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A STUDY OF SIMPLIFIED SHALLOW WATER WAVES: ASSESSMENT OF ADOMIAN’S DECOMPOSITION METHOD<br />

FOR THE ANALYTICAL SOLUTION<br />

Mehdi Safari<br />

L u L u 3uL u 3L u L udx L u,<br />

(35)<br />

t<br />

where<br />

xxt<br />

t<br />

3<br />

<br />

<br />

L t<br />

, L x<br />

, L xxt<br />

,<br />

2<br />

t x x<br />

t<br />

x<br />

x<br />

t<br />

x<br />

(36)<br />

The terms u0 ( x,<br />

t),<br />

u1(<br />

x,<br />

t),<br />

u2<br />

( x,<br />

t)<br />

<strong>in</strong> Eq.44, obta<strong>in</strong>ed from<br />

Eqs.41, 42, 43. If we assume c=2 then by draw<strong>in</strong>g 3-D figures of ADM<br />

solutions. In Fig.2 the second model of shallow water wave equation<br />

with the first <strong>in</strong>itial condition (31) of Eq. (2) when c=2 has been shown.<br />

Fig.1. For the first model of shallow water wave equation with the first<br />

<strong>in</strong>itial condition (31) of Eq. (2), ADM result for u ( x,<br />

t)<br />

, when c=2.<br />

If the <strong>in</strong>vertible operator<br />

L L u L<br />

1<br />

t<br />

t<br />

1<br />

t<br />

( L<br />

xxt<br />

L<br />

1<br />

t<br />

t<br />

dt<br />

u 3uL u 3L u<br />

t<br />

0<br />

x<br />

is applied to Eq. 45, then<br />

<br />

x<br />

L udx L u),<br />

t<br />

x<br />

(37)<br />

is obta<strong>in</strong>ed. By this<br />

u(<br />

x,<br />

t)<br />

u(<br />

x,0)<br />

L<br />

1<br />

t<br />

( L<br />

xxt<br />

u 3uL u 3L u<br />

t<br />

x<br />

<br />

x<br />

L udx L u),<br />

t<br />

x<br />

(38)<br />

is found. Here the ma<strong>in</strong> po<strong>in</strong>t is that the solution of the decomposition<br />

method is <strong>in</strong> the <strong>form</strong> of<br />

u ( x,<br />

t)<br />

un<br />

( x,<br />

t)<br />

, (39)<br />

n0<br />

Substitut<strong>in</strong>g from Eq. 49 <strong>in</strong> 48, we f<strong>in</strong>d<br />

Fig.2. For the second model of shallow water wave equation with the<br />

first <strong>in</strong>itial condition (31) of Eq. (3), ADM result for u ( x,<br />

t)<br />

, when<br />

c=2.<br />

<br />

<br />

n0<br />

<br />

<br />

<br />

<br />

L ( , ) 3 ( , ) ( , )<br />

1<br />

0<br />

0<br />

0<br />

( , ) ( ,0)<br />

<br />

<br />

<br />

xxtun<br />

x t un<br />

x t Lt<br />

un<br />

x t <br />

n<br />

n<br />

n<br />

<br />

u<br />

n<br />

x t u x Lt<br />

<br />

, (40)<br />

<br />

x<br />

<br />

<br />

<br />

3 ( , ) ( , )<br />

( , ) <br />

Lx<br />

un<br />

x t <br />

Lt<br />

un<br />

x t dx<br />

Lx<br />

un<br />

x t <br />

n0<br />

n0<br />

n0<br />

<br />

is found.<br />

Accord<strong>in</strong>g to Eq.19 approximate solution can be obta<strong>in</strong>ed as follows:<br />

<br />

2 1 c 1<br />

<br />

( c 1)sech<br />

x<br />

2 c<br />

u0<br />

( x,<br />

t)<br />

<br />

<br />

,<br />

2c<br />

1 c 1<br />

c 1<br />

( c 1)s<strong>in</strong>h<br />

<br />

x<br />

2<br />

t<br />

1(<br />

, )<br />

c c<br />

x t <br />

,<br />

<br />

3 1 c 1<br />

<br />

2ccosh<br />

<br />

x<br />

2<br />

c <br />

(41)<br />

u (42)<br />

t<br />

<br />

(43)<br />

u2( x,<br />

t)<br />

( Lxxtu1<br />

3u1L tu1<br />

3Lxu1<br />

Lt<br />

u1dx<br />

Lxu1<br />

) dt,<br />

0<br />

Thus the approximate solution for second model of shallow water wave<br />

equation is obta<strong>in</strong>ed as<br />

u( x,<br />

t)<br />

u0 ( x,<br />

t)<br />

u1(<br />

x,<br />

t)<br />

u2<br />

( x,<br />

t)<br />

, (44)<br />

x<br />

CONCLUSION<br />

In this paper, Adomian’s decomposition method has been successfully<br />

applied to f<strong>in</strong>d the solution of two model equations for shallow water<br />

waves. The obta<strong>in</strong>ed results were showed graphically it is proved that<br />

Adomian's decomposition method is a powerful method for solv<strong>in</strong>g<br />

these equations. In our work; we used the Maple Package to calculate<br />

the functions obta<strong>in</strong>ed from the Adomian’s decomposition method.<br />

<strong>Academy</strong><strong>Publish</strong>.org – Journal of Eng<strong>in</strong>eer<strong>in</strong>g and Technology Vol.2, No.2 19

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