轴对称超空泡流振动频率特性

Frequency Characteristics of Vibration of Axisymmetric Supercavitation

针对复杂超空泡系统微分方程求解困难的问题,提出了一种研究超空泡稳定性的方法,根据Logvinovich截面独立扩张原理,建立了空泡非定常流动模型,再由气体状态方程,将空泡内气体的体积与空泡内气体的压力建立函数关系,经过理论推导,得出空泡内压力的微振方程。通过对压力微振方程的求解,得到超空泡流的振动频率特性。结果表明,空泡的稳定性与动力学相似参数有关,当把该动力学相似参数控制在一定范围内时,空泡在运动过程中是稳定的,否则空泡的稳定状态就会被打破,使空泡破灭。该方法有助于更好地掌握超空泡技术,为工程实践提供理论支撑。

It is difficult to solve the differential equation of complicated supercavitation system. Aiming at the problem, a method for studying the stability of supercavitating cavity was proposed. According to the Logvinovich independent extension principle, unsteady cavity flow model was established. The function relationship between the gas volume and pressure inside the cavity was built from gas state equation. The micro vibration equation of the pressure inside the cavity was derived from theoretical analysis. Vibration frequency characteristics of supercavitating cavity were obtained by solving the micro vibration equation of pressure inside the cavity. The study shows that the stability of cavity is related to dynamics similarity parameters. When these parameters are controlled in a certain range, cavitation is stable in the process of movement, otherwise the steady state of cavitation will be broken,and the cavity will burst. The proposed approach can help to grasp the supercavitation technique better,and provides theoretical support for the engineering practice.