高浓度颗粒流冲刷条件下硅橡胶和EPDM绝热材料动态烧蚀实验

Real-time ablation measurements on erosion of silicone rubber and EPDM material by highly concentrated particles

关键词:  固体火箭发动机  绝热材料  烧蚀  X射线实时诊断技术 

Key words:  Solid rocket motor  Insulation  Ablation  Real-time X-ray radiography technique (RTR)

摘要:

利用X射线实时诊断技术(RTR)针对硅橡胶和EPDM绝热材料,开展了高浓度颗粒流冲刷条件下动态烧蚀实验研究,成功获得了绝热材料烧蚀表面退移过程的序列图像。研究表明:(1)在本实验条件下,硅橡胶绝热材料颗粒冲刷区域的瞬时烧蚀率在0~2s内迅速增加,2s之后瞬时烧蚀率略有下降并趋于稳定；EPDM绝热材料颗粒冲刷区域的瞬时烧蚀率在0~1s内迅速增加,1s之后瞬时烧蚀率趋于稳定；(2)相同冲刷条件下硅橡胶绝热材料抗颗粒流冲刷性能比EPDM绝热材料差,硅橡胶绝热材料不适合在高过载发动机中应用；(3)高浓度颗粒流冲刷条件下绝热材料的烧蚀率比常规条件下要严重的多,其机理主要是高温颗粒流对炭化层有强烈的机械剥蚀效应和热化学烧蚀作用。实验结果对硅橡胶和EPDM绝热材料烧蚀机理研究及烧蚀建模具有重要参考价值。

Abstract:

The experimental study of the silicone rubber and EPDM insulator eroded by highly concentrated particles were carried out and a series of dynamic recession images of insulation surface were obtained successfully based on real-time X-ray radiography technique(RTR). The experimental results show that(1)The transient ablation rate of silicone rubber increased rapidly within the first two seconds and it would become stable after two seconds. The transient ablation rate of EPDM increased rapidly within the first second and then it would become stable.(2)The results indicate that the characteristic of resistant to erosion of particles of EPDM insulator is better than that of silicone rubber. Silicone rubber insulation is not suitable for the application of high overload motor.(3)The ablation rate of insulation eroded by highly concentrated particles is higher than that in normal condition. The mechanism is that the insulation is eroded by both mechanical abrasion and thermochemical ablation due to high-temperature particles. The results are important to ablation mechanism research and ablation modeling of silicone rubber and EPDM insulator. 