Investigated in this paper is the coupled fluid–body motion of a thin solid body undergoing a skimming impact on a shallow-water layer. The underbody shape (the region that makes contact with the liquid layer) is described by a smooth polynomic curve for which the magnitude of underbody thickness is represented by the scale parameter C. The body undergoes an oblique impact (where the horizontal speed of the body is much greater than its vertical speed) onto a liquid layer with the underbody’s trailing edge making the initial contact. This downstream contact point of the wetted region is modelled as fixed (relative to the body) throughout the skimming motion with the liquid layer assumed to detach smoothly from this sharp trailing edge. There are two geometrical scenarios of interest: the concave case ( $$C<0$$ producing a hooked underbody) and the convex case ( $$C > 0$$ producing a rounded underbody). As C is varied the rebound dynamics of the motion are predicted. Analyses of small-time water entry and of water exit are presented and are shown to be broadly in agreement with the computational results of the shallow-water model. Reduced analysis and physical insights are also presented in each case alongside numerical investigations and comparisons as C is varied, indicating qualitative analytical/numerical agreement. Increased body thickness substantially changes the interaction structure and accentuates inertial forces in the fluid flow.

中文翻译：

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光滑成形体在浅液层上的撇取冲击和回弹

本文研究的是薄固体​​在浅水层上发生掠过撞击时的流体-体耦合运动。车身底部形状（与液体层接触的区域）由平滑的多项式曲线描述，车身底部厚度的大小由比例参数 C 表示。 车身受到斜向撞击（车身的水平速度远大于其垂直速度）到液体层，底部的后缘进行初始接触。润湿区域的这个下游接触点在整个撇脂运动中被建模为固定（相对于身体），假设液体层从这个尖锐的后缘平滑地分离。有两种感兴趣的几何场景：凹面情况（$$C< 0$$ 产生钩状底部）和凸面情况（$$C > 0$$ 产生圆形底部）。随着 C 的变化，运动的回弹动力学被预测。介绍了小时间进水和出水的分析，表明与浅水模型的计算结果大体一致。在每种情况下，随着 C 的变化，还提供了简化的分析和物理见解以及数值调查和比较，表明定性分析/数值一致。增加的主体厚度显着改变了相互作用结构并加强了流体流动中的惯性力。介绍了小时间进水和出水的分析，表明与浅水模型的计算结果大体一致。在每种情况下，随着 C 的变化，还提供了简化的分析和物理见解以及数值调查和比较，表明定性分析/数值一致。增加的主体厚度显着改变了相互作用结构并加强了流体流动中的惯性力。介绍了小时间进水和出水的分析，表明与浅水模型的计算结果大体一致。在每种情况下，随着 C 的变化，还提供了简化的分析和物理见解以及数值调查和比较，表明定性分析/数值一致。增加的主体厚度显着改变了相互作用结构并加强了流体流动中的惯性力。