“…In 1992, the professor, Shijun Liao, put forward the homotopy analysis method [1], which is different from the traditional analytic method. Homotopy analysis method provides a simple way to solve convergence region and convergence speed of series solution about the nonlinear problem [2]. We can freely choose different primary functions to express the solution of nonlinear problems to great extent, and it contains some traditional methods in the logical aspect, such as Adomian decomposition method, Lyapunov artificial small parameter method andδ expansion method.…”