Riga Surface Research Articles

Non‐Newtonian electromagnetic fluid flow through a slanted parabolic started Riga surface with ramped energy

AbstractThe present study deals with the implications of non‐Newtonian fluid via a slanted parabolic started surface with ramped energy. In addition, the characteristics of electrically conducting viscoelastic liquid moving across the Riga surface are investigated systematically, emphasized within the time‐dependent concentration and temperature variations. The mathematical model is made possible by enforcing momentum and heat conservation principles in the format of partial differential equations (PDEs). Heat considerations are emphasized with respect to radiant heat influx. Similarity characteristics are leveraged to convert PDEs to ordinary differential equations. The Laplace transform method is used to find the exact solutions for the obtained differential configuration. The effect of flow on associated patterns is depicted graphically and with tables. Furthermore, fluctuation in relevant engineering parameters such as wall shear stress, temperature, and mass variability on the surface is measured. The range of parameters selected is as follows: , , , , , and . The analytical and numerical solutions are validated and in good agreement. It is worth reporting that the improved Hartmann number and thermal radiation values boost velocity dispersion and skin friction. As expected, respectively, energy and mass transfer rates are escalated with large values of Prandtl number and Schmidt number.

Numerical solution of gyrotactic microorganism flow of nanofluid over a Riga plate with the characteristic of chemical reaction and convective condition

Bioconvection is a familiar phenomenon of fluid mechanics which explains the hydrodynamic unsteadiness and suspensions of upward swimming microorganisms. Hydrodynamic unsteadiness is due to coupling in physical properties such as fluid flows and the density of microorganisms. The article simulates the nanoflow of Powell-Eyring fluid through the Riga surface. Numerical code of Range-Kutta method incorporated with shooting technique is generated on Matlab to track the Brownian motion of microorganisms. The contribution of the chemical reaction is also taken into account for expediting thermophoretic force in magnetohydrodynamic (MHD) nanoflow. Parametric study reveals that shear stress at the walls of the Riga surface and motion of the microorganisms are significantly influenced by the magnetic parameter and other dimensionless quantities.

Thermophoretic movement, heat source, and sink influence on the Williamson fluid past a Riga surface with positive and negative Soret‐Dufour mechanism

AbstractThis study investigates the boundary layer motion of Williamson fluid over an electromagnetic with thermophoretic movement, variable thermal conductivity and viscosity, nonlinear radiation, and Soret‐Dufour influences. The real prediction of regional movement and temperature‐dependent properties of the non‐Newtonian fluids in real space (three‐dimensional [3D]) becomes imperative due to their numerous industrial, engineering, and biomedical use. This flow motion is induced as a result of the introduced mechanism (Riga plate) capable of controlling a weakly hydromagnetic flow. To actualize the aim of this study, the formulated governing partial differential equations conveying the flow model of Williamson fluid in a 3D sense are transformed to systems of ordinary differential equations (ODEs) via applicable similarity variables. The reduced systems of ODEs are solved numerically by the collocation approach. Therein, the Riga surface is seen preventing the heat source/sink impact on the flow fields, the thermophoretic impact indicates a more accumulation of Williamson fluid particles in the cold region thus resulting in higher fluid concentration. Thermal variability energizes the energy field positively, momentum boundary layer reduction prevails for higher Williamson number while heat source dominates the temperature field and heat sink showcases its ability to enhance the fluid concentration in contrast to the heat source.

Heat and mass transfer exploration of non-Newtonian fluid flow induced by the exponentially stretching Riga surface with the application of Generalized Fourier’s and Fick’s law

In the present article, the analysis of the transportation of thermal and solutal energy of a3D flow on second- grade fluid with porous medium by an exponentially stretching surface is presented. The chemical reaction and heat generation/absorption are considered the dominating agents for the transportation of mass and heat in the second-order fluid. Furthermore, slip boundary conditions are considered on the boundary of the surface. A novel concept of the Cattaneo-Christov heat flux theory of the flow of second-order fluid is used under the effects of the Joule heating across the Riga surface for this research examination. The prevailing nonlinear PDEs are changed into the nonlinear coupled ordinary differential equations by choosing the suitable similarity transformations. The Matlab approach Bvp4c is applied to solve the nonlinear ODEs. Physical consequences of the different emerging parameters on the thermal, concentration, and momentum boundary layer thickness are examined by graphs. The thermal and concentration profiles are decreased by enhancing the values of (thermal relaxation parameter of time) and the (parameter of solutal relaxation time), respectively.

Numerical framework for unsteady bioconvection flow of third-grade nanofluid over a porous Riga surface with convective Nield approach

The ultra-high significances of thermal radiation, magnetic field and activation energy in thermal enhancement processes allow significant applications in chemical and mechanical engineering, modern technology and various thermal engineering eras. The improvement in energy resources and production became one of the major challenges for researchers and scientists for sustained development in industrial growths. Beside this, the bioconvection assessment in nanomaterials conveys prestigious applications in biotechnology like bio-sensors, enzymes, petroleum industry, bio-fuels and many more. In view of such renewable applications, present exploration discloses unsteady two-dimensional flow of third-grade nanomaterial accommodating gyrotactic microorganisms induced by unsteady stretched Riga sheet in porous medium. The formulated flow problem is further scrutinized by utilizing the chemical reaction, activation energy, thermal radiation and magnetic aspects. The convective Nield constraints are further subjected in the current investigation. Apposite transformations are used to condense the nonlinear developed problem into dimensionless ordinary form. The numerical solution of such similar flow problem is presented via shooting technique. The detailed graphical illustrations of the dimensionless temperature, nanoparticles concentration, velocity and motile microorganisms for physical significance of diverse relevant parameters are deliberated. Furthermore, numerical data of local Sherwood, Nusselt and motile density numbers is designated in tabular form. Study accentuated that velocity increases for higher modified Hartmann and material constants, while the effects of buoyancy ratio and bioconvected Rayleigh numbers are rather opposite. The temperature, microorganism and concentration distributions were enhanced for unsteady parameter. It is also acknowledged that the concentration distribution is enhanced for activating the energy number. Moreover, the microorganism distribution enhances for concentration difference and magneto-porous constants, while bioconvected Lewis and Peclet numbers show conflicting trend.

NONSIMILAR FORCED CONVECTION ANALYSIS OF CHEMICALLY REACTIVE MAGNETIZED EYRING-POWELL NANOFLUID FLOW IN A POROUS MEDIUM OVER A STRETCHED RIGA SURFACE

Flows across porous medium have vital roles due to their implementations in the fields of biology and environmental systems. The objective of the current article is to investigate the forced convection of magnetized Eyring-Powell nanofluid flow in a porous medium above a Riga surface through nonsimilar modeling. The current model assumes viscous dissipation, activation energy, chemical reaction, heat generation, and convective boundary conditions. The Riga plate is presented as an electromagnetic actuator based on permanent magnets and recurring conducts of electrodes placed on the plane of the sheet. In nonsimilar flows, the basic quantities vary in the flow direction. The system describing Eyring-Powell models are transmuted into dimensionless nonsimilar form by the utilization of nonsimilar transformations. The nonsimilar system is analytically simulated by employing local nonsimilarity (LNS) up to the second order of iteration and numerically via bvp4c. It is explored that the temperature field represents an escalating manner for distinct variations of Eckert number and radiation parameter. The modified Hartman number and Eckert number enhances both velocity and temperature. The Eckert number expands the concentration portrayal of nanoparticles. Furthermore, the thermophoresis and Brownian factors of nanofluid with activation energy are investigated. The shear stress of the wall expands for the values of the Eyring-Powell parameter and modified Hartmann number. The values of flow, heat, and mass transfer rate for distinct parameters are also illustrated in tables. In limited cases, excellent agreement is found between the present work and published articles.

Thermophoretic particle deposition and heat generation analysis of Newtonian nanofluid flow through magnetized Riga plate

AbstractThe Riga surface is composed of an electromagnetic actuator that comprises a span‐wise associated array of discontinuous electrodes and an everlasting magnet mounted over a planer surface. The electro‐magneto‐hydrodynamic has an attractive role in thermal reactors, fluidics network flow, liquid chromatography, and micro coolers. Inspired by these applications, a laminar, two‐dimensional nanofluid flow with uniform heat sink‐source, thermophoretic depositions of the particles, and the Newtonian heating effect are investigated. The equations that describe the fluid motion are reduced into a system of ordinary differential equations with the help of spatial similarity variables. Numeric solutions of ordinary differential equations are executed through the Runge–Kutta–Felhberg 45 order technique via a shooting scheme. The role of various nondimensional factors on physically interesting quantities is elaborated graphically. The velocity profile rises for modified Hartmann number and decreases for porosity parameter. Thermal enhancement is high in the common wall temperature condition comparative to the case of the Newtonian heating conditions. The concentration profile is enhanced with Schmidt number, but the reverse trend is observed for the thermophoretic parameter. The rate of mass transfer is increased with Schmidt number.

Analysis of entropy generation and Joule heating on curvilinear flow of thermally radiative viscous fluid due to an oscillation of curved Riga surface

This paper investigates the phenomena of heat transfer and entropy generation on time-dependent electro-magnetohydrodynamic boundary layer flow of viscous fluid past a curved oscillatory stretchable Riga surface. Also, the impacts of thermal radiation and Joule heating are accounted for in the energy equation. To develop the flow model in mathematical form, curvilinear coordinates system is followed. The series solution of the governing nonlinear partial differential equations is attained with the help of the homotopy analysis method (HAM). The impacts of various involved parameters like dimensionless radius of curvature, modified magnetic parameter, the proportion of frequency of oscillation of the sheet to its stretchable rate parameter, magnetic parameter, Prandtl number, Eckert number, radiation parameter and Brinkman number on entropy generation, Bejan number, temperature and flow equations are comprehensively examined and results are displayed through graphs. Numerical variation in the magnitude of surface drag force and local Nusselt number under the influence of aforesaid parameters are presented through the tables. Entropy generation is enhanced with an enhancement in a radius of curvature and Brinkman number, while the Bejan number shows opposite behavior for both parameters. The amplitude of velocity distribution shows growing behavior with modified magnetic parameter.

Analytical simulation of time dependent electromagneto-hydrodynamic flow of Williamson fluid due to oscillatory curved convectively heated Riga surface with variable thermal conductivity and diffusivity

The main objective of the present article is to provide an analytical simulation for time dependent boundary layer flow of non-Newtonian Williamson fluid due to stretchable curved oscillatory Riga surface. Also the characteristics of heat and mass transport are studied under the influence of variable thermal conductivity and diffusivity along with convective heat and mass boundary conditions. Additionally, energy equation is also characterized with the impact of heat production. Curvilinear coordinate scheme is followed to attain the boundary layer expressions for the flow model. The governing nonlinear partial differential equations are solved analytically via homotopy analysis method (HAM). Graphs are plotted to examine comprehensively the consequences of various concerned parameters like modified magnetic parameter and radius of curvature, Williamson fluid parameter, relation of the surface's oscillating frequency to its stretching rate constant, Prandtl number, variable conductivity and heat production parameters, Schmidt number and variable diffusivity parameter on concentration, temperature, pressure and velocity profile. Also the outcomes of afore said variables on surface drag force, rate of temperature and mass transmission (Nusselt and Sherwood numbers) are shown in tabular form. The liquid velocity amplitude is enhanced with modified magnetic parameter and shows opposite behavior for Williamson fluid parameter.

Melting heat transportation in chemical reactive flow of third grade nanofluid with irreversibility analysis

Melting effect in flow of third grade nanomaterials by a Riga surface is examined. Flow is created due to stretched surface. Thermal transportation characteristics are developed through heat source/sink and thermal radiation. Furthermore thermophoresis and random diffusion performances are also deliberated. Irreversibility analysis is addressed through thermodynamics second law. Second law thermodynamics allow us to recognize how well an isolated closed system performs in terms of the quality of the energy. Isothermal cubic autocatalysis chemical reactions are scrutinized at catalytic surface. Adequate transformations are employed to develop nonlinear set of ordinary differential system. Optimal homotopy analysis technique (OHAM) is utilized to construct convergent solution. Influences of several sundry variables for velocity field, temperature distribution, entropy optimization and concentration distribution are graphically examined. An opposite scenario is observed for temperature and velocity through melting parameter. Concentration and temperature have reverse trends against thermophoresis variable. A similar scenario is seen for entropy generation against radiation and melting parameters.

Flow of nanofluid towards a Riga surface with heat and mass transfer under the effects of activation energy and thermal radiation

This paper numerically simulates the nanofluid flow over a thermally expanding Riga plate. Buongiorno model for nanofluid is employed to investigate the contribution of Brownian motion and thermophoretic force on the nanoflow. Magnetohydrodynamics (MHD) of viscous nanofluid through a porous medium is characterized with the help of Darcy–Forchheimer’s model. In addition, the simultaneous effects of activation energy and chemical reaction have been incorporated. Moreover, highly nonlinear coupled differential equations are formulated which highlight the influence of viscous dissipation and heat generation. A numerical solution is achieved with the help of the Range–Kutta fourth-order (RK4) method combined with the shooting technique. Finally, the role of emerging parameters is studied via performing the numerical simulation which reveals that the momentum boundary layer of nanofluid shrinks due to the porous medium. Whereas, thermal boundary layer expands for all variables, except for the Prandtl number. Finally, mass transfer rated suffers due to Schmidt number.

Zero and Nonzero Mass Flux Effects of Bioconvective Viscoelastic Nanofluid over a 3D Riga Surface with the Swimming of Gyrotactic Microorganisms

This work addresses 3D bioconvective viscoelastic nanofluid flow across a heated Riga surface with nonlinear radiation, swimming microorganisms, and nanoparticles. The nanoparticles are tested with zero (passive) and nonzero (active) mass flux states along with the effect of thermophoresis and Brownian motion. The physical system is visualized via high linearity PDE systems and nondimensionalized to high linearity ordinary differential systems. The converted ordinary differential systems are solved with the aid of the homotopy analytic method (HAM). Several valuable and appropriate characteristics of related profiles are presented graphically and discussed in detail. Results of interest such as the modified Hartmann number, mixed convection parameter, bioconvection Rayleigh number, and Brownian motion parameter are discussed in terms of various profiles. The numerical coding is validated with earlier reports, and excellent agreement is observed. The microorganisms are utilized to improve the thermal conductivity of nanofluid, and this mechanism has more utilization in the oil refinery process.

Marangoni Convective Flow of GO-kerosene- and GO-water-based Casson Nanoliquid Toward a Penetrable Riga Surface

Marangoni Convective Flow of GO-kerosene- and GO-water-based Casson Nanoliquid Toward a Penetrable Riga Surface

Buoyancy Effect on a Micropolar Fluid Flow Past a Vertical Riga Surface Comprising Water-Based SWCNT–MWCNT Hybrid Nanofluid Subject to Partially Slipped and Thermal Stratification: Cattaneo–Christov Model

This paper provides a comprehensive analysis of the mixed convective flow that comprises SWCNT-MWCNT/water hybrid nanofluid containing micropolar fluid through a partially slipped vertical Riga surface. A Cattaneo–Christov heat flux model is used to examine the heat transport rate. The energy equation is gaining more significance with the effect of viscous dissipation and thermal stratification. The flow model is transformed by convenient transformation into nondimensionless form. The numerical results of nonlinear complex equations are collected using the bvp4c built-in function from MATLAB which is based on the finite difference method. The graphical results are obtained for both hybrid nanofluid and simple nanofluid. The temperature distribution for hybrid nanofluid is higher than that for simple nanofluid when the solid volume fraction increases. The axial friction factor increases with solid volume fraction, porosity parameter, and mixed convection parameter. The velocity graph varies inversely with nanofluid volume fraction and micropolar parameter.

Mathematical Analysis of Thermal Energy Distribution in a Hybridized Mixed Convective Flow

The mixed convective flow of hybrid nanofluid (SWCNT-MWCNT/EG) containing micropolar fluid past a Riga surface embedded in porous medium is explored in detail throughout this study. In the momentum equation, the Darcy Forchheimer effect is used. The heat transfer phenomenon is exploited with viscous dissipation and thermal stratification over a non-Fourier heat flux model. PDEs are transformed into the necessary governing equations using transformations. The numerical results of non-linear governing equations are collected using Matlab function bvp4c. Graphical representations of the effects of relevant parameters on velocity, skin friction, and temperature are shown. The comparison of simple nanofluid and hybrid nanofluid is discussed in graphs. The temperature field is higher for hybrid nanofluid than simple nanofluid when solid volume fraction enhances. With increasing solid volume fraction, porosity parameter, and mixed convection parameter, the axial friction factor rises. The momentum boundary layer is inversely proportional to the slip parameter, Hartman number, variable viscosity and the porosity parameter.

Assisting and Opposing Stagnation Point Pseudoplastic Nano Liquid Flow towards a Flexible Riga Sheet: A Computational Approach

Nanofluids are used as coolants in heat transport devices like heat exchangers, radiators, and electronic cooling systems (like a flat plate) because of their improved thermal properties. The preeminent perspective of this study is to highlight the influence of combined convection on heat transfer and pseudoplastic non-Newtonian nanofluid flow towards an extendable Riga surface. Buongiorno model is incorporated in the present study to tackle a diverse range of Reynolds numbers and to analyze the behavior of the pseudoplastic nanofluid flow. Nanofluid features are scrutinized through Brownian motion and thermophoresis diffusion. By the use of the boundary layer principle, the compact form of flow equations is transformed into component forms. The modeled system is numerically simulated. The effects of various physical parameters on skin friction, mass transfer, and thermal energy are numerically computed. Fluctuations of velocity increased when modified Hartmann number and mixed convection parameter are boosted, where it collapses for Weissenberg number and width parameter. It can be revealed that the temperature curve gets down if modified Hartmann number, mixed convection, and buoyancy ratio parameters upgrade. Concentration patterns diminish when there is an incline in width parameter and Lewis number; on the other hand, it went upward for Brownian motion parameter, modified Hartmann, and Prandtl number.

Enhanced heat transfer in H2O inspired by Al2O3 and γAl2O3 nanomaterials and effective nanofluid models

Currently, thermal improvement in the nanofluids over a curved Riga sheet is a topic of interest and attained popularity among the researchers. Therefore, the colloidal suspension of water suspended by [Formula: see text] and [Formula: see text] over a curved Riga surface is modeled for the heat transfer analysis. The nondimensionalization of the model is accomplished via invertible variables. On the basis of dynamic viscosities and thermal conductivities of [Formula: see text] and [Formula: see text] nanoparticles, two nanofluid models developed over a semi-infinite region. Then, the models solved numerically and found graphical results for the flow characteristics, thermophysical properties and local thermal performance rate by altering the pertinent flow parameters. It is examined that the fluid motion rapidly decreases for [Formula: see text] and momentum boundary layer region decreases. The squeezed and curvature parameters lead to reduce in the nanofluid velocity. The temperature of more magnetized enhances significantly. Thermophysical characteristics of the nanofluids enhance for higher volumetric fraction factor. More heat transfer at the Riga surface for higher M and R.

A study of dual stratification on stagnation point Walters' B nanofluid flow via radiative Riga plate: a statistical approach

Features of double stratification on stagnation point flow of Walter's B nanoliquid driven through Riga surface are examined in the current study. Via solutal stratification, radiation and thermal effects, heat and mass phenomena are evaluated. The novelty of the proposed investigation is focused on the important effect of melting phenomenon and EMHD Lorentz force along with stratification and heat generation over the rheology of the liquid flow. The influence of Brownian and thermophoresis particle deposition is included in transport equations involved in the analysis. Transformation is incorporated by the basic laws of mass, energy and linear momentum to acquire nonlinear differential system of equations. Utilizing Optimal Homotopy Analysis Method through BVPh2.0.0, optimum value of convergence control factors is estimated. Graphical findings for the dimensionless temperature, velocity and concentration for different pertinent parameters are explained. Numerical values of physical interest like skin friction coefficient, local Sherwood number and local Nusselt number are computed and visualized graphically. The heat generation and advanced modified Hartmann number improve the speed of flow. It is also observed that weaker thermal stratification upraises the rate of heat transport, and mass transport rate lessens for stronger mass stratification. In addition, contour graphs of velocity for ratio parameter A describe the accurate perception of flow. The intensity of temperature and concentration field is low owing to double stratification, whereas the stronger radiation corresponds the significantly rise in temperature. Reliability of outcomes assured by means of probable error analysis.

Analytical treatment of radiative Casson fluid over an isothermal inclined Riga surface with aspects of chemically reactive species

This article concerns an examination of thermal attributes generated in non-linearly varying viscosity-dependent viscoelastic fluid flowing over an isothermally inclined riga surface. The mathematical formulation is conceded by obliging conservation laws of momentum and energy in the form of PDE’s. Thermal aspects are highlighted in the attendance of radiative heat flux. Similarity variables are capitalized for the transmutation of PDE’s into ODE’s.Analytical solution of attained differential setup is attained by employing Laplace transform technique. The influence of flow concerning variables on related distributions is divulged in a graphical manner. The variation in quantities of engineering interest like wall shear stress, thermal and mass variation on the surface is also measured.It is found thatthe accelerating parameter, chemical reaction parameter, positive modifiedHartmannnumber, and radiation values improve skin friction while heat absorption parameter retards friction. Moreover, an increment in chemical reaction and heat absorption parameters causes a reduction in momentum distribution.

Numerical and scale analysis of non-Newtonian fluid (Eyring-Powell) through pseudo-spectral collocation method (PSCM) towards a magnetized stretchable Riga surface

A numerical simulation of a two-dimensional Eyring-Powell nanofluid flow is carried out through a Riga plate with radiative walls. Simultaneous contributions of chemical reaction and activation energy have also been taken into account on the mixed convection flow. Lubrication effects are applied by considering second order slip boundary condition in order to reduce the role of skin friction. A set of highly nonlinear and coupled differential equations are tackled with the help of “Pseudo-spectral collocation method” by developing numerical code on MATLAB. A detailed parametric study is performed that reveals that more energy adds to the system in response to slip parameter and Brownian motion of the nano-particles. Numerical results have also been compiled and tabulated. This is worth noticing that skin friction coefficient reduces due to modified Hartmann factor while heat flux is an increasing function of Prandtl number. However, there is a prominent increase in mass flux against all parameter, except activation energy.