In this study, cold model experiments were carried out to investigate the cavity depth. It was found that the existing model prediction deviated from the experimental results at higher gas flow rate. The normalized linear relationship was obtained between the dimensionless characteristic cavity depth (n0/H) and a combined dimensionless parameter of the Froude number (Fr) and the ratio of nozzle diameter to jet height (de/H). Further, the linear law of the slope and the intercept of normalized fitting line with the nozzle diameter were obtained.
