A Method of Mitigating Pulsation in Ventilated Supercavities

A method for mitigating ventilated supercavity pulsation is presented. The method, which has its roots in parametric oscillators, shifts the supercavity resonance frequency by modulating its gas ventilation rate. When appropriately modulated, the supercavity is driven off resonance by the waves on the gas/water interface (that remain unchanged) and pulsation is, therefore, suppressed. Initial experimental results indicate that the gas ventilation rate modulation frequency must be sufficiently different from the supercavity resonance frequency to mitigate pulsation. If the modulation frequency is not sufficiently different from the supercavity resonance frequency, pulsation is simply shifted in frequency with a corresponding small reduction in the supercavity interior pressure spectrum level and radiated noise.