Impact of a disk on shallow water

This paper describes the experiments on shallow-water flat-bottom slamming of a circular disk. The dependence of the added mass of a disk on water depth and impact velocity is experimentally evaluated and compared with available theoretical predictions. The pressure time-histories at the bottom of the test tank are analyzed with the help of the wavelet transform technique. The wavelet spectra of the pressure records are shown to provide useful quantitative information on the significant time-scales of the impact phenomena. It is shown that the presence of an air cushion strongly affects the time-scale of impact and the splash-jet shape.