADIATIVE NON-NEWTONIAN NANOFLUID FLOW WITH ARRHENIUS ACTIVATION ENERGY

This research has examined the flow properties of non-linear radiative nano non- Newtonian fluid flow via a stretched sheet, as well as the impact of Arrhenius activation energy is also inspected. The basic equations, which comprised time-dependent pivotal equations, were built using boundary layer approximations. As a numerical methodology, an explicit finite difference (EFD) technique was exerted. The fluid flow has been simulated employing FORTRAN in this case. A stability and convergence study has been performed to determine the accuracy of the numerical approach, and the system was determined to be converged at Pr≥ 0.062, and Le≥ 0.016. Here, non-dimensional outcomes based on various physical characteristics are considered. The effect of these numerous physical characteristics is explained and visually represented for a variety of flow fields. Furthermore, the examination of streamlines and isothermal lines has demonstrated enhanced visualization of the fluid flow. It has been revealed that non-linear pattern thermal radiation has a substantial impact on the heat transfer properties of nanofluid. Moreover, when non-linear radiation is addressed, the Lorentz force also has a significant impact on fluid flow. A great agreement has also served as a confirmation of the current effort. This sort of fluid has potential uses in mining, lubrication, and biomedical flow.