Page 151 - IJOCTA-15-2
P. 151

A. Yoku¸s, H. Durur, M.H. Ekici / IJOCTA, Vol.15, No.2, pp.343-353 (2025)
            is directly related to the wave speed. The x term  where m is the integral constant. Using the bal-
            represents the propagation of the wave vibration,  ancing principle between the highest-order linear
            the (-) sign indicates that the wave is propagating  term and the strongest nonlinear term in equa-
            to the right, and the (+) sign indicates that the  tion (9), n = 4 is obtained. Considering equation
            wave is propagating to the left. 47  We can trans-  (6), the solution of equation (9) may be written
            form this to the following ODE for U (ξ) :        as follows.
                               ′
                                      ′′
                                  2

                        S U, U , U , U , ... = 0.       (5)     U (ξ) = α 0 + α 1 Q (ξ) + α 2 (Q (ξ)) 2
                                                                                                  (10)
                Step 2. For the sake of methodology, we as-                       3            4
                                                                       + α 3 (Q (ξ)) + α 4 (Q (ξ)) ,
            sume that the formal solution of equation (5) is
            as follows
                                     n                        the necessary derivatives of the solution presented
                                    X         q
                       U (ξ) = α 0 +    α q Q(ξ) ,      (6)   in equation (10) are calculated and substituted
                                                              in equation (9), which is a reflection of equation
                                    q=1
                                                              (2). After some mathematical operations the fol-
            here α q , q = {1, ..., n} are real or complex con-
                                                              lowing system can be constructed.
            stants to be calculated by mathematical opera-
            tions, such that at least one of these constants is
            different from zero. Furthermore, Q (ξ) , the ker-
                                                                                     2
                                                                                              2 2
                                                                              2
            nel function of equation (6), is the solution of the  Const :  m + v α 0 − k κα 0 − k α = 0,
                                                                                                0
            following basis equation.                          Q [ξ] :  v α 1 − k κα 1 − k ln [a] α 1 − k ϵ ln [a] 4
                                                                                         4
                                                                                                      6
                                                                                               2
                                                                          2
                                                                                 2
                        ′
                                 2


                      Q (ξ) = Q (ξ) − Q (ξ) ln τ,       (7)                 2
                                                                     α 1 − 2k α 0 α 1 = 0,
            the analytical solution of the equation presented
                                                                   2
                                                                                2
                                                                                                4
                                                                          4
                                                                                                       2 2
                                                                                         6
            by equation (7) is as follows.                     Q[ξ] :   3k ln [a] α 1 + 15k ϵ ln [a] α 1 − k α 1
                                                                         2
                                                                                                2
                                                                                          4
                                                                                                         6
                                                                                2
                                       1                              + v α 2 − k κα 2 − 4k ln [a] α 2 − 16k ϵ
                            Q (ξ) =       ,             (8)
                                                                          4
                                                                                  2
                                    1 ± τ  ξ                          ln [a] α 2 − 2k α 0 α 2 = 0,
            where τ > 0, τ ̸= 1 is a real number.                  3        4    2         6      4
                                                               Q[ξ] :   −2k ln [a] α 1 − 50k ϵ ln [a] α 1
                Step 3. The computation of the positive in-
                                                                                                  4
                                                                                 2
                                                                                            6
                                                                           4
            teger n in equation (6) is based on the homoge-           + 10k ln [a] α 2 + 130k ϵ ln [a] α 2
            neous balance between the nonlinear terms and                  2        2      2
            the highest-order derivatives in equation (5). 44         − 2k α 1 α 2 + v α 3 − k κα 3
                                                                                                4
                                                                                2
                                                                                         6
                                                                          4
                Step 4.      By transposing equation (6)              − 9k ln [a] α 3 − 81k ϵ ln [a] α 3
            into equation (5) with equation (7), we cal-              − 2k α 0 α 3 = 0,
                                                                          2
                                    ′
                                        ′′
            culate all necessary U , U , ... derivatives of
                                                                                                2
                                                                                  4
                                                                   4
                                                                                          4
                                                                           6
            U (ξ).   Consequently, we attain a polynomial      Q[ξ] :   60k ϵ ln [a] α 1 − 6k ln [a] α 2
                 j
            of Q (ξ) , (j = 0, 1, 2, ...).  In this polynomial        − 330k ϵ ln [a] α 2 − k α
                                                                                   4
                                                                                           2 2
                                                                             6
            produced, if we add up all the terms with the                  4     2          6  2  4
                           j
            same powers Q (ξ) and set them equal to zero,             + 21k ln [a] α 3 + 525k ϵ ln [a] α 3
                                                                                    2
                                                                          2
                                                                                           2
            we obtain a system of algebraic equations that            − 2k α 1 α 3 + v α 4 − k κα 4
            can be solved with a computer package program                   4    2          6      4
            to produce the unknown parameters k, v and                − 16k ln [a] α 4 − 256k ϵ ln [a] α 4
                                                                          2
            α q , q = {1, ..., n}. Thus, we attain exact solu-        − 2k α 0 α 4 = 0,
            tions of the equation (2).                             5         6     4          6      4
                                                               Q[ξ] :   −24k ϵ ln [a] α 1 + 336k ϵ ln [a] α 2
            3. Application of Kudryashov method                       − 12k ln [a] α 3 − 1164k ϵ ln [a] α 3
                                                                                                   4
                                                                                 2
                                                                                             6
                                                                           4
                                                                                            2
                                                                           2
                                                                                      4
            In this part, the Kudryashov method will be used          − 2k α 2 α 3 + 36k ln [a] α 4
            as a tool for the analytical solution of equation (2)            6      4       2
                                                                      + 1476k ϵ ln [a] α 4 − 2k α 1 α 4 = 0,
            to better understand it and to lead to important
                                                                   6          6      4          6      4
            discussions in the field of fluid mechanics. equa-  Q[ξ] :  −120k ϵ ln [a] α 2 + 1080k ϵ ln [a] α 3
            tion (4), presented as the wave transformation,              2 2       4     2
                                                                      − k α − 20k ln [a] α 4
                                                                            3
            which plays a significant role in elucidating the
                                                                                     4
                                                                                             2
                                                                              6
            characteristics of nonlinear wave propagation, is         − 3020k ϵ ln [a] α 4 − 2k α 2 α 4 = 0,
            applied to equation (2) and integrated twice, the  Q[ξ] :         6      4          6      4
                                                                   7
            following equation can be formed.                           −360k ϵ ln [a] α 3 + 2640k ϵ ln [a] α 4
                                                                           2
                                                                      − 2k α 3 α 4 = 0,
                                  2
                                       4
                                         ′′
                   2
                         2
                                2
                                              2
                                                                                     4
                                                                                           2 2
                                                                              6
                                                                   8
             m+v U −k κU −k U −k U −k U         (4)  = 0, (9)  Q[ξ] :   −840k ϵ ln [a] α 4 −k α = 0.     (11)
                                                                                             4
                                                           346
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