回转体高速入水弹道模型研究

Trajectory Model of High-speed Water Entry of the Body of Revolution

目的 快速预测回转体高速入水过程中的空泡形态发展和分析回转体高速入水后的弹道特性。方法 基于空泡截面独立扩张原理,建立回转体高速入水非定常超空泡计算方法,通过高速水动力计算方法,结合回转体动力学方程,实现回转体运动参数的求解。结果 通过与文献试验结果对比,验证了回转体高速入水弹道模型的可靠性。对比试验结果,模型的预测误差在10%以内,可满足回转体高速入水弹道预测需要。利用所建立的弹道模型计算了回转体在高速垂直、倾斜入水2种工况下的空泡形态、运动参数变化。发现回转体高速入水过程中,空泡会影响回转体的运动,回转体速度衰减主要和空化器阻力有关。回转体在受到扰动角速度的影响后,滑行力会改变回转体的姿态角和攻角,并使弹道发生弯曲,但有助于回转体运动的稳定。结论 在入水空泡能完全包裹回转体的情况下,可对回转体进行结构优化,增强回转体尾拍运动中受到的滑行力,提升回转体高速入水运动稳定性。适当减小空化器直径,能降低回转体入水过程中的阻力,并增加射程。

This paper aims to predict rapidly the development of cavitation shape of the body of revolution in the process of high-speed water entry and to analyze the ballistic characteristics of the body of revolution after high-speed water entry. Based on the principle of independent expansion of cavitation section, the calculation method of unsteady supercavitation of the body of revolution water entry at high speed was established. The motion parameters of the body of revolution were solved by high-speed hydrodynamic calculation method combined with the dynamic equation of body of revolution. By comparing with the experimental results in literature, the reliability of the calculation model of high-speed water entry trajectory of body of revolution was verified. Compared with the experimental results, the prediction error of the model is less than 10%, which meets the needs of high-speed water entry trajectory prediction of body of revolution. The changes in cavitation shape and motion parameters of body of revolution under two working conditions of high-speed vertical and inclined water entry were calculated. It was found that in the process of high-speed water entry, cavitation will affect the movement of body of revolution, and the velocity attenuation of body of revolution is mainly related to the resistance of the cavitation. After body of revolution was affected by the disturbance angular velocity, the sliding force will change the pitching angle and angle of attack of body of revolution, and bend the trajectory, but it can help to stabilize the movement of body of revolution. If the water entry cavity can completely wrap the rotating body, the structure of body of revolution can be optimized, and the stability of the high-speed water entry movement of body of revolution can be improved by enhancing the sliding force in the tail beat movement of body of revolution;properly reducing the diameter of the cavitation can reduce the resistance of body of revolution in the process of entering the water and increase the range.