Fluid Mass Transfer Research Articles

A study of heat and mass transfer of Non-Newtonian fluid with surface chemical reaction

Considering the significance of non-Newtonian fluid usage in manufacturing such as molten plastics, polymeric materials, pulps, and so on, significant efforts have been made to investigate the phenomenon of non-Newtonian fluids. In this article the influences of heat and mass transfer on non-Newtonian Walter's B fluid flow over uppermost catalytic surface of a paraboloid is encountered. An elasticity of the fluid layer is considered in the freestream together with heat source/sink and has the tendency to cause heat flow in the fluid saturated domain. The flow problem of two-dimensional Walter's B fluid is represented using Law of conservation of mass, momentum, heat, and concentration along with thermal and solutal chemical reactive boundary conditions. The governing equations are non-linear partial differential equation and are non-dimensionalized by employing stream function and similarity transformation. The final dimensionless equations yielded are coupled non-linear ordinary differential equations. Furthermore, shooting technique along with RK-4th order method is used to get the numerical results. Graphs and tables are modeled by using MATLAB software to check the effects of Walter's B parameter, Chemical reaction parameter and Thickness parameter on temperature, velocity, and concentration profiles. Tabular analysis shows the results of some physical parameters like skin friction coefficient, Nusselt number and Sherwood number due to the variation of Walter's B parameter, thickness parameter and chemical reactive parameter.

A STEADY CASSON FLUID FLOW PAST A STRETCHING POROUS SURFACE IN PRESENCE OF HEAT SOURCE AND CHEMICAL REACTION

In this problem a steady Casson fluid flow past an exponentially stretching porous surface is considered with Suction/blowing. Here a uniform magnetic field is applied in the transverse direction to the flow. The governing partial differential equations are reduced to a set of non-linear ordinary differential equations which are further solved numerically with the help of Matlab Build BVP4C technique. Results are discussed with the help of graphs and tables for various values of flow parameters. A special emphasize is given in the effect of Casson fluid parameter on fluid velocity, heat and mass transfer rate of the system.

Numerical analysis of fractional viscoelastic fluid problem solved by finite difference scheme

The finite difference schemes for equations depicting the fluid flow, heat and mass transfer of viscoelastic fluid in porous media based on fractional constitutive model are analyzed, when Soret and Dufour effects are taken into account. Different from the conventional fractional partial differential equations, the governing momentum equation of this system not only contains convection terms, but also a term: Dtβ0(∂2u/∂y2), which are great challenges when we do the stability analysis. In addition, the temperature equation and concentration equation are coupled with each other, which increases the difficulty of numerical analysis. By using the energy method, the stability and convergence of the finite difference schemes employed for the governing equations are obtained. The accuracy of the scheme for momentum equation is O(τ+hx2+hy2), while the one for temperature and concentration equations is O(τ2+hx2+hy). Finally, numerical examples are presented to verify methods and demonstrate the analysis effectiveness.

Analysis of Ozonation Processes Using Coupled Modeling of Fluid Dynamics, Mass Transfer, and Chemical Reaction Kinetics.

The efficacy of oxidation of recalcitrant organic contaminants in municipal and industrial wastewaters by ozonation is influenced by chemical reaction kinetics and hydrodynamics within a reactor. A 3D computational fluid dynamics (CFD) model incorporating both multiphase flow and reaction kinetics describing ozone decay, hydroxyl radical (•OH) generation, and organic oxidation was developed to simulate the performance of continuous flow ozonation reactors. Formate was selected as the target organic in this study due to its well-understood oxidation pathway. Simulation results revealed that the dissolved ozone concentration in the reactor is controlled by rates of O3(g) interphase transfer and ozone self-decay. Simulations of the effect of various operating conditions showed that the reaction stoichiometric constraints between formate and ozone were reached; however, complete utilization of gas phase ozone was hard to achieve due to the low ozone interphase mass transfer rate. Increasing the O3(g) concentration leads to an increase in the formate removal rate by ∼5% due to an enhancement in the rate of O3(g) interphase mass transfer. The CFD model adequately describes the mass transfer occurring in the two-phase flow system and confirms that O3(g) interphase mass transfer is the rate-limiting step in contaminant degradation. The model can be used to optimize the ozone reactor design for improved contaminant degradation and ozonation efficiency.

Computation of bio-nano-convection power law slip flow from a needle with blowing effects in a porous medium

Transport phenomena with fluid flow, heat, mass, nanoparticle species and microorganism transfer external to a needle in a porous medium have many biomedical engineering applications (e.g. hypodermic needles used in hemotology). It is also used to design many biomedical engineering equipment's and coating flows with bio-inspired nanomaterials. Coating flows featuring combinations of nanoparticles and motile micro-organisms also constitute an important application area. A model for convective flow of a power-law nanofluid containing gyrotactic micro-organisms past a needle in a Darcy porous medium is developed. Multiple slips and Stefan blowing effects at the needle boundary are considered. The model features a reduced form of the conservation of equations with appropriate coupled boundary conditions. The governing equations are converted to similarity equations using appropriate invariant transformations. The transformed equations have been solved numerically using the in-built Matlab bvp4c function. The influence of the emerging parameters on the flow characteristics, friction, heat, mass, and micro-organism transfers are discussed in detail. Note that velocity decreases whilst temperature, concentration, and density of motile micro-organism increase with an increase in blowing parameter for shear thinning, Newtonian, and shear thickening fluids. All physical quantities are decreasing with increasing blowing, Darcy, power law and needle size parameters.

Impact of liquid coolant subcooling on boiling heat transfer and dryout in heat-generating porous media

The present article discusses the impact of liquid coolant subcooling on multiphase fluid flow and boiling heat transfer in porous media with internal heat generation. Although extremely relevant and important, only limited studies are available in the open literature on the effects of coolant subcooling in heat-generating porous media and hence, this requires a detailed analysis. The present analysis is carried out using a validated computational model of multiphase fluid flow through clear fluid and porous media considering the relevant fluid transport, heat transfer and mass transfer phenomena. Results suggest that the qualitative nature of boiling heat transfer from the heat-generating porous body, with subcooled coolants, remain similar to that observed with a saturated coolant. Quantitative differences are, however, observed as a result of solid–liquid convective heat transfer, and competing mechanisms of boiling and condensation heat transfer, when subcooled liquid coolant is present. It is observed that a substantially larger heating power density is required - as coolant subcooling is increased - for achieving the same temperature rise in the porous body. Dryout power density at different coolant subcooling is also observed to follow a similar trend. The thermal energy removal limit is, hence, observed to be substantially enhanced in presence of subcooled coolants. Further, the dryout region within the porous body is observed to gradually shift towards its interior as the coolant subcooling is increased.

Insight into the motion of water conveying three kinds of nanoparticles shapes on a horizontal surface: Significance of thermo-migration and Brownian motion

Thermo-migration and erratic/random motion of tiny particles are some of the attributes of these objects in liquid medium that can affect the performance and transportation of nanofluids. With major emphasis on the fluctuation of friction, heat, and mass transfer rates across the domain, little is known about the dynamics of water colloidally mixed with three distinct types of nano-sized particles. The suitable models, as well as the dimensional governing equation, were non-dimensionalized and parameterized using appropriate similarity variables for analyzing the colloidal mixture of platelet, cylindrical, and spherical nanoparticles. The validity, reliability of the numerical integration and the newly acquired findings were extensively investigated. The results for boundary layer flow show that increasing the density of spherical nanoparticles causes (a) a reduction in the friction between the layers of water-based ternary-hybrid nanofluid and the wall (b) an increment in the friction from the wall till the free stream. Accumulation of species that form water-based ternary-hybrid nanofluid decline due to higher erratic motion and thermo-migration of different nanoparticles. But there is an enhancement in the mass transfer rate near the wall due to erratic motion and thermo-migration of different nanoparticles. The Nusselt number proportionate to heat transfer rate decreases with increased thermo-migration of nanoparticles. With increasing Brownian motion of three distinct nanoparticles, the heat transfer and temperature distribution diminish across the fluid flow but mass transfer is magnified.

Numerical determination of bubble size distribution in Newtonian and non-Newtonian fluid flows based on the complete turbulence spectrum

Gas-liquid mass transfer in non-Newtonian fluids is a crucial aspect of the bioprocess industry. Mass transfer is analyzed using the coefficient kLa, which is limited by the rheology since it exerts a barrier to the fluid deformation, significantly affecting the oxygen diffusivity and the bubble breakup and coalescence. However, the traditional mathematical expressions to model the bubble size distribution from bubble breakup and coalescence in turbulent flows of Newtonian fluids are restricted to the inertial sub-range of turbulence where the kinetic energy is dominated only by the microscales. Application of the Newtonian models to non-Newtonian fluids could result in inaccurate predictions by not considering the continuous phase rheology. The main goal of this research is the numerical determination and experimental comparison of bubble sizes in different axial positions of a bioreactor stirred by a Rushton turbine. Emphasis was placed on the viscosity effects on simulating bubble dispersion in a Newtonian fluid (water) and its comparison with a non-Newtonian fluid (0.4 % CMC). The mathematical framework is constructed by coupling the hydrodynamics (through computational fluid dynamics CFD) and bubble breakup and coalescence from a turbulence perspective using the complete energy spectrum that considers the contributions from the energy containing, inertial, and dissipation sub-ranges. This is achieved by including the second-order structure–function. The results of bubble sizes and kLa were compared with experimental data, and acceptable agreement was achieved. Therefore, it is shown that the viscous effects were captured numerically by the entire energy spectrum and improved the predictions of the kLa and bubble sizes compared to the traditional structure function turbulence models.

Magneto-Soret-Dufour thermo-radiative double-diffusive convection heat and mass transfer of a micropolar fluid in a porous medium with Ohmic dissipation and variable thermal conductivity

This paper deals with developing a numerical boundary layer flow model to analyze convective heat transfer characteristics of a micropolar fluid past a vertical plate in a composite material with viscous-Ohmic dissipations in the presence of a transverse magnetic field. The basic governing equations are solved numerically by using the Runge-Kutta-Fehlberg method. The computed results reveal a reduction in the velocity, temperature, and microrotation profiles by increasing the Prandtl number. Also, the concentration distribution is enhanced by enhancing or decreasing Soret-Dufour parameter, and there seems to be decremented in the skin-friction coefficient values with Schmidt number.

Effect of pore space heterogeneity on the adsorption dynamics in porous media at various convection-diffusion and reaction conditions: A lattice Boltzmann study

This paper investigates the influence of pore space heterogeneity on the adsorption dynamics in a single-phase flow. The sensitivity of adsorption dynamics to changes in heterogeneity, which is numerically described by the disorder parameter, is studied in combination with the Peclet number, porosity, adsorption rate constant, and absolute permeability. The focus is on applied results that are useful, for example, in chemical and petroleum engineering. The main findings of this paper were obtained in mathematical modeling based on lattice Boltzmann equations (LBE) for fluid flow (MRT collision scheme) and mass transfer processes (SRT collision scheme). Mass transfer at the adsorbent/adsorbate interface is described using the kinetics law of Langmuir adsorption. Numerical simulations are performed on digital images of the porous structures generated using Monte-Carlo's movement method, which controls the pore space heterogeneity. In this work, special attention is paid to the choice of the relaxation parameter in LBE for mass transfer, which affects the adsorption dynamics. The results of this paper show that heterogeneity significantly affects the dynamics of the adsorbed amount. An increase in the disorder parameter leads to a decrease in the velocity of the concentration front and a slowdown in the adsorption rate. It was found that the sensitivity of the dynamics of adsorption to a change in heterogeneity is maximum at low Peclet numbers. The impact of the disorder on adsorption significantly decreases with an increase in the Peclet number. With the prevalence of the convection mechanism, the adsorption dynamics is practically unaffected by heterogeneity. The effect of heterogeneity is most pronounced at low porosity and decreases significantly with its growth. At high porosity, the influence of heterogeneity on the adsorption dynamics was not revealed. The Damkohler number affects the sensitivity of the adsorption dynamics to changes in pore space heterogeneity. The effect of heterogeneity increases with the increasing intensity of mass transfer. In addition, it was found that absolute permeability does not affect adsorption.

MHD flow, radiation heat and mass transfer of fractional Burgers' fluid in porous medium with chemical reaction

Non-Newtonian fluids such as asphalt are widely used in engineering field, but their application will also cause environmental pollution. This paper investigates the MHD flow of this kind of non-Newtonian fluid in porous media by using fractional Burgers' model. The effects of first-order chemical reaction, radiation effects and periodic oscillating boundary condition on fluid flow, heat and mass transfer are considered. The governing equations including a multi-term time fractional derivative are obtained by using the modified Darcy's law, fractional Fourier's law and fractional Fick's law. A convergent and stable L-algorithm, is established for governing equations. The influences of model parameters on the velocity, temperature and concentration distributions are analyzed. Numerical simulation results indicate that fractional derivative α and Darcy number Da have significant effect on velocity distribution. The momentum boundary layer becomes thinner remarkably with fractional derivative α. While the influence of Darcy number Da on the velocity performs conversely.

Optimization of Thermo-Physical Properties For The Binary System Of Acetone–Water At 303.15-318.15 K By Response Surface Quadratic Model

Thermo bodily residences of binary liquid combos are very beneficial in biotechnology, pharmaceutical, chemical and petroleum refining industries for improved favoured products from diverse raw materials. The physical property data on mixed solvents are important for the theoretical and applied areas of research and are frequently used in many chemical and industrial processes such as design of new process and process equipment (fluid flow, mass transfer or heat transfer calculation) and designing of bioreactor/fermenter. The objective of the current paper is to determine the density, viscosity, ultrasonic velocity, refractive index and surface tension of acetone (1) + water (2) at temperatures of 303.15K to 318.15K for the complete composition degrees and atmospheric pressure. These experimental values were used to calculate the respective excess homes in conjunction with a few acoustic properties. The experimental facts and excess residences have been used to calculate the interacting coefficients and well known deviations from different existing models. Also the new model equations have been evolved with the aid of the use of Design Expert application for density, viscosity, ultrasonic velocity, refractive indices and surface tension. Experimental consequences have been analysed on the premise of molecular interactions among element molecules with the assistance of FT-IR spectrum. Acetone-water binary structures of the prevailing observer have positive values of excess molar volumes and deviations in isentropic compressibility over whole composition range and at all temperatures which suggests sturdy interactions among the components of binary mixtures. Thermodynamic observations of acetone and water mixtures were made. Negative viscosity deviation of acetone-water combinations suggests robust dipole-dipole interactions within the device. Fourier remodel infrared spectroscopy also indicates the sturdy interaction made at 3589 cm-1 and based on the response surface method outcomes, more interplay takes area at zero. Five and zero six moles of acetone and water combination and the consequences are conformed with reference to the R2 cost (0.89). Excess molar extent and isentropic compressibility were decided and kinds of interactions have been discussed primarily based on the derived properties.

Blasius-Rayleigh-Stokes Flow of Hybrid Nanomaterial Liquid Past a Stretching Surface with Generalized Fourier's and Fick's Law.

The effect of Stefan blowing on the Cattaneo–Christov characteristics of the Blasius–Rayleigh–Stokes flow of self-motive Ag-MgO/water hybrid nanofluids, with convective boundary conditions and a microorganism density, are examined in this study. Further, the impact of the transitive magnetic field, ablation/accretion, melting heat, and viscous dissipation effects are also discussed. By performing appropriate transformations, the mathematical models are turned into a couple of self-similarity equations. The bvp4c approach is used to solve the modified similarity equations numerically. The fluid flow, microorganism density, energy, and mass transfer features are investigated for dissimilar values of different variables including magnetic parameter, volume fraction parameter, Stefan blowing parameter, thermal and concentration Biot number, Eckert number, thermal and concentration relaxation parameter, bio-convection Lewis parameter, and Peclet number, to obtain a better understanding of the problem. The liquid velocity is improved for higher values of the volume fraction parameter and magnetic characteristic, due to the retardation effect. Further, a higher value of the Stefan blowing parameter improves the liquid momentum and velocity boundary layer thickness.

Application of Legendre polynomials based neural networks for the analysis of heat and mass transfer of a non-Newtonian fluid in a porous channel

In this paper, the mathematical models for flow and heat-transfer analysis of a non-Newtonian fluid with axisymmetric channels and porous walls are analyzed. The governing equations of the problem are derived by using the basic concepts of continuity and momentum equations. Furthermore, artificial intelligence-based feedforward neural networks (ANNs) are utilized with hybridization of a generalized normal-distribution optimization (GNDO) algorithm and sequential quadratic programming (SQP) to study the heat-transfer equations and calculate the approximate solutions for the momentum of a non-Newtonian fluid. Legendre polynomials based Legendre neural networks (LNN) are used to develop a mathematical model for the governing equations, which are further exploited by the global search ability of GNDO and SQP for rapid localization convergence. The proposed technique is applied to study the effect of variations in Reynolds number Re on the velocity profile (f^{prime }) and the temperature profile (q). The results obtained by the LeNN-GNDO-SQP algorithm are compared with the differential transformation method (DTM), which shows the stability of the results and the correctness of the technique. Extensive graphical and statistical analyses are conducted in terms of minimum, mean, and standard deviation based on fitness value, absolute errors, mean absolute deviation (MAD), error in the Nash–Sutcliffe efficiency (NSE), and root mean square error (RMSE).

Математическое моделирование течения многофазного потока в однопоровом коллекторе

The flowing process of multiphase flows in single-pore reservoirs is considered. The multiphase flow in the well is formed by mixing oil, formation water and petroleum gas. A mathematical model is presented that describes the process of mass transfer of a two-phase fluid in a single-pore reservoir during a hydrodynamic study on a well. Based on the model, a difference scheme is constructed. The scalar sweep method is used as a method for solving a system of linear algebraic equations. The analysis of the influence of various characteristics of productive formations, reflecting their influence on the pressure dynamics, was carried out. The optimal time for conducting a hydrodynamic study on a production well was calculated. Modeling was carried out in the developed compact software.

Numerical Solution of Casson Fluid Flow under Viscous Dissipation and Radiation Phenomenon

This article numerically investigates the 2D, steady, laminar, incompressible fluid flow, mass and heat transfer of a non-Newtonian fluid model induced by stretching surface. A Casson fluid model is considered to study the non-Newtonian behavior of the flowing fluid. The magnetic field and a porous medium are considered in the flow momentum, whereas the viscous dissipation is also taken into account in the energy transport phenomena. To see the fluid concentration, the concentration equation is used. Furthermore, the Nusselt number coefficient and skin friction are modified with the addition of nonlinear stretching and radiation parameters. With the similarity transformation, the nonlinear governing partial differential equations are transformed into a system of ordinary differential equations and then numerically solved using a fourth-order Runge-Kutta scheme with the shooting method. The relevant parameters of interest are interpreted for graphical results. The results illustrate that the fluid energy increases effectively with an increase in the Eckert number, radiation parameter, and heat source parameter, while it decreases by increasing the Prandtl number and heat sink parameter. Both the wall skin friction and the wall Nusselt number coefficient decelerate with an increase in the Casson parameter.

Fluid Dynamics and Mass Transfer in Curved Reactors: A Cfd Study on Dean Flow Effects for Nox Degradation

Fluid Dynamics and Mass Transfer in Curved Reactors: A Cfd Study on Dean Flow Effects for Nox Degradation

Numerical modeling of multiphase mass transfer processes in fractured-porous reservoirs

The paper presents an algorithm for solving the problem of the process of mass transfer of a two-phase fluid in a fractured-porous reservoir in a one-dimensional formulation. The presence of natural fractures in such reservoirs impedes various types of exploration and field development. Fractured-porous reservoirs are characterized by intense exchange fluid flow between fractures and porous blocks. Each system has its own individual set of filtration-capacity parameters, and this fact complicates the problem under consideration. To study the mass transfer of a two-phase fluid in a medium with double porosity, a four-block mathematical model with splitting by physical processes is proposed. The model is described by a system of partial differential equations. The splitting method forms two functional blocks on the water saturation and the piezoconductivity. For the numerical solution of this system, an absolutely stable implicit finite-difference scheme is constructed in the one-dimensional case. On the basis of the proposed difference scheme, pressures and saturations in the fracture system and matrix are obtained.

Comparative study of heat and mass transfer of generalized MHD Oldroyd-B bio-nano fluid in a permeable medium with ramped conditions

This article aims to investigate the heat and mass transfer of MHD Oldroyd-B fluid with ramped conditions. The Oldroyd-B fluid is taken as a base fluid (Blood) with a suspension of gold nano-particles, to make the solution of non-Newtonian bio-magnetic nanofluid. The surface medium is taken porous. The well-known equation of Oldroyd-B nano-fluid of integer order derivative has been generalized to a non-integer order derivative. Three different types of definitions of fractional differential operators, like Caputo, Caputo-Fabrizio, Atangana-Baleanu (will be called later as C,CF,AB) are used to develop the resulting fractional nano-fluid model. The solution for temperature, concentration, and velocity profiles is obtained via Laplace transform and for inverse two different numerical algorithms like Zakian’s, Stehfest’s are utilized. The solutions are also shown in tabular form. To see the physical meaning of various parameters like thermal Grashof number, Radiation factor, mass Grashof number, Schmidt number, Prandtl number etc. are explained graphically and theoretically. The velocity and temperature of nanofluid decrease with increasing the value of gold nanoparticles, while increase with increasing the value of both thermal Grashof number and mass Grashof number. The Prandtl number shows opposite behavior for both temperature and velocity field. It will decelerate both the profile. Also, a comparative analysis is also presented between ours and the existing findings.

Entropy Generation Analysis of Radiated Magnetohydrodynamic Flow of Carbon Nanotubes Nanofluids with Variable Conductivity and Diffusivity Subjected to Chemical Reaction

The purpose of this article is to analyze the entropy generation and heat and mass transfer of carbon nano-tubes (CNTs) nanofluid by considering the applied magnetic field under the influence of thermal radiation, variable thermal conductivity, variable mass diffusivity, and binary chemical reaction with activation energy over a linearly stretching cylinder. Convective boundary conditions on heat and mass transfer are considered. An isothermal model of homogeneous-heterogeneous reactions is used to regulate the solute concentration profile. It is assumed that the water-based nanofluid is composed of single and multi-walled carbon nanotubes. Employing a suitable set of similarity transformations, the system of partial differential equations is transformed into the system of nonlinear ordinary differential equations before being solved numerically. Through the implementation of the second law of thermodynamics, the total entropy generation is calculated. In addition, entropy generation for fluid friction, mass transfer, and heat transfer is discussed. This study is specially investigated for the impact of the chemical reaction, and activation energy with entropy generation subject to distinct flow parameters. It is found that the slip parameters greatly influence the flow characteristics. Fluid temperature is elevated with higher radiation parameters and thermal Biot number. Entropy and Bejan number are found to be an increasing function of solid volume fraction, magnetic field, and curvature parameters. Binary chemical reaction and activation energy on concentration profile have opposite effects.