战斗机武器外挂投放与内埋投放比较

为了研究弹体外挂投放与内埋投放的区别,利用基于Menter SST湍流模式的改进延迟分离涡模拟(IDDES)方法以及重叠网格技术,分别对亚声速和超声速来流条件下,同一弹体外挂投放和内埋投放进行了数值模拟,得到了亚声速和超声速条件下外挂投放与内埋投放弹体的下落规律。通过对比分析表明:亚声速和超声速来流条件下,内埋投放由于受舱体内强非定常流场以及舱体唇口剪切层的影响,弹体受很大的抬头力矩,弹体姿态角变化较大,投放特性劣于外挂投放。进一步研究表明:在弹射时给弹体一定的低头角速度,使弹体以低头姿态穿越剪切层,则可以大幅度降低剪切层带来的不利影响,提高内埋投放弹体分离品质。

Comparison between external store separation and buried store separation of fighter

To analyze the difference between external store separation and buried store separation,several separation cases were simulated using the same missile under the conditions of both subsonic and supersonic inflow.Improved delayed detached eddy simulation (IDDES) method based on Menter SST turbulence model and overset mesh method were employed.Different trajectories of missile under different separation conditions were obtained.The results show that under both subsonic and supersonic inflow conditions,the buried missile is impacted by the strong unsteady flow field inside the cavity and shear layer at the cavity lip.It gives the missile big upward force moment which leads to obvious attitude angle variation.Compared with external store separation,the quality of buried store separation is much worse.If the missile is given a downward angular velocity and goes through the shear layer in pitch down angle,the side effects caused by shear layer can be substantially reduced.By using this launching method,the buried store separation quality is improved apparently.