Slip flow on a microcylinder

The purpose of this paper is to determine the heat transfer from a semi-infinite microcylinder under uniform axial flow in the slip regime. Following the treatments of Glauert and Lighthill (Proc Royal Soc 230A:188–203, 1955), and Crane (Ingenieur-Archiv 43:203–214, 1974), an asymptotic series solution is developed to account for the heat flux in terms of the Nusselt number for large axial distances along a cylinder maintained at constant temperature.     

Heat transfer on a microcylinder with slip

The purpose of this paper is to determine the heat transfer from a semi-infinite microcylinder under uniform axial flow in the slip regime. Following the treatments of Glauert and Lighthill (Proc Royal Soc 230A:188–203, 1955), and Crane (Ingenieur-Archiv 43:203–214, 1974), an asymptotic series solution is developed to account for the heat flux in terms of the Nusselt number for large axial distances along a cylinder maintained at constant temperature.     

Slip effects on MHD flow of a generalized Oldroyd-B fluid with fractional derivative

This paper presents an analysis for magnetohydrodynamic (MHD) flow of an incompressible generalized Oldroyd-B fluid inducing by an accelerating plate. Where the no-slip assumption between the wall and the fluid is no longer valid. The fractional calculus approach is introduced to establish the constitutive relationship of a viscoelastic fluid. Closed form solutions for velocity and shear stress are obtained in terms of Fox H-function by using the discrete Laplace transform of the sequential fractional derivatives. The solutions for no-slip condition and no magnetic field can be derived as the special cases. Furthermore, the effects of various parameters on the corresponding flow and shear stress characteristics are analyzed and discussed in detail.     

Slip effects on MHD flow of third order fluid in a planar channel

In this paper, the peristaltic flow of magnetohydrodynamic (MHD) third order fluid in a planar channel with slip condition is investigated. The solutions are derived under long wavelength and low Reynolds number approximations. Explicit expressions of stream function, longitudinal pressure gradient, longitudinal velocity, temperature and coefficient of heat transfer are given. The pumping and trapping phenomena are analyzed in the presence of MHD and slip effects. The effects of parameters on temperature distribution and heat transfer coefficient are discussed. A comparison is provided with the different existing cases.     

Uniform Slip Flow on a Cylinder

In this paper, we determine the shear stress along the entire length of a stationary cylinder having radius a, under uniform axisymmetric flow, with velocity U0, in the slip regime. Investigating motion at small and large axial distances, we employ asymptotic series techniques to obtain the shear stress coefficient in non-dimensional form. For intermediate regions, we obtain a solution using the Rayleigh approximation method. (© 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)     

A Note on Laminar Flow through a Porous Pipe with Slip

An analytic solution is developed for flow through a porouspipe when slip occurs. The solution should be useful in a rangeof problems in fluids engineering and chemical engineering.     

Slip effects in peristalsis

Taking slip condition into account the magnetohydrodynamic peristaltic flow in an asymmetric channel is theoretically analyzed. The analytic solutions for stream function, longitudinal pressure gradient, and temperature have been found in closed form by employing long wavelength and low Reynolds number approximations. A discussion for pressure rise and frictional forces is provided through numerical integration. Finally, the effects of various key parameters are discussed with the help of graphs and tables. © 2011 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 27: 1003–1015, 2011     

Time Domain Impedance Boundary Conditions for a Slip Mean FlowBoundary

In modeling the physical condition of an impedance boundary, the assumption of either particle displacement continuity (PDC) or particle normal velocity continuity (PVC) at the interface between the acoustic treatment and the adjacent fluid needs to be used. Although it is well accepted that the impedance boundary condition derived from the PDC is the appropriate impedance boundary condition when there is a slip mean flow at the liner surface, the time domain impedance boundary condition is however unstable due to the Kelvin‐Helmholtz instability associated with the ”vortex sheet.” In this paper, an effective time domain impedance boundary condition for a slip mean flow boundary is proposed and validated. Several relevant issues related to the PDC and PVC are discussed. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

滑移和感应磁场对Johnson-Segalman流体蠕动传输的影响

存在感应磁场和滑移条件下,研究Johnson-Segalman(J-S)流体在平面通道中的蠕动流.通道中的流动认为是对称的,并在剪切应力项中考虑了速度的滑移条件.首先给出问题的数学公式,然后在长波长和低Reynolds数近似下,求解该方程组得到摄动解,确定沿管道截面的压力增量、轴向速度、微转动分量、流函数、磁力函数、轴向感应磁场和电流密度分布公式.导出了小数值Weis-senberg数时解的表达式,分析并勾画出诸流动物理量的有趣变化.     

A Phase-field Model of Dislocations on Parallel Slip Planes

We establish a line-tension energy for dislocation networks concentrated in finitely many parallel slip planes as the limit of a Peierls-Nabarro energy. Dislocations in different planes interact depending on their distance. At intermediate distances a two-scale dislocation microstructure is optimal. (© 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)     

温差影响下的局部滑移接触行为的研究

针对不同温度装配件间接触界面的局部滑移问题,建立了三维稳态热弹性局部滑移接触的半解析求解模型.基于热弹性理论与热传导方程,构建了半空间受热流载荷和力载荷作用下的频响函数并建立了相应的影响系数矩阵.借助离散卷积-快速Fourier变换等数学工具,实现了针对高温压头与热弹性半空间局部滑移接触问题的高效求解.接触界面间的热量传递满足Fourier热传导定律,并且黏/滑状态由Coulomb定律确定.基于该半解析模型分析了不同荷载及温差对表面法向压力分布、摩擦力分布、刚体位移及接触区黏/滑演化行为的影响.研究结果表明,当法向荷载和切向荷载一定时,温差的上升会导致接触区域的减小,引起接触面法向压力及摩擦力的峰值增大,并且会显著影响黏着区与滑移区的分布情况.     

幂律速度运动表面上磁流体在驻点附近的滑移流动

从理论上研究了具有非线性延伸表面的磁流体在滑移流区的动量传输问题.通过Lie群变换把控制方程组转化为常微分方程组,利用同伦分析方法求得了问题的近似解析解.获得的级数解与文献中的数值解吻合得较好.另外,利用级数解分析滑移参数、磁场强度、速度比率参数、吸入喷注参数和幂律指数对流动的影响.结果显示这些参数对壁剪切力和边界层内流场有较大的影响.     

滑移垂直壁面驻点附近的混合对流边界层流动

就粘性不可压缩流体,研究垂直壁面的滑移,对壁面驻点附近稳定混合对流边界层流动的影响.假定表面温度和外部流动速度与到驻点的距离呈线性变化.首先,将偏微分的控制方程,转变为常微分方程组,然后应用打靶法进行数值求解.对不同数值的控制参数,按分顺流和逆流两种情况,分析和讨论了流动特性和热传导特征.结果表明,逆流时,在浮力参数的某一范围内出现双解;顺流时,解是唯一的.一般而言,速度滑移导致壁面热传导率增大,而热滑移使之减小.     

Slip of a rigid cylinder along a viscoelastic foundation in the presence of friction

The problem of the slip of a rigid infinitely long cylinder along a viscoelastic foundation in the presence of friction forces dependent on the slip rate is solved in a linear quasistatic arrangement. The effect of the rheological characteristics of the foundation material and other factors on the point displacement of the surface in front of the moving cylinder is studied. Rather good agreement is obtained between theoretical and experimental data.Institute of Mechanics of Metal-Polymer Systems, Academy of Sciences of the Belorussian SSR, Gomel'. Translated from Mekhanika Polimerov, No. 6, pp. 1058–1064, November–December, 1974.     

Remarks on Vanishing Viscosity Limits for the 3D Navier-Stokes Equations with a Slip Boundary Condition

The authors study vanishing viscosity limits of solutions to the 3-dimensional incompressible Navier-Stokes system in general smooth domains with curved boundaries for a class of slip boundary conditions. In contrast to the case of flat boundaries, where the uniform convergence in super-norm can be obtained, the asymptotic behavior of viscous solutions for small viscosity depends on the curvature of the boundary in general. It is shown, in particular, that the viscous solution converges to that of the ideal Euler equations in C([0, T];H1(Ω)) provided that the initial vorticity vanishes on the boundary of the domain.     

微极流体蠕动泵经由滑移边界管道输送的Stokes流动

计及管道边界条件滑移的影响,研究微极流体蠕动泵,经由圆柱形管道输运的Stokes流动.壁面运动的控制方程为正弦波方程.使用润滑理论,得到了轴向速度、微转动向量、流函数、压力梯度、摩擦力和机械效率的解析数值解.用图形表示出构成参数,如像耦合参数、微极参数和表征蠕流泵特性的滑移参数、摩擦力和俘获现象的影响.数值计算表明,当耦合参数较大时,需要蠕动泵的压力更大,而微极参数和滑移参数正相反.俘获团块的大小随耦合参数和微极参数的减小而缩小,而随滑移参数的增大而缩小.     

存在滑移时两圆球间的幂律流体挤压流动

基于Reynolds润滑理论分析了壁面滑移对任意圆球颗粒间幂律流体的挤压流动的影响。研究表明有壁面滑移时挤压流动的粘性力可通过引进本文定义的滑移修正系数分离出无滑移解。推导出的挤压力滑移修正系数是一积分表达式，依赖于滑移参数、幂律指数、球间隙和积分上限。一般地壁面滑移导致粘性力减小，粘性力的减小量随幂律指数的增大而增大，表明壁面滑移对剪切增稠流变材料有更大的影响；粘性力的减小量还随着滑移参数的增大而增加，而这恰与假设相符合；粘性力的减小量又随球间隙减小或积分上限的增大（从液桥情况到完全浸渍）而减小直到趋于常数，这一特性在离散元模拟时可以有效地减少计算量。     

Applications of a formula on Beltrami flow

In this note, we obtain uniqueness results for Beltrami flow in both bounded and unbounded domain with nonempty boundary by establishing an elementary but useful formula involving operators div and curl. We also use this formula to deal with Maxwell and Stokes eigenvalue problems.     

Local Artificial Boundary Conditions for the Incompressible Viscous Flow in a Slip Channel

1.IntroductionManyboundaxyvaJueproblemsofpartialdiffereotialequationsinvo1vingunboundeddomainoccurinmanyareasofapplications,e-g.lfluidflowaroundobstacles,couplingofstructureswithfoundationandsoon.Forgettingthenumericalsolutionsoftheproblemsonunboundeddomian,anaturalapproachistocutoffanunboundedpartofthedomainbyintroducinganartificialboundaryandsetupanaPpropriatear-tificialboundaryconditiononthearti%ialboundaryThentheoriginalproblemisapproximatedbyaproblemonbou.d.dfdomain.Inthelastteny6aJrs,b…