水下航行体非定常垂直空泡长度的计算

带空泡航行体从水下朝水面运动时,空泡将受到重力梯度和空泡记忆效应的耦合影响而呈现出特殊的非定常特点。为了计算有限水深重力场中的空泡长度,文章在Paryshev空泡动力学数学模型(Delay Differential Equations,DDEs方程)基础上,增加了重力影响项;同时为了快速求解上述空泡DDEs方程,对DDEs的数值方法进行了改进,提出了一种效率更高的对延迟时间点进行局部拟合的方法。最后利用新方法求解了带重力影响的空泡DDEs方程,计算结果与试验结果吻合。

Computation of unsteady vertical cavity length of the underwater vehicle

When the underwater cavity vehicle moves towards the water surface,the cavity will present especial unsteady characteristic as a result of the influence of the gravity gradient and the cavity memory effect.Based on the Paryshev cavity dynamics mathematic model(Delay Differential Equations,DDEs model),the gravity influence was added to compute the cavity length in the limited depth water.The numerical method was improved to raise the computation efficiency of the cavity DDEs.The fast part fitting of delay time points was founded in this paper.Finally,the cavity DDEs with gravity influence were solved by the new method.The computation results are in good agreement with the test results.