1. Physics Department, College of Sciences and Humanitarian Studies, Salman Bin Abdulaziz University, Al-Kharj, Saudi Arabia;
2. Theoretical Physics Group, Faculty of Science, Mansoura University, Mansoura, Egypt
Abstract:
The basic set of fluid equations can be reduced to the nonlinear Kortewege-de Vries (KdV) and nonlinear Schrödinger (NLS) equations. The rational solutions for the two equations has been obtained. The exact amplitude of the nonlinear ion-acoustic solitary wave can be obtained directly without resorting to any successive approximation techniques by a direct analysis of the given field equations. The Sagdeev's potential is obtained in terms of ion acoustic velocity by simply solving an algebraic equation. The soliton and double layer solutions are obtained as a small amplitude approximation. A comparison between the exact soliton solution and that obtained from the reductive perturbation theory are also discussed.