双药室喷管气流反推减后坐机理

为解决发射高初速榴弹的榴弹机枪系统后坐力大的问题，提出了一种双药室拉瓦尔喷管气流反推减后坐技术.设计了适用于高速榴弹机枪系统的双药室拉瓦尔喷管减后坐装置，利用一维非定常流理论推导了双药室喷管低后坐武器的内弹道阶段和后效期阶段的气体动力学方程；将试验测得的压力峰值、弹丸初速及后坐力与仿真数值进行对比，验证建立的双药室喷管气流反推减后坐计算模型的正确合理性；计算双药室喷管低后坐武器后药室、前药室、导气室及喷管气室的压力，并分析压力参数随时间变化规律；对比分析双药室喷管武器与普通武器的膛压曲线、弹丸速度曲线，重点分析双药室喷管内气流压力、温度、密度和速度随时间变化曲线及在喷管内分布状况；探讨了后药室装药量、喷管导气孔直径及喷管内经对武器喷管反推力、喷管减后坐效率、弹丸初速等武器发射性能的影响.研究结果表明，在保持弹丸初速不变的情况下，合理匹配双药室减后坐结构参数，采用双药室喷管气流减后坐技术可实现武器低后坐发射的目的.
To solve the problem of overload-recoil when launching the high muzzle velocity grenade by grenade machine gun system (GMGS), a new effective technology of reducing the recoil force using laval nozzle device with double chambers is presented, and the device is designed and applied to the GMGS. Based on unsteady one-dimensional gas dynamic theory, the interior ballistic duration and after-effect period gas dynamics equations of the recoil device were derived. The rationality of the built mathematical model was validated by contrasting the test date and simulation results. The gas pressure of back chamber, front chamber, gas operated device and nozzle chamber was calculated and the variation laws were analyzed. The bore pressure and muzzle velocity of laval nozzle device with double chambers and conventional weapons were compared. The distribution of gas parameter in nozzle with time and the distribution of gas parameter in nozzle with position were selectively analyzed. The influence of launching performance of laval nozzle with double chambers were discussed. The results show that the GMGS can achieve low recoil launching by setting reasonable parameters of the laval nozzle device with double chambers, while the projectile velocity is unaffected.