New multiple soliton solutions to the general Burgers–Fisher equation and the Kuramoto–Sivashinsky equation

A generalized tanh function method is used for constructing exact travelling wave solutions of nonlinear partial differential equations in a unified way. The main idea of this method is to take full advantage of the Riccati equation which has more new solutions. More new multiple soliton solutions are obtained for the general Burgers–Fisher equation and the Kuramoto–Sivashinsky equation.