Application of Heʹʹs Variational Iteration Method for solving the Equation Governing the Unsteady Flow of a Polytropic Gas

In this paper, Heʹs variational iteration method (VIM) is used to obtain the exact solution of the Equation Governing the Un- steady Flow of a Polytropic Gas. This method is based on Lagrange multiplier for identi¯cation of optimal value of parameter in a functional. Using this method creates a sequence which tends to the exact solution of problem. The method is capable of reducing the size of calculation and easily overcomes the di±culty of the Adomian polynomials. The results reveal that Heʹs variational iteration method is very effective for these types of equations.