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L.K. Yadav et.al. / IJOCTA, Vol.15, No.1, pp.35-49 (2025)

            Integral transformations undeniably stand out     that the proposed scheme can reduce computa-
            as one of the most beneficial and efficient tech-  tion time and workload compared to other tradi-
            niques in theoretical and applied mathemat-       tional techniques, all while maintaining high ef-
            ics, finding numerous applications in fields such  ficiency. These equations have been previously
            as biology, 9–12  electrodynamics, 13  mechanics, 14  studied and analyzed by various authors using dif-
            biotechnology, 15  chaos theory, 16  and others. 17–20  ferent techniques such as ADM, 34  VIM, 35  coupled
            In recent years, various integral transforms, such  fractional reduced differential transform method
            as Laplace transform, 21,22  Elzaki transform, 23,24  (CFRDTM), 6  Laplace Adomian decomposition
                                                                               1
            Yang integral transform, 25  Aboodh transform 26  method (LADM), optimal homotopy asymptotic
                                                                                                    7
                                                                      4
            Sumudu transform  27  etc. have been employed for  method, Residual power series method, New it-
            solving different physical models.                erative method 36  and other approaches. 37,38
                                                              2. Definitions
            The WBK equations describe the propagation of
            shallow water waves 28  and exhibit different dis-  In this section, some important definitions re-
            persion relations. The coupled scheme of these    lated to the fractional Caputo derivative and the
            equations was developed by Whitham,  29  Broer, 30  Shehu transform are provided to facilitate an un-
            and Kaup.  31  The time fractional coupled WBK    derstanding of the subsequent results.
            equations, incorporating the fractional order Ca-
            puto derivative, exhibit the following structure  Definition 1. The fractional derivative of ϑ ∈
                                                              C m  in Caputo 30,39  sense is defined as
                                                                −1

               C   δ                                           C   δ
                D ξ ϑ + ϑ ϑ µ + ω µ + b ϑ µµ = 0,                D ϑ (µ, ξ)
                   δ
               C D ξ ω + (ωϑ) + a ϑ µµµ − b ω µµ = 0,   (1)       τ
                                                                      m
                              µ                                     ∂ ϑ(µ,ξ)
               where 0 < δ ≤ 1 .                                      ∂ξ m  ,     δ = m ∈ ℵ,
                                                                  
                                                                  
                                                                            ξ
                                                                  
                                                                                            m
                                                                =       1   R  (ξ − υ) m−1−δ ∂ ϑ(χ,υ) dυ,
                                                                   Γ(m−δ)                  ∂υ m
            In equation (1), ϑ (µ, ξ) represents the horizon-              0
                                                                  
                                                                                          m − 1 < δ ≤ m
            tal velocity, ω (µ, ξ) denotes the height deviating
                                                                                                          (2)
            from the equilibrium position, and a, b are real
            constants. It is noteworthy that when a = 1 and                                             31,40
                                                              Definition 2. S. Maitama and W. Zaho,
            b = 0, equation (1) transforms into the modi-
                                                              have introduced the Shehu transform (ST) of an
            fied Boussinesq (MB) equations. Similarly, for
                                                              exponential order function ϑ (ξ) over the set of B,
            a = 0 and b = 1/2, equation (1) becomes the
            approximate long wave (ALW) equations. These
                                                                                                        |ξ|
            equations find applications in hydrodynamics for    B ={ϑ (ξ) : ∃ P 1 , ς 1 , ς 2 > 0, |ϑ (ξ)| < P 1 e  ς j  ,
            illustrating wave propagation in dissipative and                    j
            nonlinear media. They are particularly useful for        if ξ ∈ (−1) × [0, ∞) },
            addressing problems related to water leakage in
            porous subsurface strata and are widely employed  by the integral
            in ocean and coastal engineering.
            In this study, we applied the HASTM with the                                 ∞
            Caputo derivative to analyze applications of equa-                          Z        −sτ
                                                                    S [ϑ (ξ)] = V (s, v) =  ϑ (ξ) e  v dξ,
            tion (1). The key advantage of employing a frac-
            tional derivative model lies in its ability to ac-                          0
            count for memory, history, or non-local effects:        s > 0, τ > 0 ,                        (3)
            a capability challenging to achieve with integer-
            order derivatives. The proposed scheme, namely
                                                              here, V (s, v) is ST of ϑ (ξ).
            HASTM, represents an elegant amalgamation of
            the homotopy analysis method (HAM) and the        Definition 3. (Shehu transform for nth
            Shehu transform.    The HAM,  32,33  is grounded  derivatives) The Shehu transformation for nth
            in the construction of a homotopy that contin-    derivatives is defined as
            uously deforms an initial guess approximation to-
            wards the exact solution of the given problem.
                                                                                             s
                                                                h       i   s n         n−1   n−r−1
                                                                                        X
            The HASTM solution introduces an auxiliary pa-    S ϑ (n)  (ξ) =  V (s, v) −             ϑ (r)  (0).
            rameter ℏ, allowing for adjustment and control                  v n         r=0  v
            of the solution’s convergence. It is noteworthy                                               (4)
                                                            36
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