初容室容积对燃气弹射载荷与内弹道性能影响

为研究初容室容积变化对燃气弹射载荷与内弹道性能的影响,建立了含二次燃烧和尾罩运动边界的二维轴对称数值模型。在实验数据验证模型可靠性的基础上,研究了初容室容积变化导致流场结构和二次燃烧核心区域改变的机理,分析了弹射过程中影响建压的主导因素,得到了不同初容室容积下的流场、载荷和内弹道性能规律。结果表明:随着初容室高度的增加,燃气射流反射点由筒底转移至筒壁面,二次燃烧核心区域由发射筒上部转移至下部;对于弹底初始冲击压力峰值,容积因素占据主导,对于二次压力峰值,总压因素占据主导;导弹加速度峰值和出筒速度先减小后增加,出筒时间先变长后变短。实验装置初容室高度增加100mm,为最优内弹道设计方案。

Influence of Volume in Initial Chamber on the Flow Load and Interior Ballistic Property of Gas Ejection

A two dimensional axisymmetrical numerical flow model with secondary combustion and trail cover moving boundary is established to study the influence of volume change in initial chamber on the load and the internal ballistic property. On the basis of experimental data verifying the reliability of model, the mechanism of flow field and the secondary combustion core region change caused by volume change of initial chamber is investigated, and the dominant factor influencing building pressure in the rejection process is analyzed, and flow field, load and internal ballistic characteristics of different initial volume are obtained. The results show that with the increase of height in the initial chamber, the reflection point of jet flow is transferred from the cylinder bottom to the cylinder wall, and the secondary combustion core region is transferred from the upper part of cylinder to the lower part. For the initial pressure peak, volume factor is leading, and for the second pressure peak, the total pressure is leading. The peak values of missile acceleration and the outlet velocity decreases firstly and then increases, and the time out of tube becomes longer, and then becomes the shorter. The height of the initial chamber of the experimental device increases by 100mm, which is one of the most optimal interior ballistic designs.