摘要
为了研究在低温寒冷工作条件下单兵火箭发射过程中声、光、焰、烟等缺陷的抑制方法,设计了将防冻液柱放置在发射筒尾管中作为平衡体的实验方案。实验中采用高速摄影系统观察了超声速燃气射流驱动防冻液柱在大气环境中的扩散过程,并利用压电式传感器测得了发射筒周围的冲击波超压值,对比了燃气驱动防冻液柱和液体水柱两种状态下射流流场的测试结果。实验结果表明,由于液体柱的阻碍作用,射流流场发展初期的径向发展速度相比于轴向发展速度更快。随着射流流场的逐渐发展,出现了Kelvin-Helmholtz不稳定效应。以防冻液柱为平衡体时,弹丸所获初速更高,由于防冻液气化潜热较高,相比于液体水气化时吸收了更多的燃气能量,降低了射流特征参数。通过与以液体水柱为平衡体的射流流场对比,发现以防冻液柱为平衡体时整个测点区域的噪声声压级峰值均有所降低,声压级降低了1.5~3.5d B,验证了此方案的可行性。
In order to study the suppression method of defects such as sound, light, flame, and smoke in the process of individual rocket launch under the condition of the low temperature, an experimental scheme of placing the antifreeze column in the launch cylinder liner as a balance body was designed. The diffusion process in the atmospheric environment of the antifreeze column driven by supersonic gas jet was observed by using a high-speed photographic system in the experiment. The overpressure of the shock wave around the launch cylin- der was also measured by using the piezoelectric sensors. The test results of the jet flow field in two states of anti- freeze column and water column driven by supersonic gas jet were compared. The experimental results show that, due to the hindering effect of the liquid column, the radial development speed in the initial stage of the de- velopment of the jet flow field was faster than in axial direction. With the gradual development of the jet flow field, it appeared unstable of Kelvin-Helmholtz. Antifreeze column was put in the tail tube as a balance body, the velocity of the projectile was faster. As the latent heat of vaporization of antifreeze is higher and it absorbed more energy of gas compared to the water, the antifreeze column reduced the jet characteristic parameters. It is found that the sound pressure level of the whole measured points are reduced when the antifreeze column is a bal- ance body compared with the results of jet flow field of water column being a balance body. The sound pressure level decreases by 1.5 - 3.5dB. It verifies the feasibility of the scheme.
出处
《推进技术》
EI
CAS
CSCD
北大核心
2017年第8期1726-1731,共6页
Journal of Propulsion Technology
关键词
低温
超声速燃气射流
防冻液柱
液体水柱
声压级
Low temperature
Supersonic gas jet
Antifreeze column
Water column
Sound pressurelevel
