水下回转航行体的云状空化回射流运动特征研究

Characteristics of the re-entry jet in the cloud cavitating flow over a submerged axisymmetric projectile

该文针对典型的细长回转航行体的水下航行过程,基于SHPB(霍普金森压杆)发射系统开展了机理性实验。相应基于单一流体/多相混合模型,结合空化模型及修正的RNG k湍流模式对该问题进行了数值模拟。并在实验与数值模拟结果的基础上,研究了回射流诱导的云状空化不稳定性问题,探讨了该现象中空化非稳态演化的物理机制,分析了空泡末端回射流的产生原因以及它对空泡演化的诱导作用。进一步从压力梯度角度给出了回射流运动的动力学模型和空泡长度的预测表达式,并通过数值结果验证了该模型和公式的有效性。

For the cloud cavitation around slender axisymmetric projectiles, an experimental system and numerical methods were established. Experimental and numerical results were presented on a typical case. It turns out that the simulation results agree fairly well with the experimental results. An analysis of the evolution of cavitating flow is performed and the related physical mechanism of the formation and effect of re-entry jet is discussed. Furthermore, a dynamic model of re-entry jet and a prediction formula of the cavity length are presented and verified by the numerical results.