Further improved extended Fan sub-equation method and new exact solutions of the (2 + 1)-dimensional Broer–Kaup–Kupershmidt equations

In this paper, a further improved extended Fan sub-equation method is proposed by taking a more general transformation to seek more types of exact solutions of non-linear partial differential equations. With the aid of symbolic computation, we choose the (2 + 1)-dimensional Broer–Kaup–Kupershmidt equations to illustrate the validity and advantages of this method. As a result, many new and more general non-travelling wave and coefficient function solutions are obtained including soliton-like solutions, triangular-like solutions, single and combined non-degenerate Jacobi elliptic wave function-like solutions, Weierstrass elliptic doubly-like periodic solutions.