点火药量对双脉冲固体火箭发动机点火过程影响

Impact of ignition charge on ignition process of dual-pulse solid rocket motor

为了确定第二脉冲点火药量对双脉冲发动机点火过程的影响规律,以某双脉冲固体火箭发动机为模型,采用轴对称非定常Navier-Stokes方程和标准k-ε湍流模型,对第二脉冲点火过程进行了仿真,研究了点火装置工作持续时间和点火燃气流量对于点火延迟的影响。研究结果表明:点火燃气流量相同时,增加点火装置工作持续时间可以有效减小第二脉冲点火延迟,该点火延迟存在一个极限值即最小点火延迟。不同点火燃气流量对应不同的最小点火延迟,点火燃气流量越大,最小点火延迟越小,两者之间存在着负指数关系。在设计第二脉冲点火药量时,自由容积应选取为第一、二脉冲自由容积之和更加合理。

In order to find out the impact of ignition charge on ignition process in the second pulse,a model was established. The axisymmetric unsteady Navier-Stokes equation and the standard k-ε turbulence model were used to simulate the second pulse ignition process. Based on that,the impacts of the igniter working duration and ignition gas flow rate on the ignition delay were studied. The results showed that: when the ignition gas flow rate was constant, increasing the igniter working duration can effectively shorten the second pulse ignition delay,and there existed a limit value of the ignition delay,which was defined as the minimum ignition delay. Different ignition gas flow rates corresponded to different minimum ignition delay,and the bigger ignition gas flow rate indicated the smaller minimum ignition delay. The ignition gas flow rate had a negative exponential relationship with the minimum ignition delay. Choosing the free volume as the sum of the first and second pulse free volumes is more reasonable when calculating the second pulse ignition charge.