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31.
This work is concerned with the two-dimensional boundary layer flow of an upper-convected Maxwell (UCM) fluid in a channel
with chemical reaction. The walls of the channel are porous. Employing similarity transformations the governing non-linear
partial differential equations are reduced into non-linear ordinary differential equations. The resulting ordinary differential
equations are solved analytically using homotopy analysis method (HAM). Expressions for series solutions are derived. The
convergence of the obtained series solutions are shown explicitly. The effects of Reynold’s number Re, Deborah number De, Schmidt number Sc and chemical reaction parameter γ on the velocity and the concentration fields are shown through graphs and discussed. 相似文献
32.
This Letter looks at the rotating flow of a second grade fluid past a porous shrinking surface. The fluid is electrically conducting in the presence of a constant applied magnetic field. The governing partial differential equations are first reduced into ordinary differential equations and then solved by homotopy analysis method (HAM). Convergence of the series solution is shown explicitly. In addition, the obtained results are illustrated graphically to indicate the effects of the pertinent physical parameters. 相似文献
33.
The effect of variable viscosity on the peristaltic flow of a Newtonian fluid in an asymmetric channel has been discussed. Asymmetry in the flow is induced due to travelling waves of different phase and amplitude which propagate along the channel walls. A long wavelength approximation is used in the flow analysis. Closed form analytic solutions for velocity components and longitudinal pressure gradient are obtained. The study also shows that, in addition to the effect of mean flow parameter, the wave amplitude also effect the peristaltic flow. This effect is noticeable in the pressure rise and frictional forces per wavelength through numerical integration. 相似文献
34.
In this article, analysis is presented to study the effect of Hall current on the rotating flow of a non-Newtonian fluid in
a porous medium taking into consideration the modified Darcy's law. The Oldroyd-B fluid model is used to characterize the
non-Newtonian fluid behavior. The governing equations for unsteady rotating flow have been modeled in a porous medium. The
analysis includes the flows induced by general periodic oscillations and elliptic harmonic oscillations of a plate. The effect
of the various emerging parameters is discussed on the velocity distribution. The analytical results are confirmed mathematically
by giving comparison with previous studies in the literature. It is observed that the velocity distribution increases with
an increase of Hall parameter. The behavior of permeability is similar to that of the Hall parameter. 相似文献
35.
Altaf HussainSardar Sikandar Hayat M.A. Choudhry 《Physica B: Condensed Matter》2011,406(10):1961-1965
The electronic structures and optical properties of TiAl intermetallic alloy system are studied by the first-principle orthogonalized linear combination of atomic orbitals method. Results on the band structure, total and partial density of states, localization index, effective atomic charges, and optical conductivity are presented and discussed in detail. Total density of states spectra reveal that (near the Fermi level) the majority of the contribution is from Ti-3d states. The effective charge calculations show an average charge transfer of 0.52 electrons from Ti to Al in primitive cell calculations of TiAl alloy. On the other hand, calculations using supercell approach reveal an average charge transfer of 0.48 electrons from Ti to Al. The localization index calculations, of primitive cell as well as of supercell, show the presence of relatively localized states even above the Fermi level for this alloy. The calculated optical conductivity spectra of TiAl alloy are rich in structures, showing the highest peak at 5.73 eV for supercell calculations. Calculations of the imaginary part of the linear dielectric function show a prominent peak at 5.71 eV and a plateau in the range 1.1-3.5 eV. 相似文献
36.
In this paper, the dynamical behavior of a hybrid switching SIS epidemic model with vaccination and Lévy jumps is considered. Besides a standard geometric Brownian motion, another two driving processes are taken into account: a stationary Poisson point process and a continuous time finite-state Markov chain. Firstly, we establish sufficient conditions for persistence in the mean of the disease. Then we obtain sufficient conditions for extinction of the disease. In addition, we also establish sufficient conditions for the existence of positive recurrence of the solutions to the model by constructing a suitable stochastic Lyapunov function with regime switching. 相似文献
37.
Exact analytical solutions for a class of unsteady unidirectional flows of an incompressible second-order fluid are constructed. The flows are generated impulsively from rest by motion of a plate or two plates or by sudden application of a pressure gradient. Expressions for velocity, flux and skin friction are obtained for both large and small times. It is found that large and small times solutions are dependent on the coefficient of viscoelasticity. The solutions corresponding to Newtonian fluids can be easily obtained from those for fluids of second order by letting the viscoelastic parameter to be zero. 相似文献
38.
The recurrence tracking microscope for probing nanostructures on a surface is based on the quantum recurrence phenomenon. We report that condensed atoms bouncing off on the atomic mirror, connected to a cantilever, modify the quantum recurrences. The times at which the recurrences occur depend on the initial energy of the bouncing condensates above the atomic mirror, which change with the density of condensed atoms. 相似文献
39.
The heat transfer analysis on the laminar flow of an incompressible third grade fluid through a porous flat channel is examined. The lower plate is assumed to be at a higher temperature than the upper plate. Analytical solution for temperature distribution is obtained for various values of the controlling parameters and discussed. The obtained analytical solution is also compared with the numerical solution. The comparison shows the fact that the accuracy is remarkable. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
40.
The effect of variable viscosity on the peristaltic motion of MHD third‐order fluid in a channel is studied using slip condition. The series solution for stream function, longitudinal velocity and pressure gradient are first derived and then discussed in detail. The pressure rise and frictional forces are monitored through numerical integration. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献