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An analytical technique known as the homotopy analysis method is used to acquire solutions for magnetohydrodynamic 3‐D motion of a viscous nanofluid over a saturated porous medium with a heat source and thermal radiation. The governing nonlinear partial differential equations are changed to ordinary differential equations employing appropriate transformations. Validation of the present result is done with the help of error analysis for flow and temperature. The influences of pertinent parameters on momentum, energy, and Nusselt number are studied and discussed. The major findings are: the velocity of the nanofluid is affected by the nanoparticle volume fraction and the thickness of the thermal boundary layer becomes thinner and thinner subject to sink, whereas the effect is revered in case of the source. 相似文献
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This analysis intends to address the coupled effect of phase change heat transfer, thermal radiation, and viscous heating on the MHD flow of an incompressible chemically reactive nanofluid in the vicinity of the stagnation point toward the stretching surface, taking a Jeffrey fluid as the base fluid. Convergent analytical solutions for the nonlinear boundary layer equations are obtained by the successive application of scaling variables and the highly efficacious homotopy analysis method. Error analysis is implemented to endorse the convergence of the solutions. Through parametric examination, influence of various physical parameters occurring in analysis of the profiles of velocity, temperature, and nanoparticle concentration, coefficient of surface drag, rates of mass and heat transfer is explored pictorially. The Deborah number and the melting parameter are found to enhance velocity, and the associated momentum boundary layers are thicker, whereas the magnetic field depreciates the flow rate. Temperature is observed to enhance with the thermophoresis parameter, Prandtl number and Eckert number, whereas a reduction is seen with the thermal radiation parameter and Brownian motion parameter. Nanoparticle concentration is depleted by the chemical reaction parameter, the thermophoresis parameter, and the Lewis number. 相似文献
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In this study, a mixed convection flow over a nonlinearly stretching sheet of variable thickness is examined. Governing equations are modeled and transformed into dimensionless forms by utilizing dimensionless variables. For further investigation, dimensionless, coupled nonlinear differential equations with suitable boundary conditions are numerically solved using the Matlab built‐in function bvp5c tool, and analytical solutions are also computed using the homotopy analysis method. A comparative study is carried out to check the efficiency and accurateness of the proposed solution methodologies. Convergence of the derived series solutions is carefully checked. The impact of wall thickness parameter, velocity index parameter, Prandtl number, and mixed convection parameter on nondimensional velocity, temperature, skin friction coefficient, and local Nusselt number is examined. The novelty of this examination is that the dimensionless equations are self‐similar in the presence of mixed convection. These self‐similar equations are acquired by establishing a relationship between velocity and temperature power index parameters, and similarity solutions exist only for a particular form of variable surface temperature. 相似文献
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Adebowale M. Obalalu 《亚洲传热研究》2021,50(8):7988-8011
This study investigates the heat and mass transfer in an unsteady squeezing flow between parallel plates under the influence of novel variable diffusivity. In most of the literature, it is believed that the thermophysical properties of the fluid are unchanged. However, this present study bridges this gap by assuming that viscosity, conductivity, and diffusivity are all temperature-dependent. Physically, an appropriate analysis of thermophysical variables in such a system is required to achieve the best performance for effective heat and mass transfer processes. The equations controlled were first nondimensional and then simplified by a similarity transformation to ordinary nonlinear differential equations. The present study provides a fast convergent method on finite parallel plates, namely, the optimal homotopy analysis method (OHAM) and spectral collocation method (SCM) are used to analyze the fluid flow, heat, and mass transport. The graphical and table understanding is given via an error table and flow behavior of physical parameters. The result reveals that the SCM is more accurate than OHAM. However, the method employed in this paper offers excellent convergence solutions with good accuracy. The solution convergence is also discussed. In this type of problem, squeeze numbers play an important role and the rise in the squeezing parameter increases the fluid temperature. 相似文献
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The primary objective of the present paper is to investigate the novel aspect of nanofluid flow near the stagnation‐point past a permeable cylinder with chemical reaction. The prescribed surface heat and nanoparticle fluxes are also taken into account. The improved homotopy analysis method is introduced to obtain the recursively analytic solutions with high precision. The convergence of the obtained series solution is discussed explicitly. Besides, the effects of physically significant parameters on skin friction coefficient, local Nusselt number, local Sherwood number, as well as profiles of velocity, temperature, and nanoparticle volume fraction are examined and discussed in detail. It is found that the local Sherwood number increases when a chemical reaction occurs in the nanofluid. It is also indicated that the increase of the reaction rate parameter leads to a higher temperature and a lower nanoparticle volume fraction. 相似文献
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Magnetohydrodynamic (MHD) free‐surface flow and heat transfer of liquid metal around a cylinder under different Reynolds numbers were simulated numerically. The effects of the application of a magnetic field on wake and vortex shedding were analyzed. The characteristics of flow fields and temperature as well as Lorentz forces under two different Reynolds numbers were presented. The results showed that magnetic field could not only change substantially the flow pattern, but also suppress turbulent viscosity and surface renewal, which degraded heat transfer. Under the same Hartmann numbers, compared with the MHD‐flow and heat transfer of lower Reynolds numbers, the turbulence intensity and interaction between free surface and wake were still stronger for higher Reynolds numbers; consequently, the heat transfer was still high. © 2007 Wiley Periodicals, Inc. Heat Trans Asian Res, 37(1): 11–19, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.20189 相似文献
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In recent literature, the analysis of a combined convective flow over a cone has received a lot of attention. To explore the convection effects of flow over a cone in greater detail, in this investigation, we have considered a cone with a rough surface, which is entirely a new flow problem. Recent studies have shown the influence of roughness on fluid flow over several geometries, but flow over a rough conical surface has not been studied so far. In addition, we have analyzed the effects of nanoparticles, magnetohydrodynamic (MHD), and suction/blowing, which could have significant impacts on characteristics of fluid flow over the cone with a rough surface. Initially, the governing equations, which are partial differential equations with a high degree of nonlinearity, are nondimensionalized through Mangler's transformations. Later, linear equations are obtained via the method of quasilinearization, which is then solved numerically through finite difference approximations. The roughness of the cone's surface has notable effects on fluid flow, that too away from the origin. In fact, the roughness increases the friction at the cone's surface. Furthermore, the magnetic field applied at the wall increases the surface friction. Thus, the combination of roughness and MHD helps delay the boundary layer separation. On the other hand, the suction reduces the temperature of the fluid and increases the energy transport strength, while the thermophoresis parameter exhibits the contrary nature. Therefore, the combined consideration of these two could enhance energy transport strength in several industrial applications. 相似文献
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This study's primary objective is to analyze the entropy generation in an unsteady magnetohydrodynamics (MHD) Eyring–Powell nanofluid flow. A surface that stretched out exponentially induced flow. The influences of thermal radiation, thermophoresis, and Brownian motion are also taken into consideration. The mathematical formulation for the transport of mass, momentum, and heat described by a set of partial differential equation is used, which is then interpreted by embracing the homotopy analysis method and with a fourth-order precision program (bvp4c). Graphical results display the consequences of numerous parameters on velocity, temperature, concentration, and entropy generation. Moreover, escalating amounts of the magnetic parameter, thermal radiation parameter, Reynolds number, and Brinkman number improve the entropy profile of the nanofluid. The rate of heat flux and the mass flux conspicuously improves for non-Newtonian fluid as compared to Newtonian fluid. 相似文献
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In this study, a computational investigation is carried out to examine the interaction of heat generation/absorption with elastic deformation in a viscous hydromagnetic Walters’ B model past a stretching surface under the intensity of Newtonian heating. The model equations which are responsible for the motion of the fluid and heat interactions are reworked to ordinary differential equations by the appropriate similarity variables and solved via the homotopy analysis method. The parameters encountered were discussed through graphs and tables. The result reveals among others that the heat generation and Newtionian heating magnifies the temperature across the layer and makes quiescent fluid experience a thermal effect. 相似文献
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The present article looks at the theoretical analysis of a steady stagnation‐point flow with heat transfer of a third‐order fluid towards a stretching surface. The formulation of the problem has been carried out for a third order fluid and constructed partial differential equations are rehabilitated into ordinary differential equations. The consequential ordinary differential equations are solved analytically using the homotopy analysis method (HAM). Graphical illustrations are shown for various parameters involved in the flow equations. Numerical values of skin friction coefficients and heat flux are computed and presented through tables. © 2013 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley Online Library (wileyonlinelibrary.com/journal/htj). DOI 10.1002/htj.21042 相似文献
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This paper is focused on the analysis of heat and mass transfer radiative–convective fluid flow using quadratic multiple regression and numerical approach. The physical phenomenon is analyzed by utilizing partial differential equations (PDEs). Thermophysical properties, such as viscosity, thermal conductivity, and mass diffusivity, are varied and temperature-dependent. This study is unique because of its applications in magnetohydrodynamic power accelerators, drilling operators, and bioengineering. The governing PDEs are transformed into coupled nonlinear ordinary differential equations (ODEs). The transformed ODEs are solved numerically using the spectral homotopy analysis method. Also, a quadratic multiple regression analysis is performed on quantities of engineering interest to show the significance of the flow parameters. It is observed that the heat and mass transfer process is affected by nonlinear buoyancy impact. The Lorentz force produced by the imposed magnetic field decline the thickness of the hydrodynamic boundary layer. Findings revealed that the nonlinear convective parameter and variable thermophysical properties are greatly affected by the rate of heat and mass transfer. Previously published work was used to validate the present one, which conformed with it. The slope of linear regression through data points is adopted to show the rate of change in skin friction, Nusselt, and Sherwood numbers during the flow phenomenon. 相似文献
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Optimal Homotopy Asymptotic Solutions for Nonlinear Ordinary Differential Equations Arising in Flow and Heat Transfer due to Nonlinear Stretching Sheet 
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下载免费PDF全文 Optimal homotopy asymptotic method (OHAM) is used to obtain solutions for nonlinear ordinary differential equations (ODEs) arising in fluid flow and heat transfer at a nonlinear stretching sheet. The solutions for skin friction and temperature gradient for some special cases are tabulated and compared with the available numerical results in the literature. Moreover, OHAM is found to be very easy to use and the technique could be used for solving coupled nonlinear systems of ordinary differential equations arising in science and engineering. 相似文献
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In this work, application of the homotopy perturbation method (HPM) and an inverse solution for estimating unknown thermal parameters such as the variable thermal conductivity parameter (β), the thermogeometric parameter (K), and the nondimensional coefficient of thermal expansion (χ) in an annular fin subjected to thermal stresses is presented. Initially, to obtain the nondimensional temperature distribution from the heat equation, the forward method is employed using an approximate analytical solution based on HPM. Thereafter, a closed form solution for the temperature-dependent thermal stresses is obtained using the classical theory of thermoelasticity coupled with HPM solution containing the temperature distribution. Next, for satisfying a particular stress criterion which makes relevance in selecting appropriate configurations for selecting the finned system, unknown thermal parameters are obtained using an inverse approach based on the Nelder–Mead simplex search minimization technique. The objective function is taken as the sum of square of the residuals between the measured stress field and an initially guessed value which is updated iteratively. It is found that more than one type of temperature distribution may yield a given stress distribution, thereby giving rise to different fin efficiencies. The agreement between the actual and the predicted results was found to be satisfactory. 相似文献
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This article numerically scrutinizes magnetohydrodynamic flow of a nanofluid due to a nonlinearly curved stretching surface with third order slip flow conditions. The third order slip flow condition has not yet been discussed in fluid dynamics research. The mathematical modeling of the flow problem is given in partial differential equation form. The governing partial differential equations are transformed to high order ordinary differential equations using the similarity transformation and then solved numerically using a boundary value problem solver, bvp4c from Matlab software. The effect of the governing parameters on the flow of the velocity profile, concentration, and heat transfer characteristics are studied. Also graphs of the skin friction coefficient, local Nusselt number, and Sherwood number are drawn and their numerical values are tabulated. The numerical results of the study are compared with previously published articles in the limiting condition. The velocity of the flow field is reduced as the third order slip parameter and the first order slip parameter rises, but the velocity grows as the values of the second order slip flow parameter are elevated. The findings also indicate that the local Nusselt number is depreciated but local Sherwood numbers are elevated when the Soret and Dufour numbers are larger. 相似文献
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Solution of nonlinear boundary layer equation for flat plate via optimal homotopy asymptotic method 下载免费PDF全文
下载免费PDF全文 In this article, we use the optimal homotopy asymptotic method (OHAM) to compute the solution of two‐dimensional incompressible laminar boundary layer flow over a flat plate (Blasius problem). The obtained results for the stream function and velocity profile were comparable in terms of accuracy with that obtained by Esmaeilpour and Ganji (2007) who studied the same problem using the homotopy perturbation method and results obtained by using a numerical method (RK4). The good agreement obtained shows the effectiveness of OHAM. © 2013 Wiley Periodicals, Inc. Heat Trans Asian Res, 43(3): 197–203, 2014; Published online 19 June 2013 in Wiley Online Library ( wileyonlinelibrary.com/journal/htj ). DOI 10.1002/htj.21070 相似文献
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This paper presents the analytical study of heat and mass transfer in a two-dimensional time-dependent flow of Williamson nanofluid near a permeable stretching sheet by considering the effects of external magnetic field, viscous dissipation, Joule heating, thermal radiation, heat source, and chemical reaction. Suitable transformations are introduced to reformulate the governing equations and the boundary conditions convenient for computation. The resulting sets of nonlinear differential equations are then solved by the homotopy analysis method. The study on the effects of relevant parameters on fluid velocity, temperature, and concentration profiles is analyzed and presented in graphical and tabular forms. Upon comparison of the present study with respect to some other previous studies, a very good agreement is obtained. The study points out that the transfer of heat can substantially be enhanced by decreasing viscoelasticity of the fluid and the transfer of mass can be facilitated by increasing permeability of the stretching sheet. 相似文献
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This paper reveals the characteristics of mixed convection slip flow of an electrically conducting fluid over a wedge subject to temperature dependent viscosity and thermal conductivity variations. The system of dimensionless nonsimilar governing equations has been solved by an implicit finite difference method. We also use stream‐function formulation to reduce the governing equations into a convenient form, which are valid for small and large time regimes. These are solved employing the perturbation method for small time and the asymptotic method for large time. Numerical solutions yield a good agreement with the series solutions. Because of the increase in the mixed convection parameter, the peak of the velocity profile increases whereas the maximum temperature decreases. In contrast, the local skin‐friction coefficient and local Nusselt number are found to increase with the mixed convection parameter. For higher values of the velocity slip and temperature jump conditions, the local skin‐friction coefficient and the local Nusselt number are found to increase. The viscosity parameter enhances the local skin friction and the local Nusselt number. But the converse characteristic is observed for the thermal conductivity parameter. The results could be used in microelectromechanical systems, fabrication, melting of polymers, polishing of artificial heart valves, etc. 相似文献