환기분사장치의 분사면적변화에 따른 초공동 유동 특성에 관한 연구

Cavity is generated by the fluid machine moves very high speed under water, such as propellers, pump impellers, nozzles, injectors, torpedoes. And there are two main ways to generate cavitation. Natural cavitation is a phenomenon using a very high speed of the machine. It creates a bubble of gas to cover an object travelling under water and it reduces the skin friction. It requires a very high speed but right after the launch of the underwater vehicle, such as a torpedo, proceeds at a very slow speed. So the ventilation devices are added to make the cavity bubble cover the vehicle in the initial steps of launch. And the ventilated cavity generation is related to the volume airflow coefficient. This study shows the relationship between the ventilated volume airflow coefficient and the cavity pressure. If the volume airflow coefficient is the same regardless of a change of ventilation area, it represent a very similar cavity pressure and the ventilated cavitation number.