The grid-based Eulerian methods have dominated the CFD (Computational
Fluid Dynamics) for decades due to its simplicity. The grids not only
used for discretize the simulation domain but also used for the
computation, however, due to the inherent disadvantages of the
grid-based Eulerian method, the free surface flow cannot be simulated
successfully without special numerical techniques. Recently, another
numerical approach has been developed for hydraulic simulation, namely,
the particlebased Lagrangian approach. In this approach, the domain
discretization as well as the simulation procedure differs from
traditional Eulerian approach. gridless methods are typical Lagrangian
based method, the basic simulation elements used to discretize the
simulation domain become particles rather than grids in gridless method,
which leads the capability of the gridless method in simulating free
surface flow.