水锤效应影响因素及防护结构的数值研究

Numerical Research on Influencing Factors of Hydrodynamics Ram Effect and Protective Structure

燃油箱作为飞机上易损性最高的部件,当其遭受高速射弹袭击时会产生破坏严重的液压水锤效应,直接威胁飞机安全,对水锤效应问题的数值研究具有重要意义。采用CEL方法对水锤效应问题进行数值模拟,首先同已有试验结果进行对比,验证数值计算模型的准确性;然后分析射弹入射速度、充液率对水锤效应的影响;最后对水锤效应的防护设计进行数值分析,优选防护结构设置形式。结果表明:水锤效应的破坏威力来自于冲击波,射弹动能越大、充液率越高,对油箱的破坏性越大;设置防护挡板能够在一定程度上降低冲击波对油箱结构的破坏程度,空气防护挡板结构的防护效果最佳。

As the most vulnerable part of the aircraft,the fuel tank is damaged by hydrodynamics ram effect when attacked by high-speed projectiles,which will directly threaten the safety of the aircraft. The numerical research on the hydrodynamics ram effect is of great significance. In this paper,CEL(coupled Eulerian Lagrangian) method is used to simulate the hydrodynamics ram effect. Firstly,the accuracy of the numerical model is verified by comparing with the existing experimental results;Then,the effects of impact velocity and liquid filling rate on the hydrodynamics ram effect are analyzed. Finally,in order to reduce the damage power of hydrodynamics ram effect,the design of protective structure is numerically analyzed. The results show that the damage power of hydrodynamics ram effect comes from shock wave. The greater the kinetic energy of projectile and the higher the liquid filling rate,the greater the damage of oil tank. The protective baffle can reduce the damage caused by shock wave to the oil tank structure to a certain extent,and the air-interlayer protective structure is the best for the protective effect.