轴对称航行体通气云状空化非定常特征研究

Unsteady characteristics of ventilated cloud cavity around symmetrical bodies

物体在水下高速运动时会在局部区域产生低压而引起空化流动。在预期的空化区域通入气体是调节和控制空化流动的重要手段。文章基于水下水平发射装置观察了轴对称航行体通气空化的非定常演化现象并进行了相应的数值模拟,分析了演化过程和机制,探讨了通气量等主要参数的影响规律。研究表明,从边界层衍生的二次涡切断主涡涡面使尾部主涡脱离是空泡脱落的主要原因;此外,随着通气量的增加,空泡长度和厚度有所增加,脱落位置逐步后移。

Based on a SHPB launch system, an underwater launching experiment of symmetrical bodies is performed and unsteady phenomena are observed. Corresponding numerical simulation is carried out through the commercial software Fluent. The results indicate that the main vortex sheet is cut off by the secondary vortex derived from the boundary layer which leads to the cavity shedding. As the volume of ventilated gas increases, the shedding location moves far away from the injection nozzles, and the length and thickness increase.