考虑空化效应的某软后坐火炮制退机液压阻力系数研究

Research on Hydraulic Resistance Coefficient of a Soft Recoil Gun Brake with Cavitation Effect

针对某新型软后坐火炮制退机的恒定液压阻力系数无法准确描述制退机性能的问题,基于计算流体力学方法计算了火炮后坐复进不同阶段的液压阻力系数,其中重点考虑了空化效应对液体流动的影响。分别对前冲、后坐及复进阶段,建立了带有中心斜孔的筒内壁沟槽主流等效模型、不带中心斜孔的筒内壁沟槽主流等效模型及筒外壁沟槽主流等效模型。采用Mixture多相流模型与标准k-ε湍流模型,得到了不同沟槽深度及运动速度下液压阻力系数K的值。结果表明,液压阻力系数在前冲阶段为4.2~6.0、在后坐阶段为1.8~2.8、在复进阶段为1.6~2.4;且液压阻力系数随沟槽深度的增大而减小,随速度的增大先减小,达到发生空化的速度后增大。该研究可为某软后坐火炮的反后坐装置设计及试验测试提供支撑。

In order to solve the problem that the constant hydraulic resistance coefficient of a new type of soft recoil gun recoilbrake cannot accurately describe its performance,the hydraulic resistance coef-ficients at different recoil stages were calculated based on computational fluid dynamics,especially the effects of cavitation on liquid flow were studied.The equivalent flow field model for the groove on inner wall of the cylinder with/without a central inclined hole and the groove on outer wall at forward,recoil and recuperate stage were established,respectively.Then the hydraulic resistance coefficients K for different groove depths and velocities were calculated by Mixture multiphase flow model and standard k-8 turbulence model.The results show that the hydraulic resistance coefficient is 4.2~6.0 at forward stage,1.8~2.8 at recoil stage and 1.6~2.4 at recuperate stage.The resistance coefficient decreases with the increase of groove depth,first decreases with the increase of velocity and then increases after reaching the velocity at which cavitation occurs.The research can provide support for the design and test of recoil mechanism of a soft recoil gun.