  The paper considers the application of two numerical models to simulate the
evolution of steep breaking waves. The first one is a Lagrangian wave model
based on equations of motion of an inviscid fluid in Lagrangian coordinates. A
method for treating spilling breaking is introduced and includes dissipative
suppression of the breaker and correction of crest shape to improve the post
breaking behaviour. The model is used to create a Lagrangian numerical wave
tank, to reproduce experimental results of wave group evolution. The same set
of experiments is modelled using a novel VoF numerical wave tank created using
OpenFOAM. Lagrangian numerical results are validated against experiments and
VoF computations and good agreement is demonstrated. Differences are observed
only for a small region around the breaking crest.
