阻塞效应显著的限制水域船舶水压场数值模型构建与应用

Numerical Models for Calculating Ship Hydrodynamic Pressure Field in Restricted Waters with Significant Blocking Effect

水压水雷依靠船体航行引起的水压场信号而工作,其在浅水、近海等限制水域布防威胁更大。为准确预报限制水域船舶水压场特性,基于黏流理论构建船舶水压场计算流体动力学数值模型,对船舶航行于极窄矩形、阶梯航道等限制水域产生的升沉纵倾、兴波、阻力及水压场等进行计算,并与文献[9]对比分析;基于势流理论构建船舶水压场有限差分数值模型,对比分析两种数值模型的船舶水压纵向曲线,两种数值模型的理论方法虽不同,但结果较为吻合,均可适用于阻塞效应显著或存在混合流动的限制水域,可为更多限制水域船舶水压场特性预报提供技术支撑。研究结果表明:阻塞效应越显著,对计算域网格划分质量要求越高,越需要对水底、岸壁等边界进行均匀加密过渡处理,并设置小时间步长;阻塞效应越显著的限制水域对船体航行姿态影响越大,从而影响船舶水压场特性,使得负压峰值等改变较大,若不能准确预报,则可能导致水雷引信参数设计不合理,战机延误。

Pressure mine works on the signal from ship hydrodynamic pressure field,which is more dangerous in shallow and offshore waters and so on.For obtaining the signals from ship hydrodynamic pressure fields in different restricted waters,a CFD numerical model is proposed based on the viscous theory,and the hydrodynamic characteristics,such as sinkage,trim,wave making and resistance,are calculated and validated.And a finite difference numerical model is established based on the potential flow theory,and the ship hydrodynamic pressure fields calculated by the two numerical models are compared.It is found that the two numerical models are different,but their calculated results are consistent,and they are both suitable for restricted waters with significant blocking effect or mixed flow.The results show that the more obvious the blocking effect is,the higher the grid division quality is,with giving small time step and setting denser grids near the water bottom and shore boundaries.If the blocking effect is more obvious,the restricted water has more significant effect on the hydrodynamic pressure field,and its negative pressure peak changes greatly,which may lead to the unreasonable design of mine fuze parameters,and miss the best detonation time.