失事航天器高速入水砰击数值模拟研究

Numerical simulation study on wrecked aircraft slamming into water with high speed

针对失事航天器入水砰击过程中水动力系数求解精度较低的问题,基于流体体积(VOF)多相流模型和自然空化条件建立了复杂结构物高速入水砰击数值模型,模拟圆柱体入水砰击过程,对砰击荷载、阻力系数、速度和加速度变化规律进行预报,并将数值模拟结果与试验结果进行了精度对比,验证了本研究方法的精确性.在此基础上以典型航天器为研究对象,分析砰击速度和航天器密度对其砰击荷载和水动力系数的影响.研究结果表明:航天器残骸的砰击速度和密度对其阻力系数影响较小,阻力系数稳定值约为0.35;航天器残骸的砰击荷载峰值随砰击速度的增加而增加.

Aiming at the problem of low precision solution of hydrodynamic coefficient in the water entry process of wrecked aircraft,based on the volume of fluid(VOF) multiphase flow model and natural cavitation conditions,a numerical model for highspeed water entry of complex structures was established, and the process of cylindrical water entry was simulated. The variation laws of slamming load,resistance coefficient,velocity and acceleration were predicted,and numerical results were compared with experimental results to verify the accuracy.On this basis,taking typical aircraft as research object,the effects of slamming speed and aircraft density on the slamming load and hydrodynamic coefficient were discussed. Research results show that the effects of slamming speed and density of aircraft debris on its resistance coefficient is slight, and the stable value of resistance coefficient is about 0.35,while the peak value of slamming load of aircraft debris increases with the increase of slamming speed.