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Travelling waves solution for MHD aligned flow of a second grade fluid with heat transfer: A symmetry independent approach
*Corresponding author. Tel.: +92 2135040516 njbalam@yahoo.com (Najeeb Alam Khan),
-
Received: ,
Accepted: ,
This article was originally published by Elsevier and was migrated to Scientific Scholar after the change of Publisher.
Available online 6 September 2010
Abstract
In this work, an approach is implemented for finding exact solutions of an incompressible MHD aligned flow with heat transfer in a second grade fluid. This approach based on travelling wave phenomenon. The partial differential equations (PDEs) are reduced to ordinary differential equations (ODEs) by using wave parameter. The methodology used in this work is independent of perturbation, symmetry consideration and other restrictive assumption. Comparison is made with the results obtained previously.
Keywords
Travelling waves
Heat transfer
Second grade fluid
Aligned flows
Introduction
It is an established fact that the flow characteristics of non-Newtonian fluids are quite different when compared with the viscous fluids. Therefore, the well-known Navier–Stokes equations (Berker, 1963; Chandna et al., 1982; Chandna and Oku-Ukpong, 1994a; Hui, 1987; Naeem and Jamil, 2006) are inappropriate for the non-Newtonion fluids. There are numerous models of fluids are mainly classified in the literature. The flows of non-Newtonion fluids (Khan et al., 2009; Fetecau et al., 2008; Fetecau et al., 2006) are mainly classified into differential, integral and rate type fluids. Amongst these, the flows of differential type fluids have attracted the mathematician, computer programmers and numerical solvers. The constitutive equations of differential type fluids are very complex. Several authors in fluid dynamics are engaged with equations of motion of second grade fluid (Hayat et al., 2005; Siddiqui et al., 1985; Labropulu, 2003; Siddiqui, 1990; Rajagopal, 1980; Rajagopal and Gupta, 1984; Kaloni and Huschilt, 1984; Siddiqui and Kaloni, 1986; Mohyuddin et al., 2005; Ali and Hasan, 2007; Ali et al., 2007).
Ting (1963) has studied unsteady flows of a second grade fluid in a bounded region. He studied that the solution exists only if the coefficient of the higher order derivative in the governing equation positive. In 1994, Chandna and Oku-Ukpong (Chandna and Oku-Ukpong, 1994b) studied MHD aligned flow of a second grade fluid by assuming the prescribed form of vorticity. By taking the vorticity to be proportional to the stream function perturbed by a uniform stream, Lin and Tobak (Lin and Tobak, 1986), Benharbit and Siddiqui (Benharbit and Siddiqui, 1992), Labropulu (Labropulu, 2000), they investigated the exact solutions for second grade fluid. Under the slow motion assumption Dolapçi and Pakdemirli (Dolapçi and Pakdemirli, 2004) found the exact solution by Lie group method. Yürüsoy (Yürüsoy, 2004) found exact solutions of steady creeping flow of a second grade fluid with heat transfer via Lie group. Recently, for creeping flow Afify (Afify, 2009) studied the Lie group analysis approach and found the exact solutions for steady MHD aligned second grade fluid with heat transfer.
In this work, the MHD aligned unsteady flow of a second grade fluid with heat transfer is studied. The study of flow for an electrically conducting fluid has applications in many engineering problems such as MHD generators, plasma studied, geothermal energy extractions and electromagnetic propulsion. The electromagnetic propulsion system is closely associated with magneto chemistry, requires a complete understanding of the equation of state and transport properties such as diffusion, stress–shear rate relationship, thermal conductivity and radiation. The investigations of the travelling wave solution of nonlinear equations play an important role in the study of nonlinear physical phenomena. Travelling wave phenomenon, that appears in many areas such as physics (El-Wakil and Abdou, 2008; Yildirim and Gülkanat, 2010), mathematical biology (Mohyud-Din et al., 2010), chemical kinetics, fiber optics, fluid mechanics, etc.
To the best of our knowledge only few studies, which deal with the flows of MHD aligned second grade fluid available in the literature. For the present paper, the method adopted is as follows. In Section 2, we put forward the statement of the problem. A theoretical development of Section 3 is illustrated by solution of the equations of motion of MHD aligned second grade fluid with heat transfer in Section 4. Section 5 synthesis the concluding remarks.
Flow development
The equations of motion of an unsteady MHD aligned flow of a second grade fluid with heat transfer is governed by
If an incompressible fluid of second grade is to have motions that are compatible with thermodynamics in the sense of the Clausius–Duhem inequality and the condition that the Helmholtz free energy be a minimum when the fluid is at rest, then the following must be satisfied (Dunn and Fosdick, 1974)
Travelling waves
Let Lx be a linear form of the independent variables.
A solution
is called an r-multiple travelling wave, if it has the representation
Solution
Without loss of generality one can assume that the travelling wave type solution has the representation
On substituting the representation of the solution (20) into (10)–(14), we have
On integrating the Eqs. (21) and (24), we have
On utilizing Eqs. (27) and (28) in Eqs. (21), (22), (25) and (26), we have
From Eq. (31), the components of magnetic field are
Concluding remarks
The goal to obtain exact solution of an incompressible MHD aligned flow with heat transfer of a second grade fluid. The methodology (Meleshko, 2004) used in this work is easy for linearizing the flow equations by considering travelling wave phenomenon. The method was used in a direct way without transformation, symmetry consideration and restrictive assumptions. It is observed that exponential type solution have been obtained. Finally, compared the velocity and magnetic field in our work by Ali and Mahmood (Ali and Mahmood, 2005) the results are found to be excellent. This guarantees the correctness of the mathematical calculation.
Acknowledgement
The author M. Jamil highly thankful and grateful to the Abdus Salam School of Mathematical Sciences, GC University, Lahore, Pakistan; Department of Mathematics, NED University of Engineering & Technology, Karachi-75270, Pakistan and also Higher Education Commission of Pakistan for supporting and facilitating this research work.
References
- Some new exact solutions for MHD aligned creeping flow and heat transfer in second-grade fluid by using Lie group analysis. Nonlinear Analysis: Theory, Methods and Applications. 2009;70(9):3298-3306.
- [Google Scholar]
- Symmetry reduction of unsteady MHD aligned second grade flow equations. Mathematical and Computational Applications. 2005;10(3):395-402.
- [Google Scholar]
- A different approach to exact solutions in non-Newtonian second-grade of creeping fluid. Applied Mathematics and Computation. 2007;191:484-490.
- [Google Scholar]
- Martin’s method applied to steady plane flow of a second grade fluid. International Journal of Applied Mathematics and Mechanics. 2007;3(3):71-81.
- [Google Scholar]
- Certain solutions of the equations of the planar motion of a second grade fluid for steady and unsteady cases. Acta Mechanica. 1992;94:85-96.
- [Google Scholar]
- Intègration des equations du movement d’un fluide visqueux incompressible, Handbuch der physic, Bd VIII/2. Berlin: Springer; 1963. pp. 1–384
- Flows for chosen vorticity functions exact solutions of the Navier–Stokes equations. International Journal of Mathematics and Mathematical Sciences. 1994;17(1):155-164.
- [Google Scholar]
- Rotational plane flows of a viscous fluid. SIAM Journal of Applied Mathematics. 1982;42(6):1323-1336.
- [Google Scholar]
- An approximation theorem for functionals with applications in continuum mechanics. Archive of Rational Mechanics Analysis. 1960;6:355-370.
- [Google Scholar]
- Approximate symmetries of creeping flow equations of a second grade fluids. International Journal of Nonlinear Mechanics. 2004;39:1603-1619.
- [Google Scholar]
- Dunn, J.E., Fosdick, R.L., 1974. Thermodynamic stability and boundedness of fluid complexity 2 and fluids of second grade. Archive of Rational Mechanics Analysis 56, 191–252.
- New exact traveling wave solutions of two non-linear physical models. Nonlinear Analysis: Theory, Methods and Applications. 2008;68:235-245.
- [Google Scholar]
- Starting solutions for the motion of a second grade fluid due to longitudinal and torsional oscillations of a circular cylinder. International Journal of Engineering Sciences. 2006;44:788-796.
- [Google Scholar]
- Some exact solutions for the helical flow of a generalized Oldroyd-B fluid in a circular cylinder. Computer and Mathematics with Applications. 2008;56:3096-3108.
- [Google Scholar]
- Some inverse solutions for unsteanian fluid. Tamsui Oxford Journal of Mathematical Sciences. 2005;2:1-20.
- [Google Scholar]
- Exact solutions of the unsteady Navier–Stokes equation. Journal of Applied Mathematics and Physics. 1987;38:689-702.
- [Google Scholar]
- Semi inverse solutions of a non-Newtonian fluid. International Journal of Nonlinear Mechanics. 1984;19:373-381.
- [Google Scholar]
- Travelling waves solution of a micropolar fluid. International Journal of Nonlinear Science and Numerical Simulation. 2009;10(9):1121-1125.
- [Google Scholar]
- Exact solutions of non-Newtonian fluid flows with prescribed vorticity. Acta Mechanica. 2000;141:11-20.
- [Google Scholar]
- D’ Alembert motions for non-Newtonian second grade fluid. International Journal of Nonlinear Mechanics. 2003;38:1027-1036.
- [Google Scholar]
- Methods for Constructing Exact Solutions of Partial Differential Equations. Springer; 2004.
- On Solutions for non-linear differential equations arising in Newtonian and non-Newtonian fluids. Nonlinear Dynamics. 2005;35:237-262.
- [Google Scholar]
- Analytic solution of Volterra’s population model. Journal of King Saud University Science. 2010;22(4):247-250.
- [Google Scholar]
- On plane study plane flows of an incompressible fluid with variable viscosity. International Journal of Applied Mathematics and Mechanics. 2006;2(3):32-51.
- [Google Scholar]
- On a class of exact solutions to the equations of motion of a second grade fluid. International Journal of Engineering Sciences. 1984;19:373-381.
- [Google Scholar]
- Some more inverse solutions of a non-Newtonian fluid. Mechanics Research Communication. 1990;17:157-163.
- [Google Scholar]
- Certain-inverse solutions of a non-Newtonian fluid. International Journal of Nonlinear Mechanics. 1986;21:459-473.
- [Google Scholar]
- Hodograph transformation methods in non-Newtonion fluids. Journal of Engineering Mathematics. 1985;19:203-216.
- [Google Scholar]
- Certain nonsteady flows of second-order fluids. Archive of Rational Mechanics Analysis. 1963;14(1963):1-26.
- [Google Scholar]
- Analytical approach to fractional Zakharov–Kuznetsov equations by He’s homotopy perturbation method. Communications in Theoretical Physics. 2010;53(6):1005-1010.
- [Google Scholar]
- Similarity solutions for creeping flow and heat transfer of a second grade fluids. International Journal of Nonlinear Mechanics. 2004;39:665-672.
- [Google Scholar]