الفهرس | Only 14 pages are availabe for public view |
Abstract In this thesis we study some nonlinear models in plasma physics and its applications. We obtained exact solutions for some important equations which describe physical models and we obtained related physical quantities. This thesis consists of an introduction, four chapters, 30 figures and a list of Bibliography at the end of each chapter, together with english and arabic summary. This thesis is organized as follow: Introduction. In this introduction we give quick hint for the importance of Magnetohydrodynamics (MHD) and plasma and its applications. Chapter 1. Which considered as a background for the material used in this thesis it cover the fundamental concepts of known results concerning our objects to make this thesis somewhat self contained. Chapter 2. Arrays of vortices are considered for two-dimensional inviscid flows when the functional relationship between the stream function and the vorticity is in form sine, sinh, exponential and power function. Moreover we extend the Jacobi elliptic function method with symbolic computation to these equations for constructing their interesting Jacobi doubly periodic wave solutions. It is shown that soliton solutions and triangular periodic solutions can be established as the limits of Jacobi doubly periodic wave solutions. Chapter 3. In this chapter, we introduced the extended Jacobian elliptic function expan- sion method to construct the exact periodic solutions of two nonlinear wave equations. The periodic solutions obtained by this method can be reduced to the solitary wave solutions under certain limiting conditions. Chapter 4. In this chapter, we used the generalized tanh and the Jacobi elliptic functions methohds for The Drinfeld-Sokolov (DS) system. A variety of exact travelling wave solutions with compact and noncompact structures are formally derived. The study reveals the power of the two schemes in handling identical systems. |