Wave Instabilities and Breaking

Wave instabilities and breaking.  Free-surface capillaries (images at left), at a Froude number Fr = 0.43, exhibit large spatial variations of instantaneous velocity and concentrations of positive (red) and negative (yellow) vorticity beneath their troughs and crests. An increase to Fr = 0.56 generates a fully-evolved breaker, represented by the instantaneous velocity in the laboratory frame (top image), and a frame moving at one-third the inflow velocity (middle image). Instantaneous vorticity concentrations are evident in the separated mixing-layer formed at the onset of breaking (bottom image). [16,17]