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1
Content available Radiative Falkner-Skan flow of Walter-B fluid with prescribed surface heat flux
Hayat T., Qayyum S., Imtiaz M., Alsaedi A.
Journal of Theoretical and Applied Mechanics
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2017
|
Vol. 55 nr 1
117--127
EN
This article addresses the Falkner-Skan flow of an incompressible Walter-B fluid. Fluid flow is caused by a stretching wedge with thermal radiation and prescribed surface heat flux. Appropriate transformations are used to obtain the system of nonlinear ordinary differen- tial equations. Convergent series solutions are obtained by the homotopy analysis method. Influence of pertinent parameters on the velocity, temperature and Nusselt number are in- vestigated. It is observed that by increasing the viscoelastic parameter, the fluid velocity decreases. There is an enhancement of the heat transfer rate for the viscoelastic parameter and power law index. It is also found that the Prandtl number and radiation parameter decrease the heat transfer rate.
2
Content available MHD stagnation point flow of micro nanofluid towards a shrinking sheet with convective and zero mass flux conditions
Rauf A., Shehzad S. A., Hayat T., Meraj M. A., Alsaedi A.
Bulletin of the Polish Academy of Sciences. Technical Sciences
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2017
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Vol. 65, nr 2
155--162
EN
In this article the stagnation point flow of electrically conducting micro nanofluid towards a shrinking sheet, considering a chemical reaction of first order is investigated. Involvement of magnetic field occurs in the momentum equation, whereas the energy and concentrations equations incorporated the influence of thermophoresis and Brownian motion. Convective boundary condition on temperature and zero mass flux condition on concentration are implemented. Partial differential equations are converted into the ordinary ones using suitable variables. The numerical technique is utilized to discuss the results for velocity, microrotation, temperature, and concentration fields.
3
Content available Influence of convective heat and mass conditions in MHD flow of nanofluid
Shehzad S. A., Hayat T., Alsaedi A.
Bulletin of the Polish Academy of Sciences. Technical Sciences
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2015
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Vol. 63, nr 2
465--474
EN
This article aims to investigate the two-dimensional magnetohydrodynamic (MHD) boundary layer flow of nanofluid. Convective mass condition is introduced. Analysis has been discussed in the presence of an applied magnetic field. The Brownian motion and thermophoresis effects are incorporated. The arising nonlinear problems are first converted to ordinary differential equations and then series solutions are constructed. Convergence of series solutions is examined through plots and numerical values. Results are plotted and discussed for the temperature and concentration. Numerical computations for skin-friction coefficient, local Nusselt and Sherwood numbers are performed and analyzed. Comparison with the previous limiting case is noted in an excellent agreement.
4
Content available Effects of inclined magnetic field and Joule heating in mixed convective peristaltic transport of non-Newtonian fluids
Abbasi F. M., Hayat T., Alsaedi A.
Bulletin of the Polish Academy of Sciences. Technical Sciences
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2015
|
Vol. 63, nr 2
501--514
EN
This article describes the influence of an inclined magnetic field on the mixed convective peristaltic transport of fluid in an inclined channel. Two types of non-Newtonian fluids are considered. The problem formulation is presented for the Eyring-Prandtl and Sutterby fluids. Viscous dissipation and Joule heating in the heat transfer process are retained. The presence of a heat source in the energy equation is ensured. The resulting problems are solved by the perturbation method. The plots for different parameters of interest are given and discussed. Numerical values of a heat transfer rate are given and analyzed.
5
Content available remote Optical soliton perturbation with log law nonlinearity
Girgis L., Milovic D., Hayat T., Aldossary O. M., Biswas A.
Optica Applicata
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2012
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Vol. 42, nr 3
447-454
EN
This paper studies the perturbation theory of optical solitons with log law nonlinearity. The adiabatic dynamics of the Gausson parameters are determined in the presence of the perturbation terms. The fixed point is also found and finally the numerical simulation is carried out.
6
Content available remote Modelling of flow and heat transfer in a generalized second grade fluid
Hayat T., Ellahi R., Asghar S.
International Journal of Applied Mechanics and Engineering
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2008
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Vol. 13, no 1
101-121
EN
The flow of a second grade fluid past a porous plate has been studied using a modified model of second grade fluid that has shear dependent viscosity and can predict the normal stress difference. The boundary value problem subject to two different sets of boundary conditions is investigated. In the first instance, we consider that the plate is at temperature higher than the fluid. The second case deals with the analysis of an insulated plate. The differential equations governing the flow are solved using the homotopy analysis method (HAM). Expressions for velocity and temperature profiles are plotted and discussed.
7
Content available remote Unsteady MHD flow due to eccentrically rotating porous disk and a third grade fluid at infinity
Hayat T., Nadeem S., Asghar S., Siddiqui A. M.
International Journal of Applied Mechanics and Engineering
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2006
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Vol. 11, no 2
415-419
EN
This study looks the series solution for the flow of a third grade fluid in a rotating frame. The flow is induced by non-coaxial rotations of porous oscillating disk and a fluid at infinity. It is noted that the obtained expressions for velocity components are valid for all values of the frequencies.
8
Content available remote The unsteady Couette flow of a second grade fluid n a layer of porous medium
Hayat T., Khan M., Ayub M., Siddiqui A. M.
Archives of Mechanics
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2005
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Vol. 57, nr 5
405--416
EN
In this work, the two Couette flows of a second grade fluid are discussed in a porous layer when (i) bottom plate moves suddenly (ii) bottom plate oscillates. Laplace transform method is used to determine the analytic solutions. Expressions for the velocities, volume fluxes and frictional forces are constructed.
9
Content available remote Some more inverse solutions for steady flows of a second-grade fluid
Siddiqui A. M., Mohyuddin M. R., Hayat T., Asghar S.
Archives of Mechanics
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2003
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Vol. 55, nr 4
373-387
EN
Inverse solutions of the equations of motion of an incompressible second-grade fluid are obtained by assuming certain forms of the stream function. Expressions for streamlines, velocity components and pressure distributions are given in each case and compared with the known results.
10
Content available remote Non-Newtonian flows over an oscillating plate with variable suction
Hayat T., Abbas Q., Khan M., Siddiqui A. M.
Archives of Mechanics
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2003
|
Vol. 55, nr 4
327-344
EN
The flow of second order fluid due to an oscillating infinite plate in the presence of a transverse magnetic field for two forms of time-depend suction are considered. The analytical solution of the governing boundary value problems are obtained. It is found that an external magnetic field and normal stress coefficient on the flow has opposite effects.
11
Content available remote Fluctuating flow of a third order fluid past an infinite plate with variable suction
Hayat T., Nadeem S., Pudasaini S. P., Asghar S.
Archives of Mechanics
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2003
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Vol. 55, nr 3
305-324
EN
The two-dimensional flow problem of a third order incompressible fluid past an infinite porous plate is discussed when the suction velocity normal to the plate, as well as the the external flow velocity, varies periodically with time. The governing partial differential equation is of third order and nonlinear. Analytic solution is obtained using the series method. Expressions for the velocity and the skin friction have been obtained in a dimensionless form. The results of viscous and second order fluids can be recovered as special cases of this problem. Finally, several graphs are plotted and discussed.
12
Content available remote Scattering near a penetrable finite plane
Hayat T.
Archives of Acoustics
|
2002
|
Vol. 27, no. 1
41-53
EN
Acoustic scattering due to a point source by a penetrable finite plane introducing the Kutta-Joukowski condition is studied. This investigation is important in the sense that point source is regarded as fundamental radiating device. Mathematical problem which is solved is an approximate model for a noise barrier which is not perfectly rigid and therefore transmits sound. Approximate boundary condition depends upon the thickness and material constants which constitute the finite plane. The problem is solved using integral transforms, the Wiener-Hopf technique and asymptotic methods. It is found that the diffracted field is sum of the fields produced by the two edges of the finite plane and an interaction field. It is once again found that the field produced by the Kutta-Joukowski condition will be substantially larger than the field produced in its absence when the source is near the edge. Finally, physical interpretation of the result is discussed.
13
Content available remote Scattering by a slit in an infinite conducting screen.
Hayat T., Ayub M., Farid T.
Optica Applicata
|
2001
|
Vol. 31, nr 3
635-642
EN
Cylindrical wave diffraction by a slit in an infinite, plane, perfectly conducting barrier in a homogeneous biisotropic medium is investigated. The source point is assumed far from the slit so that the incident cylindrical wave is locally plane. The slit is wide and the barrier thin, both with respect to wavelength. The boundary value problem is reduced to a Wiener-Hopf equation and solved approximately
14
Content available remote Diffraction by a perfectly conducting open-ended waveguide in a homogeneous biisotropic medium
Aschar S., Hayat T.
Optica Applicata
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2000
|
Vol. 30, nr 2-3
361-373
EN
In this paper, the diffraction of an electromagnetic wave within perfectly conducting parallel-plates embedded in a homogeneous biisotropic medium is examined. The vector diffraction problem is reduced to the scattering of a single scalar field, the latter being the normal component of either a left-handed or a right-handed Beltrami field. The scattering of the left-handed field component is explicitly analyzed, with that of the other scalar field being analogously tractable.
15
Content available remote Propagation of a low frequency electromagnetic pulse generated by an electric dipole in seawater.
Ayub M., Hayat T., Asghar S.
Optica Applicata
|
1999
|
Vol. 29, nr 4
561-571
EN
An exact analytic solution for the propagation in seawater of low frequency electromagnetic pulse generated by an electric dipole is investigated. The dipole is excited by a rectangular current pulse with a finite, nonzero rise and decay time. The frequency-domain formulas for the downward-travelling field of horizontal electric dipole excited by pulse is Fourier transformed to obtain an explicit expression for the field that is uniformly valid in distance and time. is noted that the present analysis may be used for studying pulse propagation in any highly conductiong medium besides seawater.
16
Content available remote Cylindrical wave diffraction by an absorbing strip
Asghar S., Hayat T.
Archives of Acoustics
|
1998
|
Vol. 23, no. 3
391-402
EN
A solution for the problem of diffraction of a cylindrical sound wave near an absorbing strip introducing the Kutta-Joukowski condition is obtained. The two faces of the strip have impedance boundary conditions. The problem which is solved is a mathematical model for a noise barrier whose surface is treated with acoustically absorbing materials. It is found that the field produced by the Kutta-Joukowski condition will be substantially in excess of that in its absence when the source is near the edge.
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