论文标题
球进入旋转液体
Water entry of spheres into a rotating liquid
论文作者
论文摘要
从实验，数值和理论上研究了沉重的，非旋转球的水进入水中时的瞬态腔动力学。我们表明，池旋转可以推进腔体类型的过渡 - 从深密封到表面密封 - 以降低过渡性弗洛德数的标记。无量纲的旋转数$ \ MATHCAL {S} \equivΩR_0/U_0 $在瞬态腔动力学上的作用已揭幕，其中$ r_0 $是球形半径，$ω$ the Angular liquid的角度速度，$ u_0 $ u_0 $ u_0 $。旋转的背景液体对腔进化具有两个可分离的影响。首先，由于中心效应引起的水下压力场增加，其次，水面附近的空腔颈气流压力降低。深密封的非二维捏时间显示了对Froude编号的强大的1/2幂律依赖性，但具有增加$ω$的预先成品。我们的发现表明，旋转背景液体对水入口的影响可以追溯到初始阶段飞溅和近表面腔动力学的微妙差异。
The transient cavity dynamics during water entry of a heavy, non-rotating sphere impacting a rotating pool of liquid is studied experimentally, numerically, and theoretically. We show that the pool rotation advances the transition of the cavity type - from deep seal to surface seal - marked by a reduction in the transitional Froude number. The role of the dimensionless rotational number $\mathcal{S} \equiv ωR_0/U_0$ on the transient cavity dynamics is unveiled, where $R_0$ is the sphere radius, $ω$ the angular speed of the liquid, and $U_0$ the impact velocity. The rotating background liquid has two discernible effects on the cavity evolution. Firstly, an increase in the underwater pressure field due to centripetal effects, and secondly a reduction in the pressure of airflow in the cavity neck near the water surface. The non-dimensional pinch-off time of the deep seal shows a robust 1/2 power-law dependence on the Froude number, but with a reducing prefactor for increasing $ω$. Our findings reveal that the effects of a rotating background liquid on the water entry can be traced back to the subtle differences in the initial stage splash and the near-surface cavity dynamics.
