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1.
Peristaltic transport of a Jeffrey fluid under the effect of magnetic field in an asymmetric channel
M. Kothandapani 《International Journal of Non》2008,43(9):915-924
The peristaltic flow of a Jeffrey fluid in an asymmetric channel is studied under long wavelength and low Reynolds number assumptions. The fluid is electrically conducting by a transverse magnetic field. The channel asymmetry is produced by choosing the peristaltic wave train on the walls to have different amplitudes and phase. The flow is investigated in a wave frame of reference moving with the velocity of the wave. The expressions for stream function, axial velocity and axial pressure gradient have been obtained. The effects of various emerging parameters on the flow characteristics are shown and discussed with the help of graphs. The pumping characteristics, axial pressure gradient and trapping phenomenon have been studied. Comparison of various wave forms (namely sinusoidal, triangular, square and trapezoidal) on the flow is discussed. 相似文献
2.
The present analysis discusses the peristaltic flow of a nanofluid in a diverging tube. This is the first article on the peristaltic
flow in nanofluids. The governing equations for nanofluid are modelled in cylindrical coordinates system. The flow is investigated
in a wave frame of reference moving with velocity of the wave c. Temperature and nanoparticle equations are coupled so Homotopy perturbation method is used to calculate the solutions of
temperature and nanoparticle equations, while exact solutions have been calculated for velocity profile and pressure gradient.
The solution depends on Brownian motion number N
b
, thermophoresis number N
t
, local temperature Grashof number B
r
and local nanoparticle Grashof number G
r
. The effects of various emerging parameters are investigated for five different peristaltic waves. It is observed that the
pressure rise decreases with the increase in thermophoresis number N
t
. Increase in the Brownian motion parameter N
b
and the thermophoresis parameter N
t
temperature profile increases. Streamlines have been plotted at the end of the article. 相似文献
3.
This study investigates the peristaltic flow of Eyring–Powell fluid in an endoscope. The governing equations for Eyring–Powell
are modeled in cylindrical coordinates under the assumption of long wavelength and low Reynolds number approximation. The
resulting nonlinear differential equations are solved analytically and numerically by employing perturbation method and shooting
technique. Numerical integration have been done for pressure rise and frictional forces. Comparative study have been made
for both the solutions to see the validity of the results. The effects of various emerging parameters are investigated for
five different peristaltic waves. (Basically peristaltic phenomena is a natural phenomena so it is not necessary that peristaltic
wave be always a sinusoidal wave it could be multisinusoidal, triangular, trapezoidal and square waves for example heartbeats.)
Streamlines have been plotted at the end of the article. 相似文献
4.
Fluid mechanical peristaltic transport through esophagus is studied in the paper.A mathematical model has been developed to study the peristaltic transport of a rheological fluid for arbitrary wave shapes and tube lengths.The Ostwald-de Waele power law of a viscous fluid is considered here to depict the non-Newtonian behaviour of the fluid.The model is formulated and analyzed specifically to explore some important information concerning the movement of food bolus through esophagus.The analysis is carried out by using the lubrication theory.The study is particularly suitable for the cases where the Reynolds number is small.The esophagus is treated as a circular tube through which the transport of food bolus takes place by periodic contraction of the esophageal wall.Variation of different variables concerned with the transport phenomena such as pressure,flow velocities,particle trajectory,and reflux is investigated for a single wave as well as a train of periodic peristaltic waves.The locally variable pressure is seen to be highly sensitive to the flow index "n".The study clearly shows that continuous fluid transport for Newtonian/rheological fluids by wave train propagation is more effective than widely spaced single wave propagation in the case of peristaltic movement of food bolus in the esophagus. 相似文献
5.
In the present study, we investigated the effects of slip and induced magnetic field on the peristaltic flow of a Jeffrey fluid in an asymmetric channel. The governing two‐dimensional equations for momentum, magnetic force function and energy are simplified by using the assumptions of long wavelength and low but finite Reynolds number. The reduced problem has been solved by Adomian decomposition method (ADM) and closed form solutions have been presented. Further, the exact solution of the proposed problem has also been computed and the mathematical comparison shows that both solutions are almost similar. The effects of pertinent parameters on the pressure rise per wavelength are investigated using numerical integration. The expressions for pressure rise, friction force, velocity, temperature, magnetic force function and the stream lines against various physical parameters of interest are shown graphically. Moreover, the behavior of different kinds of wave shape are also discussed. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
6.
In this article couple stress fluid have been considered for the peristaltic flow of chyme in intestine. Problem under consideration have been formulated assuming that two non-periodic sinusoidal wave of different wavelength propagate with same speed c along the outer wall of the tube. Governing equations have been simplified under the assumptions of long wavelength and low Reynolds number approximation (such assumption are consistent that Re (Reynold number) is very small and long wavelength approximation also exists in the small intestine). Exact solutions have been evaluated for velocity and pressure rise. Physical behaviour of different parameter of couple stress fluid have been presented graphically for velocity, pressure rise, pressure gradient and frictional forces. The stream lines are also made against different parameters. 相似文献
7.
In this paper, we study the interaction of peristalsis with heat transfer for the flow of a viscous fluid in a vertical porous annular region between two concentric tubes. Long wavelength approximation (that is, the wavelength of the peristaltic wave is large in comparison with the radius of the tube) is used to linearise the governing equations. Using the perturbation method, the solutions are obtained for the velocity and the temperature fields. Also, the closed form expressions are derived for the pressure-flow relationship and the heat transfer at the wall. The effect of pressure drop on flux is observed to be almost negligible for peristaltic waves of large amplitude; however, the mean flux is found to increase by 10-12% as the free convection parameter increases from 1 to 2. Also, the heat transfer at the wall is affected significantly by the amplitude of the peristaltic wave. This warrants further study on the effects of peristalsis on the flow and heat transfer characteristics. 相似文献
8.
In the present paper we discuss the magnetohydrodynamic (MHD) peristaltic flow of a hyperbolic tangent fluid model in a vertical asymmetric channel under a zero Reynolds number and long wavelength approximation. Exact solution of the temperature equation in the absence of dissipation term has been computed and the analytical ex- pression for stream function and axial pressure gradient are established. The flow is analyzed in a wave frame of reference moving with the velocity of wave. The expression for pressure rise has been computed numerically. The physical features of pertinent parameters are analyzed by plotting graphs and discussed in detail. 相似文献
9.
In the present investigation we have presented the peristaltic flow of a linear Maxwell model through porous boundaries in
a porous medium. The governing non-dimensional partial differential are solved in wave frame by using regular perturbation
method and assumed form of solution. We have discussed the problem only for free pumping case. The effects of various physical
parameters involved in the problem have been investigated and shown graphically. 相似文献
10.
In the present article, we have studied the effects of inclined magnetic field on the peristaltic flow of Jeffrey fluid through the gap between two coaxial inclined tubes. The inner tube is rigid, whereas the outer tube has sinusoidal wave traveling down its wall. The governing equations are simplified using long wave length and low Reynolds number approximations. Exact and numerical solutions have been derived for velocity profile. The expressions for pressure rise and friction force are calculated using numerical integration. Graphical results and trapping phenomenon is presented at the end of the article to see the physical behavior of different parameters. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
11.
In the present investigation, we have studied the effects of mixed convection heat and mass transfer on peristaltic flow of
Williamson fluid model in a vertical annulus. The governing equations of Williamson fluid model are simplified using the assumptions
of long wavelength and low Reynold’s number. An approximated analytical and numerical solutions are found for the velocity
field using (i) Perturbation method (ii) Shooting method. The comparisons of analytical and numerical solutions have been
presented. The expressions for pressure rise, velocity against various physical parameter are discussed through graphs. 相似文献
12.
Yongqi Wang Tasawar Hayat Kolumban Hutter 《Theoretical and Computational Fluid Dynamics》2007,21(5):369-380
To understand theoretically the flow properties of physiological fluids we have considered as a model the peristaltic motion
of a Johnson–Segalman fluid in a tube with a sinusoidal wave traveling down its wall. The perturbation solution for the stream
function is obtained for large wavelength and small Weissenberg number. The expressions for the axial velocity, pressure gradient,
and pressure rise per wavelength are also constructed. The general solution of the governing nonlinear partial differential
equation is given using a transformation method. The numerical solution is also obtained and is compared with the perturbation
solution. Numerical results are demonstrated for various values of the physical parameters of interest.
相似文献
13.
Summary To understand theoretically the flow properties of physiological fluids, we have considered as a model the peristaltic motion of a power law fluid in a tube, with a sinusoidal wave of small amplitude travelling down its wall. The solution for the stream function is obtained as a power series in terms of the amplitude of the wave. The stream function and the velocity components are evaluated by solving numerically two point boundary value problems with a singular point at the origin. The influence of the applied pressure gradient along with non-Newtonian parameters on the streamlines and velocity profiles are discussed in detail. 相似文献
14.
Miroslav Kranyš 《Archive for Rational Mechanics and Analysis》1972,48(4):274-301
The signal and phase velocities (and their frequency dependence) for all possible plane waves in a relativistic gas (of molecules or photons) with dissipation have been determined from the linearized relativistic 13-moment theory. For each direction in 3-space, and for each frequency, one transverse and two longitudinal waves were found. (In addition, some waves are associated with the mass flow and have the mass flow speed.) Of the longitudinal waves, the fast one is a pressure (sound) wave. It is accompanied by a slow longitudinal thermal dissipation wave and a transverse viscous dissipation wave. The pressure wave has a velocity larger than the Laplace adiabatic speed of sound, while the two dissipation waves have a velocity less than the Laplace speed. All the speeds have been expressed explicitly in terms of quantities associated with the state of equilibrium which existed before passage of the wave. It has also been shown that in the ultrarelativistic limit (extremely high temperatures) all signal speeds remain less than the speed of light in vacuo.The major part of this article was presented at the Seminar on Natural Philosophy at The Johns Hopkins University, Baltimore, on November 24, 1971. 相似文献
15.
In this paper, we investigate the peristaltic transport of a couple stress fluid in a channel with compliant walls. Perturbation
method has been used to get the solution. The flow is induced by sinusoidal traveling waves along the channel walls. The effects
of wall damping, wall elastance, wall tension and couple stress parameter on the flow are investigated using the equations
of fluid as well as deformable boundaries. It is found that the mean velocity at boundaries decreases with increasing couple-stress
parameter and wall damping and increases with increasing wall tension and wall elastance, while the mean axial velocity increases
with increasing wall tension and wall elastance and decreases with couple-stress parameter and wall damping. 相似文献
16.
The influence of temperature‐dependent viscosity and magnetic field on the peristaltic flow of an incompressible, viscous Newtonian fluid is investigated. The governing equations are derived under the assumptions of long wavelength approximation. A regular perturbation expansion method is used to obtain the analytical solutions for the velocity and temperature fields. The expressions for the pressure rise, friction force and the relation between the flow rate and pressure gradient are obtain. In addition to analytical solutions, numerical results are also computed and compared with the analytical results with good agreement. The results are plotted for different values of variable viscosity parameter β, Hartmann number M, and amplitude ratio ?. It is found that the pressure rise decreases as the viscosity parameter β increases and it increases as the Hartmann number M increases. Finally, the maximum pressure rise (σ=0) increases as M increases and β decreases. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
17.
Zhihua Xie 《国际流体数值方法杂志》2012,70(2):246-268
A two‐phase flow model, which solves the flow in the air and water simultaneously, is presented for modelling breaking waves in deep and shallow water, including wave pre‐breaking, overturning and post‐breaking processes. The model is based on the Reynolds‐averaged Navier–Stokes equations with the k ?ε turbulence model. The governing equations are solved by the finite volume method in a Cartesian staggered grid and the partial cell treatment is implemented to deal with complex geometries. The SIMPLE algorithm is utilised for the pressure‐velocity coupling and the air‐water interface is modelled by the interface capturing method via a high resolution volume of fluid scheme. The numerical model is validated by simulating overturning waves on a sloping beach and over a reef, and deep‐water breaking waves in a periodic domain, in which good agreement between numerical results and available experimental measurements for the water surface profiles during wave overturning is obtained. The overturning jet, air entrainment and splash‐up during wave breaking have been captured by the two‐phase flow model, which demonstrates the capability of the model to simulate free surface flow and wave breaking problems.Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
18.
Accuracy of out-of-plane vorticity measurements derived from in-plane velocity field data 总被引:2,自引:0,他引:2
A study of the errors in out-of-plane vorticity (ω
z
) calculated using a local χ2 fitting of the measured velocity field and analytic differentiation has been carried out. The primary factors of spatial
velocity sampling separation and random velocity measurement error have been investigated. In principle the ω
z
error can be decomposed into a bias error contribution and a random error contribution. Theoretical expressions for the transmission
of the random velocity error into the random vorticity error have been derived. The velocity and vorticity field of the Oseen
vortex has been used as a typical vortex structure in this study. Data of different quality, ranging from exact velocity vectors
of analytically defined flow fields (Oseen vortex flow) sampled at discrete locations to computer generated digital image
frames analysed using cross-correlation DPIV, have been investigated in this study. This data has been used to provide support
for the theoretical random error results, to isolate the different sources of error and to determine their effect on ω
z
measurements. A method for estimating in-situ the velocity random error is presented. This estimate coupled with the theoretically derived random error transmission results
for the χ2 vorticity calculation method can be used a priori to estimate the magnitude of the random error in ω
z
. This random error is independent of a particular flow field. The velocity sampling separation is found to have a profound
effect on the precise determination of ω
z
by introducing a bias error. This bias error results in an underestimation of the peak vorticity. Simple equations, which
are based on a local model of the Oseen vortex around the peak vorticity region, allowing the prediction of the ω
z
bias error for the χ2 vorticity calculation method, are presented. An important conclusion of this study is that the random error transmission
factor and the bias error cannot be minimised simultaneously. Both depend on the velocity sampling separation, but with opposing
effects. The application of the random and bias vorticity error predictions are illustrated by application to experimental
velocity data determined using cross-correlation DPIV (CCDPIV) analysis of digital images of a laminar vortex ring.
Received: 31 October 1997/Accepted: 6 February 1998 相似文献
19.
J. A. Sparenberg 《Applied Scientific Research》1965,14(1):332-338
Summary Linear equations have been derived which approximately describe the motion of a mixture consisting of N components. In each point of the domain of flow N velocity vectors, one for each component, have been assumed. It is shown that these velocity fields can be described by N potential functions. An application is given by considering a sound wave passing through a water-air bubble mixture. 相似文献
20.
G. Radhakrishnamacharya 《Rheologica Acta》1982,21(1):30-35
Peristaltic motion of a power law fluid in a two-dimensional channel is studied. Assuming that the wavelength of the peristaltic wave is large in comparison to the mean half-width of the channel, a solution for the stream function is obtained as an asymptotic expansion in terms of slope parameter. Expressions for axial pressure gradient and shear stress are derived. The effect of flow behaviour indexn on the streamline pattern and shear stress is studied and the phenomenon of trapping is discussed. 相似文献