固体火箭发动机零维内弹道点火模型与计算

Modeling and Calculation of Zero-dimensional Internal-ballistics Ignition Process of Solid Rocket Engine

点火过程是内弹道的初始阶段,但由于点火过程的复杂性以及点火机理仍然不完善,点火过程始终不能与内弹道有机结合,使得目前工程上的内弹道计算只能忽略点火过程而直接选择点火压强作为计算初始点。以零维内弹道理论为基础,建立了点火过程3个阶段,即点火诱导期、火焰传播期和充气期的简化理论模型,可以与零维内弹道有机结合,从而完成了内弹道从环境压强(而不是点火压强)开始计算的完整过程。通过实例计算与验证,该模型能够很好展示在点火阶段燃烧室压强的建立过程,并可以计算得到点火延迟时间、火焰传播时间、点火药流量等点火参数,具有较高的预示精度,满足工程计算要求。研究表明,建立的点火过程理论模型与传统零维内弹道一样计算简便快捷,并具有较好精度的工程应用化特点。研究结果对于完善固体火箭发动机内弹道理论、提高固体火箭发动机内弹道预示精度,均具有重要的实际应用意义。由于采用了简化的点火过程理论模型,该结果不能直接用于点火性能的研究,只能用于零维内弹道性能的预估与计算。

The ignition process is the initial stage of internal ballistics,but due to the complexity of the ignition process and the imperfect ignition mechanism,the ignition process can never be organically combined with internal ballistics,and the current engineering internal-ballistics calculation can only ignore the ignition process and directly select the ignition pressure as the initial calculation point.Based on the zero-dimensional internal-ballistics theory,a simplified theoretical model of three stages of the ignition process,namely duration of time lag,flame-spreading interval and chamber-filling interval,was established.It can be organically combined with the zero-dimensional internal-ballistics,thus completing the whole process of internal-ballistics calculation from the ambient pressure(not the ignition pressure).Through example calculation and verification,this model can well demonstrate the process of establishing chamber pressure during the ignition stage,and can calculate ignition parameters such as ignition delay time,flame-spreading time,and ignition powder flow rate.It has high predictive accuracy and meets the requirements of engineering calculations.Research shows that the established theoretical model of ignition process,like traditional zero-dimensional internal ballistics,has the engineering application characteristics of simple and fast calculation,and good accuracy.The method has important practical application significance to perfect internal-ballistics theory,and to improve prediction accuracy of internal ballistics of solid rocket motor.Due to the use of a simplified ignition-process theoretical-model,this study cannot be directly applied to the study of ignition performance,but can only be used for the prediction and calculation of zero-dimensional internal-ballistics performance.