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Abstract and Applied Analysis

Volume 2014 (2014), Article ID 249071, 9 pages

http://dx.doi.org/10.1155/2014/249071
Research Article

The Jacobi Elliptic Equation Method for Solving Fractional Partial Differential Equations

School of Science, Shandong University of Technology, Zibo, Shandong 255049, China

Received 21 April 2014; Accepted 4 June 2014; Published 24 June 2014

Academic Editor: Tiecheng Xia

Copyright © 2014 Bin Zheng and Qinghua Feng. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Based on a nonlinear fractional complex transformation, the Jacobi elliptic equation method is extended to seek exact solutions for fractional partial differential equations in the sense of the modified Riemann-Liouville derivative. For demonstrating the validity of this method, we apply it to solve the space fractional coupled Konopelchenko-Dubrovsky (KD) equations and the space-time fractional Fokas equation. As a result, some exact solutions for them including the hyperbolic function solutions, trigonometric function solutions, rational function solutions, and Jacobi elliptic function solutions are successfully found.

1. Introduction

In the nonlinear sciences, it is well known that many nonlinear partial differential equations are widely used to describe the complex phenomena in various fields. The powerful and efficient methods to find analytic solutions and numerical solutions of nonlinear equations have drawn a lot of interest by a diverse group of scientists. Many efficient methods have been presented so far (e.g., see [19]). Fractional differential equations are generalizations of classical differential equations of integer order. In recent decades, fractional differential equations have gained much attention as they are widely used to describe various complex phenomena in many fields such as the fluid flow, signal processing, control theory, systems identification, and biology and other areas. Many experts have investigated theoretic problems of fractional differential equations so far, and the concerned fields include the existence and uniqueness of solutions to Cauchy type problems, the methods for explicit and numerical solutions, and the stability of solutions (e.g., see [1015]). Among these investigations for fractional differential equations, research for seeking analytical or semianalytical solutions of fractional differential equations has been paid an increasing attention. Many analytical or semianalytical methods have been proposed to obtain numerical solutions and exact solutions of fractional differential equations so far. For example, these methods include the ( ) method [1618], the variational iterative method [1921], and the fractional subequation method [2226]. Based on these methods, a variety of fractional differential equations have been investigated.

In this paper, we extend the Jacobi elliptic equation method to seek exact solutions for fractional partial differential equations in the sense of modified Riemann-Liouville derivative. Based on a nonlinear fractional complex transformation, certain fractional partial differential equation can be converted into another ordinary differential equation of integer order with respect to one new variable, which can be solved based on the Jacobi elliptic equation. This method belongs to the categories of fractional subequation methods, and with the general solutions of the Jacobi elliptic equation, a series of exact solutions for the fractional partial differential equation can be obtained.

Definition 1. The modified Riemann-Liouville derivative of order is defined by the following expression [2730]:

Definition 2. The Riemann-Liouville fractional integral of order on the interval is defined by

Some important properties for the modified Riemann-Liouville derivative and fractional integral are listed as follows (see [2227]) (the interval concerned below is always defined by ):

The rest of this paper is organized as follows. In Section 2, we give the description of the Jacobi elliptic equation method for solving fractional partial differential equations. Then in Section 3 we apply this method to establish exact solutions for the space fractional coupled Konopelchenko-Dubrovsky (KD) equations and the space-time fractional Fokas equation. Some conclusions are presented at the end of the paper.

2. Description of the Jacobi Elliptic Equation Method for Solving Fractional Partial Differential Equations

In this section we give the description of the Jacobi elliptic equation method for solving fractional partial differential equations.

Suppose that a fractional partial differential equation, say in the independent variables , is given by where , , are unknown functions and is a polynomial in and their various partial derivatives including fractional derivatives.

Step 1. Execute a certain nonlinear fractional complex transformation for : such that (8) can be turned into the following ordinary differential equation of integer order with respect to the variable :

In fact, take ; for example, one can suppose a nonlinear fractional complex transformation , and then by using (3) obtain .

Step 2. Suppose that the solution of (10) can be expressed by a polynomial in as follows: where , , , are constants to be determined later, , the positive integer can be determined by considering the homogeneous balance between the highest order derivatives and nonlinear terms appearing in (10), and satisfies the following Jacobi elliptic equation [31]: where , , and are arbitrary constants.

Some general solutions of (12) are listed as follows: where is a constant, , , and denote the Jacobi elliptic sine function, Jacobi elliptic cosine function, and the Jacobi elliptic function of the third kind, respectively, is the modulus, and Furthermore, one has Other solutions with , , and taking different values are omitted here for the sake of simplicity.

Step 3. Substituting (11) into (10) and using (12), the left-hand side of (10) is converted into another polynomial in . Collecting all coefficients of the same power and equating them to zero yield a set of algebraic equations for , , .

Step 4. Solving the equations’ system in Step 3, and using the general solutions of (12), we can construct a variety of exact solutions for (8).

3. Application of the Jacobi Elliptic Equation Method to Some Fractional Partial Differential Equations

3.1. Space Fractional Coupled Konopelchenko-Dubrovsky (KD) Equations

Consider the space fractional coupled Konopelchenko-Dubrovsky (KD) equations where denotes the modified Riemann-Liouville derivative of order . Equation (16) is a variation of the coupled Konopelchenko-Dubrovsky (KD) equations of integer order [32].

In the following, we will apply the Jacobi elliptic equation method described in Section 2 to solve (16). To begin with, we suppose , , where + , , , , are all constants with . Then by use of (3) and the first equality of (5) we obtain Then (16) can be turned into the following form:

Suppose that the solution of (18) can be expressed by where satisfies (12). Balancing the order of and , and in (18) we have . So,

Substituting (20) into (18), using (12), collecting all the terms with the same power of together, and equating each coefficient to zero yield a set of algebraic equations. Solving these equations yields that

Substituting the result above into (20) and combining with (15) we can obtain the following exact solutions for (16).

Family 1. When , , , the following hyperbolic function solution can be obtained: where .

In Figures 1 and 2, the solitary wave solutions , in (22) with some special parameters are demonstrated.

249071.fig.001
Figure 1: The solitary wave solution with , , , and .
249071.fig.002
Figure 2: The solitary wave solution with , , , and .

Family 2. When , , , where .

Family 3. When , , , the following trigonometric function solution can be obtained: where .

In Figures 3 and 4, the periodic wave solutions , in (24) with some special parameters are demonstrated.

249071.fig.003
Figure 3: The periodic wave solution with , , , and .
249071.fig.004
Figure 4: The periodic wave solution with , , , and .

Family 4. When , , , the following rational function solution can be obtained: where .

Family 5. When , , , the following Jacobi elliptic function solution can be obtained: where .

Family 6. When , , , where .

Family 7. When , , , where .

Family 8. When , , , where .

Family 9. When , , , where .

Family 10. When , , , where .

Remark 3. We note that the exact solutions established in (22)–(31) are new exact solutions to the space fractional coupled Konopelchenko-Dubrovsky (KD) equations.

3.2. Space-Time Fractional Fokas Equation

Consider the space-time fractional Fokas equation [33, 34] In [33, 34], the authors solved (32) by use of the Riccati equation method and a fractional subequation method, respectively. Based on the two methods, some exact solutions for it were obtained. Now we will apply the Jacobi elliptic equation method described in Section 2 to solve (32).

Suppose , where + , , , , , , are all constants with . Then by use of (3) and the first equality in (5), (32) can be turned into the following form:

Suppose that the solution of (33) can be expressed by where satisfies (12). By balancing the order between the highest order derivative term and nonlinear term in (33), we can obtain . So we have

Substituting (35) into (33), using (12), collecting all the terms with the same power of together, and equating each coefficient to zero yield a set of algebraic equations. Solving these equations yields that

Substituting the result above into (35) and combining with (15) we can obtain the following exact solutions to (32).

Family 1. When , , , where .

Family 2. When , , , where .

Family 3. When , , , where .

Family 4. When , , , where .

Family 5. When , , , where .

Family 6. When , , , where .

Family 7. When , , , where .

Family 8. When , , , where .

Family 9. When , , , where .

Family 10. When , , , where .

Remark 4. If we put , , then the solutions (37)–(40) reduce to the results established in [33, ]. On the other hand, as a different subequation was used here from that in [34], one can see that our results are essentially different from those in [34]. Furthermore, we note that the Jacobi elliptic function solutions denoted in (41)–(46) are new exact solution to the space-time fractional Fokas equation so far to the best of our knowledge.

4. Conclusions

Based on nonlinear fractional complex transformation, we have extended the Jacobi elliptic equation method to seek exact solutions for fractional partial differential equations in the sense of modified Riemann-Liouville derivative. By use of this method, the space fractional coupled Konopelchenko-Dubrovsky (KD) equations and the space-time fractional Fokas equation are solved successfully. With the aid of the mathematical software, a series of exact solutions including not only hyperbolic function solutions, trigonometric function solutions, and rational function solutions but also Jacobi elliptic function solutions for the two equations have been found. Being concise and powerful, this method can be applied to solve many other fractional partial differential equations.

Conflict of Interests

The authors declare that there is no conflict of interests regarding the publication of this paper.

Acknowledgments

This work was partially supported by the Natural Science Foundation of Shandong Province (in China) (Grant no. ZR2013AQ009), the National Training Programs of Innovation and Entrepreneurship for Undergraduates (Grant no. 201310433031), and the Doctoral Initializing Foundation of Shandong University of Technology (in China) (Grant no. 4041-413030).

References

  1. H. Naher and F. A. Abdullah, “New generalized and improved (G′/G)-expansion method for nonlinear evolution equations in mathematical physics,” Journal of the Egyptian Mathematical Society, 2013. View at Publisher · View at Google Scholar · View at Scopus
  2. S. Borazjani, P. Bedrikovetsky, and R. Farajzadeh, “Exact solution for non-self-similar wave-interaction problem during two-phase four-component flow in porous media,” Abstract and Applied Analysis, vol. 2014, Article ID 731567, 13 pages, 2014. View at Publisher · View at Google Scholar · View at MathSciNet
  3. M. Ali Akbar and N. H. M. Ali, “The modified alternative (G′/G)-expansion method for finding the exact solutions of nonlinear PDEs in mathematical physics,” International Journal of Physical Sciences, vol. 6, no. 35, pp. 7910–7920, 2011. View at Publisher · View at Google Scholar · View at Scopus
  4. E. Zayed and M. Abdelaziz, “Exact traveling wave solutions of nonlinear variable coefficients evolution equations with forced terms using the generalized (G′/G)-expansion method,” WSEAS Transactions on Mathematics, vol. 10, no. 3, pp. 115–124, 2011. View at Zentralblatt MATH · View at Scopus
  5. N. Taghizadeh, M. Mirzazadeh, A. Samiei Paghaleh, and J. Vahidi, “Exact solutions of nonlinear evolution equations by using the modified simple equation method,” Ain Shams Engineering Journal, vol. 3, no. 3, pp. 321–325, 2012. View at Publisher · View at Google Scholar · View at Scopus
  6. M. Wang, X. Li, and J. Zhang, “The (G/G)-expansion method and travelling wave solutions of nonlinear evolution equations in mathematical physics,” Physics Letters: A, vol. 372, no. 4, pp. 417–423, 2008. View at Publisher · View at Google Scholar · View at MathSciNet · View at Scopus
  7. A. Wazwaz, “New solitary wave and periodic wave solutions to the (2+1)-dimensional Nizhnik-NOVikov-Veselov system,” Applied Mathematics and Computation, vol. 187, no. 2, pp. 1584–1591, 2007. View at Publisher · View at Google Scholar · View at MathSciNet · View at Scopus
  8. J. H. He and X. H. Wu, “Exp-function method for nonlinear wave equations,” Chaos, Solitons & Fractals, vol. 30, no. 3, pp. 700–708, 2006. View at Publisher · View at Google Scholar · View at MathSciNet · View at Scopus
  9. M. A. Abdou, “The extended tanh method and its applications for solving nonlinear physical models,” Applied Mathematics and Computation, vol. 190, no. 1, pp. 988–996, 2007. View at Publisher · View at Google Scholar · View at Zentralblatt MATH · View at MathSciNet · View at Scopus
  10. I. Podlubny, Fractional Differential Equations, vol. 198 of Mathematics in Science and Engineering, Academic Press, San Diego, Calif, USA, 1999. View at MathSciNet
  11. J. Sabatier, O. P. Agrawal, and J. A. Machado, Advance in Fractional Calculus: Theoretical Developments and Applications in Physics and Engineering, Springer, Dordrecht, The Netherlands, 2007. View at Publisher · View at Google Scholar · View at MathSciNet
  12. D. Baleanu, B. Guvenc, and J. A. Tenreiro, New Trends in Nanotechnology and Fractional Calculus Applications, Springer, New York, NY, USA, 2010. View at MathSciNet
  13. V. Lakshmikantham, S. Leela, and J. Vasundhara, Theory of Fractional Dynamic Systems, Cambridge Academic Publishers, Cambridge, UK, 2009.
  14. Z. Odibat and S. Momani, “A generalized differential transform method for linear partial differential equations of fractional order,” Applied Mathematics Letters, vol. 21, no. 2, pp. 194–199, 2008. View at Publisher · View at Google Scholar · View at MathSciNet · View at Scopus
  15. J. H. Ma and Y. Q. Liu, “Exact solutions for a generalized nonlinear fractional Fokker-Planck equation,” Nonlinear Analysis: Real World Applications, vol. 11, no. 1, pp. 515–521, 2010. View at Publisher · View at Google Scholar · View at MathSciNet · View at Scopus
  16. N. Shang and B. Zheng, “Exact solutions for three fractional partial differential equations by the (G'/G) method,” IAENG International Journal of Applied Mathematics, vol. 43, no. 3, pp. 114–119, 2013. View at MathSciNet
  17. B. Zheng, “Exact solutions for some fractional partial differential equations by the (G/G) method,” Mathematical Problems in Engineering, vol. 2013, Article ID 826369, 13 pages, 2013. View at Publisher · View at Google Scholar · View at MathSciNet
  18. B. Zheng, “(G/G)-expansion method for solving fractional partial differential equations in the theory of mathematical physics,” Communications in Theoretical Physics, vol. 58, no. 5, pp. 623–630, 2012. View at Publisher · View at Google Scholar · View at MathSciNet · View at Scopus
  19. J. H. He, “A new approach to nonlinear partial differential equations,” Communications in Nonlinear Science and Numerical Simulation, vol. 2, no. 4, pp. 230–235, 1997. View at Publisher · View at Google Scholar · View at Scopus
  20. G. C. Wu, “A fractional variational iteration method for solving fractional nonlinear differential equations,” Computers & Mathematics with Applications, vol. 61, no. 8, pp. 2186–2190, 2011. View at Publisher · View at Google Scholar · View at MathSciNet · View at Scopus
  21. S. Guo and L. Mei, “The fractional variational iteration method using He's polynomials,” Physics Letters A, vol. 375, no. 3, pp. 309–313, 2011. View at Publisher · View at Google Scholar · View at MathSciNet · View at Scopus
  22. S. Zhang and H. Q. Zhang, “Fractional sub-equation method and its applications to nonlinear fractional PDEs,” Physics Letters: A, vol. 375, no. 7, pp. 1069–1073, 2011. View at Publisher · View at Google Scholar · View at MathSciNet · View at Scopus
  23. S. M. Guo, L. Q. Mei, Y. Li, and Y. F. Sun, “The improved fractional sub-equation method and its applications to the space-time fractional differential equations in fluid mechanics,” Physics Letters A, vol. 376, no. 4, pp. 407–411, 2012. View at Publisher · View at Google Scholar · View at MathSciNet · View at Scopus
  24. B. Lu, “Bäcklund transformation of fractional Riccati equation and its applications to nonlinear fractional partial differential equations,” Physics Letters A, vol. 376, no. 28-29, pp. 2045–2048, 2012. View at Publisher · View at Google Scholar · View at MathSciNet · View at Scopus
  25. B. Tang, Y. He, L. Wei, and X. Zhang, “A generalized fractional sub-equation method for fractional differential equations with variable coefficients,” Physics Letters A, vol. 376, no. 38-39, pp. 2588–2590, 2012. View at Publisher · View at Google Scholar · View at MathSciNet · View at Scopus
  26. C. Wen and B. Zheng, “A new fractional sub-equation method for fractional partial differential equations,” WSEAS Transactions on Mathematics, vol. 12, no. 5, pp. 564–571, 2013. View at Scopus
  27. G. Jumarie, “Modified Riemann-Liouville derivative and fractional Taylor series of nondifferentiable functions further results,” Computers & Mathematics with Applications, vol. 51, no. 9-10, pp. 1367–1376, 2006. View at Publisher · View at Google Scholar · View at MathSciNet · View at Scopus
  28. G. Jumarie, “Table of some basic fractional calculus formulae derived from a modified Riemann-Liouville derivative for non-differentiable functions,” Applied Mathematics Letters, vol. 22, no. 3, pp. 378–385, 2009. View at Publisher · View at Google Scholar · View at MathSciNet · View at Scopus
  29. G. Jumarie, “Cauchy's integral formula via the modified Riemann-Liouville derivative for analytic functions of fractional order,” Applied Mathematics Letters, vol. 23, no. 12, pp. 1444–1450, 2010. View at Publisher · View at Google Scholar · View at MathSciNet · View at Scopus
  30. G. Jumarie, “Fractional partial differential equations and modified Riemann-Liouville derivative new methods for solution,” Journal of Applied Mathematics & Computing, vol. 24, no. 1-2, pp. 31–48, 2007. View at Publisher · View at Google Scholar · View at MathSciNet · View at Scopus
  31. E. M. E. Zayed, “New traveling wave solutions for higher dimensional nonlinear evolution equations using a generalized (G′/G)-expansion method,” Journal of Physics A: Mathematical and Theoretical, vol. 42, no. 19, pp. 195202–195214, 2009. View at Publisher · View at Google Scholar · View at MathSciNet · View at Scopus
  32. S. Zhang, “Exp-function method for Riccati equation and new exact solutions with two arbitrary functions of (2+1)-dimensional Konopelchenko-Dubrovsky equations,” Applied Mathematics and Computation, vol. 216, no. 5, pp. 1546–1552, 2010. View at Publisher · View at Google Scholar · View at MathSciNet · View at Scopus
  33. F. Meng, “A new approach for solving fractional partial differential equations,” Journal of Applied Mathematics, vol. 2013, Article ID 256823, 5 pages, 2013. View at Publisher · View at Google Scholar · View at MathSciNet
  34. B. Zheng and C. Wen, “Exact solutions for fractional partial differential equations by a new fractional sub-equation method,” Advances in Difference Equations, vol. 2013, article 199, 12 pages, 2013. View at Publisher · View at Google Scholar · View at MathSciNet