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1.
The Buongiorno model Maxwell nanofluid flow, heat and mass transfer characteristics over a stretching sheet with a magnetic field, thermal radiation, and chemical reaction is numerically investigated in this analysis. This model incorporates the effects of Brownian motion and thermophoresis. The governing partial differential equations are transformed into a coupled nonlinear ordinary differential equation by using the similarity transformation technique. The resultant nonlinear differential equations are solved by using the Finite element method. The sketches of velocity, temperature and concentration with diverse values of magnetic field parameter (0.1 ≤ M ≤ 1.5), Deborah number (0.0 ≤ β ≤ 0.19), radiation parameter (0.1 ≤ R ≤ 0.7), Prandtl number (0.5 ≤ Pr ≤ 0.8), Brownian motion parameter (0.1 ≤ Nb ≤ 0.7), thermophoretic parameter (0.2 ≤ Nt ≤ 0.8), Chemical reaction parameter (1.0 ≤ Cr ≤ 2.5) and Lewis number (1.5 ≤ Le ≤ 3.0) have investigated and are depicted through plots. Moreover, the values of the Skin-friction coefficient, Nusselt number, and Sherwood numbers are also computed and are shown in tables. The sequels of this analysis reviewed that the values of Skin-friction coefficient and Sherwood number intensified with hiked values of Deborah number (β), whereas, the values of Nusselt number decelerate as values of (β) improves. 相似文献
2.
The heat transfer mechanism of nanofluids has numerous industrial applications owing to the non-Newtonian behavior and has been exercised as a thermophysical phenomena in presence of thermal radiation. The present paper deals with the thermal transfer characteristics of time-independent magnetohydrodynamics Williamson fluid past a stretching surface in presence of the reaction of chemical equilibrium is dealt. The flow constitutive nonlinear partial differential coupled equations are transmitted into ordinary differential equalities by employing relevant similarity transmutations. These deduced equations are determined by using the Runge–Kutta numerical technique with a shooting approach with the aid of MATLAB software. Influences of distinct pertinent flow parameters like an inclined uniform magnetic field, Soret number, heat generation/absorption, and Schmidt number constrained to convective boundary condition is displayed through graphs with relevant physical interpretations. Computed numerical values for the friction factor coefficient, local Nusselt parameter, and Sherwood number are tabulated. 相似文献
3.
A linear stability analysis is performed for the onset of natural convection in a horizontal nanofluid layer heated from below. The motion of nanoparticles is characterized by both the thermophoresis and Brownian diffusion effects. Different from previous studies in the literature, both the dependences of thermophoresis on nanoparticle volume fraction and Brownian motion on temperature are taken into consideration in the theoretical model. The result reveals that the base flow is mainly dominated by the effect of thermophoresis and the Brownian diffusion coefficient can be treated as a constant reasonably when a finite temperature difference is imposed across the nanofluid layer. Accordingly, a novel base solution of nanoparticle volume fraction is derived. It is found that the profile of nanoparticle concentration depends heavily on the magnitude of thermophoretic diffusion, which may exhibit a nonlinear distribution across the nanofluid layer once the effect of thermophoresis is significant. The suspended nanoparticles produce a strong destabilizing effect and a tiny volume fraction of nanoparticles is sufficient to trigger the onset of convection and make the nanofluid layer become unconditionally unstable. The dispersion spectra of unstable modes are demonstrated and the most unstable mode with the maximum growth rate is explored. The growth rate of the most unstable mode is found to increase significantly with increasing nanoparticle concentration, while the influence of heat capacity ratio of nanoparticle to base fluid on the behavior of thermal convection is negligible. 相似文献
4.
Studies related to enhancing heat transfer has attained much attention of researchers to avail optimized heat‐transfer devices. High viscous fluids are of great importance as they are widely used in petroleum products, organic chemistry, coating, printing, and so forth. In this study, heat transfer mechanism driven by Eyring‐Powell nanoliquid flow in a vertical microchannel is examined. Impact of considering buoyancy force, magnetic field, and convective boundary on the thermal system is demonstrated. The modeled nondimensional equations are computed by using the Runge‐Kutta‐Fehlberg method. The vital roles of thermophoresis and Brownian motion are discussed in detail. The significance of second law analysis for thermal systems is presented. The causes of irreversibilities in a microchannel due to Eyring‐Powell nanoliquid flow is also demonstrated in the current research study. The upshots of the current investigations are visualized through graphical elucidation. It is established that minimization of entropy generation can be achieved by enhancing the mechanism of thermophoresis. The convective boundary helps in transmitting heat from the thermal system to the ambience hence the lower thermal field is attained. 相似文献
5.
An analysis of heat and mass transfer is carried out under the influence of chemical reaction, friction heating, and heat generation/absorption over a curved surface. The impacts of random motion attributes of nanoparticles and thermophoresis are also applied in the expressions of energy and concentration. With the help of assigned transformations, the nonlinear partial differential equations are changed to dimensionless nonlinear ordinary differential equations. Then, the numerical solution is obtained using fourth‐fifth order Runge‐Kutta‐Fehlberg method via the shooting technique. The impacts of relevant parameters on velocity, temperature, and concentration are depicted through graphs and tables. The results illustrate that the lowest concentration distribution of nanofluid is related to the higher value of chemical reaction parameter. Moreover, it is found that thermophoresis and Brownian motion parameters have a propensity to increase the temperature profile while curvature parameter decreases the velocity profile. Also, velocity and temperature fields show a similar behavior for the increasing values of volume fraction of the nanoparticles, while a reverse trend is observed in the concentration profile under the same condition. To authenticate the results of the current study, the obtained data were compared with previously published data. 相似文献
6.
The convection in a vertical channel filled with a porous medium saturated by a nanofluid is studied numerically. The effects of Brownian motion and thermophoresis are incorporated in the model used for nanofluid. Also, the flow within the porous region is governed by Brinkman's equation. The generalized eigenvalue problem for the perturbed state is obtained from a normal mode analysis and solved using the Chebyshev spectral collocation method. The Rayleigh number is expressed as an implicit function of the wavenumber with other parameters. The critical wavenumber and the critical Rayleigh number are calculated for different parameters. The preferred modes under critical conditions are detected. 相似文献
7.
This analysis explores the influence of magnetohydrodynamic (MHD) nanofluid flow over a stretching cylinder with radiation effect in presence of chemically reactive species. The thermal radiation phenomenon is incorporated in the temperature equation. The mathematical modeling of the physical problem produces nonlinear set of partial differential equations corresponding to the momentum and energy equations that can be transformed into simultaneous system of ordinary differential equations with appropriate boundary conditions by applying similarity transformations. Shooting technique is used to solve the molded equations after adoption of Runge–Kutta–Fehlberg approach and ODE45 solver in MATLAB. A parametric analysis has been carried out to investigate the impacts of physical parameters that are considered in the current study. The attractive pattern studied the consequence of Brownian motion along with thermophoresis parameter. The outcomes of prominent fluid parameters, especially heat radiation, Lewis number, free stream velocity, chemical reaction, thermophoresis, and Brownian motion on the concentration, temperature, as well as velocity have been examined and are displayed through graphs and tables. The present study reveals that the temperature phenomenon enhances with an increase in radiation parameter, while nanoparticle concentration phenomenon reduces with an increase in chemical reaction parameter. 相似文献
8.
Present research article investigate the heat and mass transfer characteristics of unsteady magnetohydrodynamic Casson nanofluid flow between two parallel plates under the influence of viscous dissipation and first order homogeneous chemical reaction effects. The impacts of thermophoresis and Brownian motion are accounted in the nanofluid model to disclose the salient features of heat and mass transport phenomena. The present physical problem is examined under the presence of Lorentz forces to investigate the effects of magnetic field. Further, the viscous and Joule dissipation effects are considered to describe the heat transfer process. The non‐Newtonian behaviour of Casson nanofluid is distinguished from those of Newtonian fluids by considering the well‐established rheological Casson fluid model. The two‐dimensional partial differential equations governing the unsteady squeezing flow of Casson nanofluid are coupled and highly nonlinear in nature. Thus, similarity transformations are imposed on the conservation laws to obtain the nonlinear ordinary differential equations. Runge‐Kutta fourth order integration scheme with shooting method and bvp4c techniques have been used to solve the resulting nonlinear flow equations. Numerical results have been obtained and presented in the form of graphs and tables for various values of physical parameters. It is noticed from present investigation that, the concentration field is a decreasing function of thermophoresis parameter. Also, concentration profile enhances with raising Brownian motion parameter. Further, the present numerical results are compared with the analytical and semianalytical results and found to be in good agreement. 相似文献
9.
The key purpose of this article is to examine magnetohydrodynamics flow, generative/absorptive heat, and mass transfer of nanofluid flow past a wedge in the presence of viscous dissipation through a porous medium. The investigation is completely theoretical, and the present model expresses the influence of Brownian motion and thermophoresis using the nanofluid Buongiorno model. The fundamental model of partial differential equations is reframed into the structure of ordinary differential equations implementing the nondimensional similarity transformation, which are tackled through the fourth–fifth-order Runge–Kutta–Fehlberg algorithm together with the shooting scheme. The analysis of sundry nondimensional controlling parameters, such as magnetic parameter, Eckert number, heat generation/absorption parameter, porosity parameter, Brownian motion parameter, and thermophoresis parameter on velocity, temperature, and concentration profiles are discussed graphically. The effects of the physical factors on the rate of momentum and heat and mass transfer are also determined with appropriate analysis in terms of skin friction, Nusselt number, and Sherwood number. The outcomes illustrate that the local Nusselt number and local Sherwood number are reduced for higher values of the thermophoresis parameter. Besides, it is found that higher estimations of heat generation/absorption and viscous dissipation parameters increase temperature. Moreover, it is found that the temperature profile increases with the involvement of the Brownian motion parameter, while an opposite trend is observed in the concentration profile. A comparison is also provided for limiting cases to authenticate our obtained results. 相似文献
10.
The present study has been conducted to acquire the solutions for the flow problem of an incompressible nanofluid past a permeable inclined plate implanted in a porous medium. In this study, double‐diffusivity, Brownian motion, and thermophoresis as well as passive control nanoparticles have been studied. We employ Lie group transformation on the ruling equations to extract nonlinear ordinary differential equations and solve them numerically using the fourth‐order Runge‐Kutta method and shooting approach. The supremacy of affined parameters on temperature and velocity distributions has been exposed by means of tables and graphs. This investigation suggests that both fluid velocity and nanoparticle concentration are enhanced by the modified Dufour parameter and the thermophoresis parameter. The assistance of the Lewis number intensifies the heat transport for suction. 相似文献
11.
Venkatesh Puneeth Sarpabhushana Manjunatha Bijjanal Jayanna Gireesha Sabir A. Shehzad 《亚洲传热研究》2021,50(8):7632-7653
The proposed model investigates three-dimensional bioconvective Sisko nanofluid flow under Robin's conditions. The Sisko nanofluid has versatile implications in drilling fluids, cement slurries, waterborne coatings, and so on. Furthermore, the inclusion of gyrotactic microorganisms prevents the deposition and agglomeration of the nanoparticles in the base fluid. Buongiorno's model is included to explore the behavior of Brownian motion and thermophoretic factors. The energy and mass transmissions along with the gyrotactic microorganism density are illustrated by the partial differential expression system with Robin's conditions. These are further reframed into an ordinary differential equation system with the aid of similarity transformation. The developing model is tackled by using the MAPLE inbuilt package BVP. The nanofluid acts as a good cooling agent for higher values of the thermophoresis parameter. Furthermore, the pseudoplastic nanofluid performs better than the dilatant nanofluid. The developed model is very useful in energy production and engineering products. 相似文献
12.
In this study, unsteady boundary layer flow with Casson nanofluid within the sight of chemical reaction toward a stretching sheet has been analyzed mathematically. The fundamental motivation behind the present examination is to research the influence of different fluid parameters, in particular, Casson fluid
13.
Double‐Diffusive Convective Transport in a Nanofluid‐Saturated Porous Layer with Cross Diffusion and Variation of Viscosity and Conductivity 
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下载免费PDF全文 The onset of double‐diffusive nanofluid convection in a fluid‐saturated horizontal porous layer is studied with thermal conductivity and viscosity dependent on the nanoparticle volume fraction. The Darcy model has been used for the porous medium, while the nanofluid incorporates the effects of Brownian motion along with thermophoresis. The nanofluid is assumed to be diluted and this enables the porous medium to be treated as a weakly heterogeneous medium with variation in the vertical direction of conductivity and viscosity. In addition, the thermal energy equation includes regular diffusion and cross diffusion terms. The linear stability analysis is based on the normal mode technique, while for nonlinear analysis, minimal representation of the truncated Fourier series representation involving only two terms has been used. It is found that for the stationary mode the Soret parameter, Dufour parameter, viscosity ratio, and conductivity ratio have a stabilizing effect, while the solutal Rayleigh number destabilizes the system. For the oscillatory mode, the Soret parameter, Dufour parameter, and viscosity ratio have a stabilizing effect while the solutal Rayleigh number and conductivity ratio destabilize the system. For steady finite amplitude motions, the heat and mass transport decreases with an increase in the values of the Dufour parameter and solutal Rayleigh number. The Soret parameter enhances the solute concentration Nusselt number while it retards the thermal Nusselt number and concentration Nusselt number. The viscosity ratio and conductivity ratio enhances the heat and mass transports. We also study the effect of time on transient Nusselt numbers which is found to be oscillatory when time is small. However, when time becomes very large, all three transient Nusselt values approach a steady value. © 2013 Wiley Periodicals, Inc. Heat Trans Asian Res, 43(7): 628–652, 2014; Published online 11 November 2013 in Wiley Online Library ( wileyonlinelibrary.com/journal/htj ). DOI 10.1002/htj.21102 相似文献
14.
The present study employs irreversibility analysis for the peristaltic movement of a nanofluid. The viscosity of the nanofluid is assumed to vary with the local concentration of colloidal particles. Impacts of thermophoresis, magnetic field, Brownian motion, Ohmic heating, viscous dissipation, and buoyant forces are considered in the flow analysis. Equations representing the flow and heat/mass transfer are prepared by employing Buongiorno's model for nanofluids. The lubrication approach is used to simplify the governing equations. The resulting system of differential equations is numerically solved with the aid of NDSolve in Mathematica. Results for entropy generation, Bejan number, velocity, temperature, and concentration are graphically presented. Outcomes show that entropy generation and temperature reduce by increasing the values of viscosity parameter. By increasing buoyancy forces due to temperature difference, the entropy generation increases, whereas the concentration profile shows a decreasing behavior. Maximum velocity reduces with an increment in the Hartman number. 相似文献
15.
Manangi Chamaraja Jayaprakash Kora Revanna Lalitha Konduru Sarada Deshmukh Ashok Reddy Arasaiah Arasaiah 《亚洲传热研究》2022,51(2):1809-1829
The properties of ferromagnetic fluids make them suitable for a wide range of applications, including loudspeakers, magnetic resonance imaging, computer hard drives, magnetic drug delivery, and magnetic hyperthermia. Owing to all such potential applications, the present research work is established to explain the stagnation point flow, heat, and mass transfer of Walters-B liquid in the presence of magnetic dipole, Brownian diffusion, and thermophoresis. To control the nanoparticles concentration at the surface, a passive control condition is employed. Using suitable similarity transformations, the governing equations are converted into nonlinear ordinary differential equations. Noticeable behavior of significant parameters on flow fields is studied graphically. The significant outcomes of the present study are that the increased values of viscoelastic parameter decline the velocity but an inverse trend is seen in heat transfer. The increased values of the Brownian motion parameter decline the heat transfer but a contrary trend is seen for augmented values of the thermophoresis parameter. The heat transfer rate is increased for rising values of radiation parameter and Biot number. The upward values of the thermophoresis parameter decline the rate of mass transfer. The escalating values of ferromagnetic interaction and velocity ratio parameters improve the skin friction. 相似文献
16.
The current study examines mixed (combined) convection stagnation‐point couple stress nanofluid over a stretched cylinder of variable thermal conductivity in the presence of viscous dissipation and internal heat source. The basic governing partial differential equations have been converted to coupled nonlinear differential equations by using adequate similarity transformations. By applying semi‐analytic technique (BVPh2.0), the equivalent ordinary differential equations are successfully solved and validated with a bvp4c solver. Graphs are presented to study the impact of various parameters on axial velocity, temperature, and volumetric nanofluid concentration profiles. The coefficient of skin friction (quantifying resistance) and the rate of heat and mass transfer on the surface due to flow variables are computed and explained. The axial velocity and momentum thickness are decreased with increasing couple stress parameter, whereas the reverse trend is noted with mixed convection and buoyancy ratio parameters. The temperature distribution increases for increasing Brownian motion and thermal conductivity parameter, whereas it decreases for increasing stagnation parameter. 相似文献
17.
Poshala Vijay Kumar Narsu Sivakumar Pankaj Shukla Putta Prakash Putta Durgaprasad Chekolu Murali Krishna Chakravarthula Siva Krishnam Raju Gottam Viswanatha Reddy 《亚洲传热研究》2023,52(6):4137-4157
This work examines the boundary flow difficulties of the past and the heat transfer properties of Blasius and Sakiadis flows under prescribed concentration flux and prescribed heat flux. The nanofluid is also taken into account in this model, along with impacts from Brownian motion and thermophoresis. The modified system governing partial differential equations is numerically solved by using the R-K method along with the shooting technique. Various values of physical quantities like thermophoresis parameter, Brownian motion parameter, Eckert number, thermal radiation parameter, heat source parameter, and magnetic field parameter along with the were calculated using the temperature, concentration, and velocity profiles. Finally, we demonstrated how the Brownian motion, radiation, and thermophoresis parameters can significantly increase the temperature distributions. The concentration distributions were decelerated with an increase in Brownian motion parameters for both Blasius and Sakiadis cases. 相似文献
18.
19.
In the current study, we use Galerkin finite‐element simulation to analyze the concept of triple diffusive flow with magnetic field effect toward a power law stretching sheet. The fluid comprises dissolved solutal particles and nanoparticles in the base fluid. The three important mechanisms that are responsible for rise in phenomenon of convective transportation are diffusophoresis, thermophoresis along with Brownian motion have been considered. Recently, the proposed nanoparticles' mass flux and heat flux boundary conditions have been imposed. Nanoparticle mass transportation, solutal mass transportation with heat transportation for prominent physical parameters, such as stretching parameter, magnetic influence parameter, thermophoresis parameter, and Brownian motion parameter are calculated. To further verify and understand the strength of the relationship between heat transportation rate and controlling parameters, the multiple regression process is used. The finite difference approach was adopted to numerically solve the nonlinear governing equations and the linked boundary conditions. In the present study, we used MATLAB software for finding the final outcomes and relating the concluding results for with extant outcomes in the literature as a limiting case in the absence of the magnetic intensity parameter and an excellent agreement was noted. It was observed that the magnetic field has a positive effect on heat and mass transfer. This study also helps in understanding and thus controlling the velocity of the flow along with solutal depositions, which has a significant engineering application in the process of extrusion. The findings of the present study help to control the rate of heat and mass transfer, aiding manufacturing companies in obtaining the desired quality of product. 相似文献
20.
Natural Convection Flow of a Nanofluid along a Vertical Plate with Streamwise Temperature Variations 下载免费PDF全文
下载免费PDF全文 This work is devoted to study the natural convection boundary‐layer flow of nanofluids along a vertical flat plate with the effect of sinusoidal surface temperature variations. The model utilized for the nanofluid incorporates the effects of Brownian motion and thermophoresis. An appropriate set of dimensionless variables is used to transform the governing equations of the problem into a nonsimilar form. The obtained nonsimilar equations have the property that they reduce to various special cases previously considered in the open literature. An adequate and efficient implicit, tri‐diagonal finite difference method is employed for the numerical solution of the obtained equations. Comparison with previously published work is performed and the results are found to be in excellent agreement. A representative set of numerical results for the dimensionless velocity, temperature and nanoparticle volume fraction, as well as the surface shear stress, rates of heat and nanoparticle volume fraction have been presented graphically and discussed to show interesting features of the solutions. 相似文献