While the droplet impact dynamics on stationary superhydrophobic surfaces has been extensively studied, the dynamic behaviors of impact droplets on moving superhydrophobic surfaces have received less attention. Here, we report the droplet impact dynamics on a moving superhydrophobic surface. We show that compared to the stationary surface, the moving superhydrophobic surface breaks the symmetry in both droplet spreading and retracting. Specifically, the shear force exerted by the moving surface acting on the impact droplet enlarges the maximum spreading in the moving direction, and thus, the droplet contact time is reduced. The contact time of impact droplets was examined thoroughly under the effects of the droplet impact (normal) and the wall moving (tangential) Weber numbers. We provide a scaling analysis to explain how the contact time depends on the normal and tangential Weber numbers. Our experimental investigation and theoretical analysis provide insight into the droplet impact dynamics on moving superhydrophobic surfaces.

中文翻译：

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减少液滴撞击移动超疏水表面的接触时间

虽然液滴在静止超疏水表面上的撞击动力学已得到广泛研究，但撞击液滴在移动超疏水表面上的动力学行为却很少受到关注。在这里，我们报告了移动的超疏水表面上的液滴撞击动力学。我们表明，与静止表面相比，移动的超疏水表面破坏了液滴扩散和缩回的对称性。具体而言，运动表面施加在撞击液滴上的剪切力扩大了运动方向上的最大扩散，从而减少了液滴接触时间。在液滴撞击（正常）和壁移动（切向）韦伯数的影响下，彻底检查了撞击液滴的接触时间。我们提供了一个比例分析来解释接触时间如何取决于法向和切向韦伯数。我们的实验研究和理论分析提供了对移动超疏水表面上液滴撞击动力学的深入了解。