Numerical study of the behaviors of two ventilated supercavities in periodic gust flow

In the past few years, scholars have shown great interest in supercavity behavior under unsteady gust flow. Based on the study of single cavity, the two ventilated cavities in the unsteady flow generated by the gust generator at different gust amplitude (Ag) and gust frequencies (fg) are numerically simulated. The shape and flow characteristics of two cavities in periodic gust flow are obtained. Generally, the behavior of two cavities under periodic gust flow is consistent with that of single cavity in some aspects. It is found that the reduction of total cavity length is related to the half wavelength and the vertical velocity, and the critical threshold decreases with higher total cavity length. Subsequently, the influence of the frequency and amplitude of the periodic gust flow on the flow field pressure was studied, which showed that the time corresponding to the minimum pressure under different amplitudes and frequencies is inconsistent. Finally, the influence of gust flow on the cavity pressure is illuminated from the perspective of wave motion on the cavity surface, emphasizes that the pressure change in the closure region directly affect the cavity pressure. Based on the theory, we explain the delay of cavity pressure under different length cavity caused by different amplitude, frequencies and interaction modes. •The longer cavity requires a smaller threshold vflow/U∞.•The moment of extreme cavity pressure tends to increase with longer cavity.•The influence of gusts on the cavity pressure is illuminated from the perspective of wave motion on the cavity surface.