弹尾弹射装置间隙密封的火药气体动力学

摘要

针对弹尾开孔安装用于侵彻数据回收的弹射装置后,存在的弹射间隙会使弹体内的测试装置受到火药气体侵蚀破坏的问题,设计了间隙密封结构,对流经间隙的火药气体进行了气体动力学的建模分析,并对密封结构进行了膛压和密封空腔压强测试.结果表明:火药燃烧产生的气体为可压缩性气体,在药室和收缩的间隙通道中为亚声速流动状态,而在扩张的密封空腔中为超声速流动状态;在弹底火药气体温度为2 166.5 K、密度为360 kg/m3、压强为242.9 MPa的条件下,经过密封装置的密封后,密封空腔内的残余气体压强为0.49MPa.试验所得密封空腔内的最大压强为0.18MPa,与模型计算结果基本吻合.%The present study addresses the potential damage that might be suffered by the test device of a projectile body as a result of the gun powder gas coming from the clearance opened in the projection base for installing an ejection device for the recovery of the penetration data.A seal structure of the clearance was designed and a model was built for analyzing the dynamical state of the gunpowder gas flowing in the clearance.The chamber pressure and the seal cavity pressure of the seal structure were tested by experiment.The results show that the gas in the gunpowder combustion was a compressible gas,flowing in a subsonic condition in the powder chamber and the contracting clearance channel,but in a supersonic condition in the expansion seal cavity.When the gunpowder gas in the projection base was sealed by the seal structure and kept at a temperature of 2 166.5 K,a density of 360 kg/m3 and a pressure of 242.9 MPa,the pressure for the residual gas in the seal cavity was 0.49 MPa.The maximum pressure of the test curve in the seal cavity pressure was 0.18 MPa,fairly consistent with the theoretical results.These results can serve as reference for fabricating the seal of the high temperature and high pressure gunpowder gas in the projection base.