AM  Vol.4 No.10 , October 2013
Explicit Approximation Solutions and Proof of Convergence of the Space-Time Fractional Advection Dispersion Equations
Abstract: The space-time fractional advection dispersion equations are linear partial pseudo-differential equations with spatial fractional derivatives in time and in space and are used to model transport at the earth surface. The time fractional order is denoted by β∈ and  is devoted to the space fractional order. The time fractional advection dispersion equations describe particle motion with memory in time. Space-fractional advection dispersion equations arise when velocity variations are heavy-tailed and describe particle motion that accounts for variation in the flow field over entire system. In this paper, I focus on finding the precise explicit discrete approximate solutions to these models for some values of  with  ,  while the Cauchy case as  and the classical case as  with  are studied separately. I compare the numerical results of these models for different values of  and  and for some other related changes. The approximate solutions of these models are also discussed as a random walk with or without a memory depending on the value of . Then I prove that the discrete solution in the Fourierlaplace space of theses models converges in distribution to the Fourier-Laplace transform of the corresponding fractional differential equations for all the fractional values of  and .
Cite this paper: Abdel-Rehim, E. (2013) Explicit Approximation Solutions and Proof of Convergence of the Space-Time Fractional Advection Dispersion Equations. Applied Mathematics, 4, 1427-1440. doi: 10.4236/am.2013.410193.

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