Properties of the pressure field in highly nonlinear free surface flows with critical jet

In this note we examine fluid violent kinematics in a plunging breaker. The motion is computed the frame of potential flow theory. basically generated by forcing rectangular tank, starting from rest. When sufficient level energy injected fluid, free surface has highly nonlinear behavior, here vicinity main tip crest, sharp corner (cusp) appears along barrel. appearance critical jet described and discussed terms spatial temporal variations pressure field. present case local maximum captured that follows continuous decreasing gradient region positive Gaussian curvature pressure. It also shown that, at before jet, there strong correlation between change sign on one hand radius profile other hand.