Experimental study of air bubbles and turbulence characteristics in the surf zone

A set of laboratory experiments of free‐surface elevation, water velocity, void fraction, and bubble distribution was conducted simultaneously for regular wave breaking on a plane slope. The data were collected by using a measurement array of wave gages, a dual‐tip resistivity void fraction probe, and an acoustic Doppler velocimeter. The measurements were conducted in two different wave flumes to check the scale effects of air entrainment into the water on the wave breaking. The power law scaling of bubble size distribution was measured, and it was found that the bubble size has a power law of d −1.5∼−1.7 independent of the location and water depth. The relationship between void fraction and turbulent intensity shows a linear relationship between the void fraction and turbulent intensity.