基于流固耦合的固体推进剂药柱裂纹稳定性分析  

Stability analysis on solid propellant grain crack based on fluid-solid coupling interaction

作　　者：蔡子林 高峰[1] 张泽 马岑睿[1] CAI Zilin;GAO Feng;ZHANG Ze;MA Cenrui(Air and Missile Defense College,Air Force Engineering University,Xi’an 710051)

机构地区：[1]空军工程大学防空反导学院,西安710051

出　　处：《固体火箭技术》2022年第6期869-876,共8页Journal of Solid Rocket Technology

摘　　要：含有裂纹缺陷的固体推进剂药柱会严重影响固体火箭发动机的工作性能,甚至带来严重的后果。采用流固耦合计算方法将流场压强信息传递至固体域,为固体域的受力计算提供边界条件。通过对裂纹类型缺陷进行J积分计算,分析J积分值的变化情况,得出影响缺陷发生扩展的因素。以往的研究表明,裂纹区域J积分值越大,裂纹的稳定性也越差。基于此,分析结果表明:裂纹的尺寸对腔内的燃气分布规律有显著的影响,裂纹深度的增加及宽度的减小均会引起裂纹内部燃气压强的升高,裂纹腔内压强越高,越容易导致裂纹发生扩展;裂纹深度的增大以及发动机点火升压速率提高,均会造成裂纹区域J积分值的增加,从而易使裂纹发生扩展;横向裂纹较纵向裂纹J积分值较大,在同等情况下更容易发生拓展;同时,裂纹越靠近药柱后部,受到壳体的约束越弱,导致裂纹尖端J积分值的增大,越容易发生拓展。For the propellant grain with cracks,the existence of cracks will seriously affect the working performance of solid rocket motor,and even lead to serious consequences.In this paper,the fluid-solid coupling method was used to transfer the pressure information of the flow field to the solid domain,which provides boundary conditions for calculation of the force in the solid domain.Through the J-integral calculation of crack defect type,the change of J-integral value was analyzed,and the factors affecting the crack propagation were obtained.Previous studies have shown that the greater the J-integral value is in the crack region,the worse the stability of crack is.At present,it is found that the crack size has a significant effect on the gas distribution in the cavity;both the increase of crack depth and the decrease of crack width lead to the increase of gas pressure inside the crack cavity,which makes it easier for crack to expand.The higher the pressure is inside the crack cavity,the easier the crack propagation become.It is also found that the J-integral value in the crack region increases with the increase of crack depth or the motor ignition pressure boost rate,which make it easier for crack to expand.Under the same situation,when the J-integral value of transverse crack is larger than that of longitudinal crack,the crack propagation is more likely to occur.The closer the crack is to the rear of grain,the weaker the case constraint of crack is,leading to the increase of J-integral value of crack tip,and the crack is easier to expand.

关 键 词：流固耦合计算方法 固体推进剂药柱 奇异界面裂纹单元 三维J积分 

分 类 号：V435.21[航空宇航科学与技术—航空宇航推进理论与工程]