共查询到20条相似文献，搜索用时 0 毫秒
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An attempt has been made to investigate the problem of a natural convective radiative flow past an impulsively moving vertical plate with uniform mass and heat flux in the existence of the thermal diffusion effect. The resulting governing equations are solved by the Laplace transform technique in closed form. Effects of radiation, Prandtl number, Soret number, Grashof number, modified Grashof number, and Schmidt number are studied on temperature field, concentration field, velocity field, plate temperature, plate concentration, skin friction, and are demonstrated through graphs. The present study reveals that an intensification of the thermal radiation effect causes a downfall in the fluid temperature, plate temperature, and skin friction, but a contradictory outcome is spotted for plate concentration. One of the significant findings of this study includes that the increasing thermo-diffusion effect hikes the concentration and frictional resistance of the field. 相似文献
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This research focuses on studying the effects of heat and mass transfer convective flow passing through an infinite vertical plate embedded in porous media under radiation and chemical reaction with constant heat and mass flux. A magnetic field of strength is functional throughout the fluid region. The novelty of the present work is to examine the heat and mass transfer magnetohydrodynamics flow in the presence of thermal radiation. The equations governing the flow, heat and mass transfer are solved analytically using the perturbation technique. Expressions for velocity, temperature, concentration, skin-friction, Nusselt, and Sherwood numbers are obtained. The influence of physical parameters on the flow domain is described graphically and in tabular form. It is found that increase in radiation parameter reduces the velocity and temperature. Moreover, internal friction of the plate decreased with increasing values of radiation parameter. 相似文献
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A more integral human thermal model was built by combining the human thermal cylindrical model and the manual poly‐segment thermal model. Finite element methods (FEM) was used to define the body thermal model. It was in good agreement with the experimental results. The results show: the experimental results are consistent with the calculated value, when suitable blood flux is taken into consideration. The blood flux is in a certain range when the manual temperature is stable. Blood flux is the major factor in the manual temperature field. Body temperature and intake artery temperature have little effect on the hand temperature. © 2008 Wiley Periodicals, Inc. Heat Trans Asian Res, 37(2): 94–100, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.20187 相似文献
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The study of squeezing flow has attracted considerable interest in recent years for its important applications in industrial, biomedical and engineering domains such as fibre-reinforced, cell squeeze technology. The aim of this study is to analyze the flow and heat transfer of a squeezed particle fluid with thermal radiation effects between parallel plates. The governing partial differentials are reduced to ordinary differential equations by a similarity transformation and solved numerically using the finite difference method. The effects of different physical parameters on the velocity and temperature profiles are discussed with the help of graphs coupled with comprehensive discussions. The results indicate that the thermal radiation parameter enhanced the fluid and particle temperature distribution and for the plate oscillation case, reverse flow is observed. To show the biological relevance of the analysis, the results obtained analyzed the influence of the squeezed artery wall on the suspension blood flow for normal and diseased blood using the experimental data from the published literature. Finally, a comparison between the present similarity solutions and previously published results shows the accuracy of the current results. 相似文献
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This exploration reports the analysis of thermal and species transportation to yields manifesting non-Newtonian material flowing over the linear stretching sheet. Phenomena of heat transport are presented via Cattaneo–Christov heat flux definition. Mass transportation is modeled by engaging the traditional Fick's second law with updated model of mass flux including the species relaxation time. Moreover, Joule heating and radiation contribution to thermal transmission are also considered. The significant contribution of diffusion-thermo and thermos-diffusion is engaged in thermal and species transmission. Physical depiction of the considered scenario is modeled via boundary layer approximation. Similarity analysis has been made to transfigure the system of modeled partial differential equations into respective ordinary differential equations. Afterwards, transformed physical expressions are computed for the momentum, thermal, and species transportation inside the boundary layer. 相似文献
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M. M. Awad 《亚洲传热研究》2021,50(2):1252-1253
This commentary shows that the correct units of mass expansion coefficient (βc) must be m3/mol (ie, the inverse of the concentration [C] units) so that the product βc(C − C∞) is dimensionless in the momentum equation. Also, the correct units of magnetic field strength (B0) must be Tesla so that the last term in RHS of the momentum equation has the units of m/s2. In addition, the correct units of dynamic viscosity (μ) must be kg/m·s so that the last term in RHS of the energy equation has the units of K·s. These correct units must be used too in the converted momentum and energy equations after introducing the stream function Ψ(x, y). Using these wrong units will cause some dimensionless parameters such as Grashof number (Gb) and magnetic parameter (M) will be dimensional. 相似文献
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讨论了地源热泵的地热换热器的三种传热模型,给出了各自的解析式,并进行了比较,指明了各自的适用范围与条件,指出准三维模型能够提供更准确的数据。 相似文献
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The problem of a hydromagnetic convective flow of an electrically incompressible viscous conducting fluid past a uniformly moving vertical porous plate is investigated analytically, taking into consideration radiation and thermal diffusion effects. A constant suction velocity is applied to the plate. A uniformly strong magnetic field is supposed to be applied normally to the plate and directed into the fluid region. To find a solution to the problem, an asymptotic series expansion method is used. The effects of thermal diffusion, magnetic field, porosity parameter, thermal radiation, and Grashof number are mainly focused on the discussion of the current problem. Increasing Soret number (Sr) hikes the velocity profile and skin friction but declines Sherwood number. Also, it has been found that, when the magnetic parameter (M) increased, the fluid velocity and the concentration profile decreased. The current results show a good deal of agreement with previously published work. The findings of this study could be relevant in a variety of applications, including diffusion processes involving molecular diffusion of species with molar concentration. 相似文献
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This paper examined the mechanism of both positive and negative effects of Soret‐Dufour with heat and mass transfer processes over an accelerating permeable surface. The partial differential flow equations were simplified using similarity variables, and the resulting equations were solved numerically using the spectral homotopy analysis method (SHAM). The SHAM is used in separating nonlinear equations into linear and nonlinear. The physics of each pertinent flow parameters was used to examine their influence on velocity, temperature, and concentration fields. The effect of Soret‐Dufour was examined separately, and its negative effect was used to determine its influence on velocity, temperature, and concentration fields. The result revealed that positive Soret‐Dufour enhances the boundary layer, whereas negative Soret‐Dufour parameter decreases the boundary layer. The result presented in this paper is in good agreement with existing works in literature. 相似文献
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In this paper, the effects of Dufour and Soret numbers on the peristaltic motion of a non-Newtonian micropolar fluid are discussed. The motion inside a nonuniform vertical channel under the effect of the uniform magnetic field is considered. The Ohmic and elastic dissipations, as well as heat generation and chemical reaction, are taken into account. The problem is modulated mathematically by using continuity, momentum, angular momentum, and heat and mass transfer equations. The nonlinear partial differential equations describing these equations are written in terms of the physical parameters of the problem. The equations are transformed from the laboratory frame to the wave frame and then written in dimensionless form. The approximations of long wavelength and small Reynolds number are applied, then the equations are solved by using the homotopy perturbation method. The velocities, stream function, temperature, and concentration distributions are obtained as functions of the physical parameters of the problem. The effect of these parameters on the obtained solutions are computed mathematically and illustrated graphically through a set of figures. It is found that the parameters play an important role in controlling the solutions. It is found that the stream function decreases by increasing both non-Newtonian and micropolar parameters on the left side of the channel and vice versa occurs on the right side. 相似文献
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利用净辐射方法建立了聚光型TPV系统的光谱辐射换热模型,讨论了聚光挡板对数的影响。结果表明,对该文讨论的系统结构,在电池面积小于一定值时,采用挡板的系统中可转换净辐射密度均明显大于无挡板的情况,且电池面积越小,净辐射密度越大;随可转换净辐射功率(与电池输出功率成正比)的减小,对应于最小电池面积和最大光谱效率的系统逐渐由开始的二对挡板转变成四对挡板的系统。 相似文献
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The objective of this work is to develop an improved model of the human thermal system. The features included are important to solve real problems: 3D heat conduction, the use of elliptical cylinders to adequately approximate body geometry, the careful representation of tissues and important organs, and the flexibility of the computational implementation. Focus is on the passive system, which is composed by 15 cylindrical elements and it includes heat transfer between large arteries and veins. The results of thermal neutrality and transient simulations are in excellent agreement with experimental data, indicating that the model represents adequately the behavior of the human thermal system. 相似文献