基于微波干涉测速技术的二级轻气炮/火炮内弹道参数诊断

测量二级轻气炮/火炮弹丸在内弹道的速度历程，对轻气炮/火炮的设计、内弹道计算、弹道异常现象诊断分析具有重要作用。因为不同波长微波的传输特性在不同炮管中不同，不同目标的反射特性也不同，为获得最佳的测试结果，设计了两个波长的微波干涉测速系统。对二级轻气炮和高速火炮的内弹道速度进行了连续测量，并利用短时傅里叶变换与相位计算相结合的方法进行了数据处理。实验成功获取了完整的内弹道数据，所测弹丸炮口速度与光束遮断测速装置测试结果差异小于0.5%。通过对内弹道实验数据的分析，证实了二级轻气炮在某些装填条件下易出现碎弹现象。此外，首次观测到二级炮内弹道内前冲气体速度历史，可为研究高速气体的温度、压力、电离等状态提供数据支撑。

Microwave velocity interferometry for the parameter diagnosis of the interior ballistic of a two-stage light gas gun or powder gun

The measurement of the interior ballistic projectile velocity in a two-stage light gas gun or powder gun and the observation of the state of the precursor gas in the launch tube are very important for the design and calculation of the interior ballistic and for the analysis of the abnormal ballistic. In order to obtain the better results, two microwave interferometers in the Ka-band and X-band were designed by the Dopple principle, since the transmission and reflection characteristics of microwave are related with the caliber of launch tube and objects materials respectively. A combination of the short-time Fourier transform and phase calculation was used to process the interference signal, and then the velocity, acceleration, displacement, projectile bottom pressure and other information were obtained by calculation. Complete interior ballistic data for a two-stage light gas gun and a high-speed powder gun were obtained experimentally. The difference in the projectile velocity measured by the microwave interferometer and the optical beam blocking (OBB) device is less than 0.5%. Moreover, it was demonstrated in our experiments that under some conditions, shock waves may cause premature breaking of the diaphragm in the high pressure section, which results in the projectile having a secondary loading at high pressure, and then becoming fragmented with a probability. In addition, based on the reflection and transmission characteristics of the ionized gas at different microwave wavelengths, the velocity of the precursor H₂ gas in the launch tube of the two-stage light gas gun was measured using the X-band microwave interferometer for the first time, which can provide data for studying the temperature, pressure, ionization and other states of the high-speed ionized gas.