EFFECT OF MAGNETIC FIELD ON THE PERISTALTIC TRANSPORT OF COUPLE STRESS FLUID IN A CHANNEL WITH WALL PROPERTIES

2011 ◽  
Vol 04 (03) ◽  
pp. 365-378 ◽  
Author(s):  
G. C. SANKAD ◽  
G. RADHAKRISHNAMACHARYA

Peristaltic transport of an incompressible couple stress fluid in a two-dimensional uniform channel with wall effects and in the presence of magnetic field has been studied. Using long wavelength approximation with low Reynolds number and dynamic boundary conditions, analytical expressions have been derived for velocity and stream function and the effects of pertinent parameters on these flow variables have been studied. The numerical results show that the time average velocity decreases with viscous damping force. Further, it has been observed that trapping occurs and the size of the trapped bolus decreases with Hartman number.

2020 ◽  
Vol 24 (2 Part B) ◽  
pp. 1407-1422
Author(s):  
Safia Akram ◽  
Farkhanda Afzal ◽  
Qamar Afzal

The present article deals with the effects of nanoparticles and magnetic field on the peristaltic flow of a couple stress fluid in an asymmetric channel with different wave forms. Mathematical modelling for 2-D and two directional flows of a couple stress fluid along with nanofluid are first given and then simplified under the assumptions of long wavelength and low Reynolds number approximation. After invoking these approximations we get coupled non-linear differential equations. The exact solutions of temperature distribution, the nanoparticle concentration, velocity, stream function and pressure gradient are calculated. Finally graphical results of various physical parameters of interest are discussed to examine the behavior of flow quantities.


Author(s):  
Liqaa Zeki Hummady ◽  
Iraq T. Abbas ◽  
Rana A. Mohammed

The present study analyzes the effect of couple stress fluid (CSF) with the activity of connected inclined magnetic field (IMF) of a non-uniform channel (NUC) through a porous medium (PM), taking into account the sliding speed effect on channel walls and the effect of nonlinear particle size, applying long wavelength and low Reynolds count estimates. The mathematical expressions of axial velocity, stream function, mechanical effect and increase in pressure have been analytically determined. The effect of the physical parameter is included in the present model in the computational results. The results of this algorithm have been presented in chart form by applying the mathematical program.


2016 ◽  
Vol 38 (1) ◽  
pp. 55-63
Author(s):  
Chander Bhan Mehta

Abstract The study is aimed at analysing thermal convection in a compressible couple stress fluid in a porous medium in the presence of rotation and magnetic field. After linearizing the relevant equations, the perturbation equations are analysed in terms of normal modes. A dispersion relation governing the effects of rotation, magnetic field, couple stress parameter and medium permeability have been examined. For a stationary convection, the rotation postpones the onset of convection in a couple stress fluid heated from below in a porous medium in the presence of a magnetic field. Whereas, the magnetic field and couple stress postpones and hastens the onset of convection in the presence of rotation and the medium permeability hastens and postpones the onset of convection with conditions on Taylor number. Further the oscillatory modes are introduced due to the presence of rotation and the magnetic field which were non-existent in their absence, and hence the principle of exchange stands valid. The sufficient conditions for nonexistence of over stability are also obtained.


2011 ◽  
Vol 66 (5) ◽  
pp. 304-310 ◽  
Author(s):  
Pardeep Kumar ◽  
Hari Mohan

The double-diffusive convection in a compressible couple-stress fluid layer heated and soluted from below through porous medium is considered in the presence of a uniform vertical magnetic field. Following the linearized stability theory and normal mode analysis, the dispersion relation is obtained. For stationary convection, the compressibility, stable solute gradient, magnetic field, and couple-stress postpone the onset of convection whereas medium permeability hastens the onset of convection. Graphs have been plotted by giving numerical values to the parameters to depict the stability characteristics. The stable solute gradient and magnetic field introduce oscillatory modes in the system, which were non-existent in their absence. A condition for the system to be stable is obtained by using the Rayleigh-Ritz inequality. The sufficient conditions for the non-existence of overstability are also obtained.


2018 ◽  
Vol 388 ◽  
pp. 328-343
Author(s):  
R. Suresh Babu ◽  
B. Rushi Kumar ◽  
P.A. Dinesh

A numerical computation has been carriedout for the steady, mixed convective, incompressible, viscous, electrically conducting couple stress fluid through a vertical plate with variable fluid properties in a porous medium. A uniform magnetic field is applied in the transverse direction and parallel to the vertical plate of the physical model and governing equations are derived for it."Using a suitable similarity transformation, governed PDE's are transformed into a set of ODE's which are highly non-linear coupled equations. An advanced Shooting technique is adopted to compute the variations of velocity, temperature, concentration in terms of non-dimensional parameters. Also physical interpretation of non-dimensional parameters like couple stress parameter magnetic field Prandtl number Schmidt number thermal conductivity and solutal diffusivity parameters are examined through plots for both variable permeability and uniform permeability."From the numerical results, an excellent agreement has been observed for the present results, as well as comparison is made between the present and the earlier works for a particular case of the problem.


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