小空化数下带尾翼射弹超空泡减阻试验与数值模拟

Experimental and numerical investigation of supercavity drag reduction of wing-projectiles under small cavitation number

为探究水下高速带尾翼射弹的超空泡减阻特性,利用自行研制的水下测速系统,对所设计的几种结构的带尾翼射弹模型进行了带尾翼超空泡射弹从空气入水的试验研究。通过试验数据的分析和处理,获得小空化数下带尾翼超空泡射弹的阻力系数。采用N-S方程、压力隐式算子分裂(PISO)算法、大涡模拟湍流模型和流体体积函数(VOF)方法,对绕三维带尾翼射弹非定常空泡流动进行数值模拟,计算结果与试验数据吻合较好。分析了小空化数下带尾翼射弹超空泡的减阻效果,最大减阻率可达93.1%。与普通射弹的超空泡流特性相对比,尾翼结构对超空泡射弹的阻力特性影响不大,但可以显著提高射弹运动的稳定性。

In order to investigate the supercavity drag reduction characteristics of underwater high-speed wing-projectiles,wing-projectile models with multi-configuration parameters are designed.The experiments of the supercavitating wing-projectile ripping from air into water are carried out with the self-developed underwater speed measuring system.By analyzing the experimental data,the drag coefficients of the supercavitating wing-projectile small cavitation number are determined.Based on the N-S equations and the algorithm of the pressure-implicit with splitting of operators(PISO),the numerical simulation of the three-dimensional unsteady cavitating flow around the wing-projectile is implemented by adopting the large eddy simulation(LES) turbulence model and VOF method.The numerical simulation result agrees well with the experiment.On the basis of experimental data and numerical simulation,the supercavity drag reduction effect of the wing-projectile under the small cavitation number is analyzed and the drag reduction ratio can reach 93.1% approximately.Finally,the supercavitating flow of general projectile is investigated.The results show that the wing structure has little influences on the drag characteristics of the supercavitating projectile and the wing-projectile has good navigation stability.