A new definition of the kinematic breaking onset criterion validated with solitary and quasi-regular waves in shallow water

A large body of work has been devoted to the accurate detection and simulation wave breaking in coastal areas. It is a key process for wide range engineering activities environmental issues. This motivated development variety onset criteria, such as kinematic criteria based on maximum value (usually unity) ratio uc/c, horizontal particle velocity at crest uc its phase c, both taken direction propagation. Here, we investigate numerically validity this criterion capturing solitary quasi-regular two-dimensional shallow water waves using Fully Nonlinear Potential Flow (FNPF) model by Grilli Subramanya (1996). With model, propagation up overturning over plane slopes, submerged bar, initially specified exact FNPF waves, simulated. In all cases, break spilling or plunging breakers, initiated formation breaker jet near crest. Results show that location fluid ||u||m free surface closely coincides with where initiated. Based this, new proposed ||u||m/c≃1, which shown be more universal accurately detecting initiation than existing velocity.