气动灭火炮弹体橡胶圈仿生凹坑表面减阻特性

针对气动灭火炮炮弹发射过程中弹体橡胶密封圈与炮管之间摩擦阻力大的问题,将仿生凹坑表面减阻技术应用于弹体橡胶密封圈上。建立气动灭火炮橡胶密封圈仿生凹坑减阻运动模型,采用数值模拟方法,研究弹体橡胶密封圈仿生凹坑特征直径及弹体速度对橡胶密封圈与炮管之间摩擦阻力的影响。结果表明:在相同的弹体速度下,当灭火炮弹体橡胶密封圈仿生凹坑特征直径为2mm时,减阻效果最佳,凹坑特征直径为4mm时,减阻效果最差;最大减阻率为17.191%,最小减阻率为3.158%。仿生凹坑中存储的润滑油在弹体运动时,润滑油产生拖拽泼洒而溢流到炮管内壁,对炮管内壁和橡胶密封圈起到润滑作用,达到减小摩擦阻力以及提高炮弹发射速度的目的。

Characteristics of drag reduction of bionic dimpled surface of shell rubber ring of aerodynamic extinguishing cannon

To reduce the frictional resistance between the barrel and the rubber seal ring of shell body during the launching process of aerodynamic extinguishing cannon,a bionic drag reduction technology of dimpled surface was applied to the rubber ring.The motion model was established for the dimpled drag reduction surface of the rubber seal ring.The effects of the characteristic diameter of bionic dimples on the rubber seal ring and the shell speed on the frictional resistance between barrel and shell body were investigated by numerical simulation.Results show that,at the same shell speed,with dimple characteristic diameter of 2 mm,the highest drag reduction effect,17.191%,was obtained;with dimple characteristic diameter of 4 mm,the lowest drag reduction effect,3.158,was obtained.It is revealed that the mechanism of the drag reduction is that,during moving inside the barrel,the lubricant stored in the dimples on the seal ring of shell spills over to lubricate the barrel wall and seal ring,which reduces the frictional resistance and thus increases the launching speed.