High-speed jet formation after solid object impact.
High-speed jet formation after solid object impact.
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DOI：
10.1103/physrevlett.102.034502
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发表时间：
2008-09
影响因子：
8.6
通讯作者：
S. Gekle;J. Gordillo;D. van der Meer;D. Lohse
中科院分区：
文献类型：
--
作者：
S. Gekle;J. Gordillo;D. van der Meer;D. Lohse
一个圆盘撞击水面会产生一个撞击坑，撞击坑塌陷后会产生一股强劲的射流。在撞击时，形成轴对称的空气腔，并最终在腔的一半处的单个点处夹断。观察到两个快速尖锐的射流从关闭位置向上和向下喷射，然后关闭位置变成了由局部双曲线流型包围的驻点。然而，这种流动不是供给射流的机制。使用高速成像和数值模拟，我们表明，喷射是由本地流周围的射流，这是被迫碰撞腔壁的基础。我们展示了如何著名的理论崩溃的空隙（使用线的对称轴上的水槽）可以继续超越夹断，以获得一个新的和定量的模型，射流形成同意以及与数值和实验数据。
A circular disc hitting a water surface creates an impact crater which after collapse leads to a vigorous jet. Upon impact an axisymmetric air cavity forms and eventually pinches off in a single point halfway down the cavity. Two fast sharp-pointed jets are observed shooting up- and downwards from the closure location, which by then has turned into a stagnation point surrounded by a locally hyperbolic flow pattern. This flow, however, is not the mechanism feeding the jets. Using high-speed imaging and numerical simulations we show that jetting is fed by the local flow around the base of the jet, which is forced by the colliding cavity walls. We show how the well-known theory of a collapsing void (using a line of sinks on the symmetry axis) can be continued beyond pinch-off to obtain a new and quantitative model for jet formation which agrees well with numerical and experimental data.