We report frozen ice patterns for the water droplets impacting on a cold substrate through fast-speed images. These patterns can be manipulated by several physical parameters (the droplet size, falling height, and substrate temperature), and the scaling analysis has a remarkable agreement with the phase diagram. The observed double-concentric toroidal shape is attributed to the correlation between the impacting dynamics and freezing process, as confirmed by the spatiotemporal evolution of the droplet temperature, the identified timescale associated with the morphology and solidification ($t_{inn}\simeq {\tau }_{sol}$), and the ice front-advection model. These results for frozen patterns provide insight into the complex interplay of the rapid impacting hydrodynamics, the transient heat transfer, and the intricate solidification process.

中文翻译：

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撞击液滴的冻结模式：从圆锥形尖端到环形形状

我们通过快速图像报告了影响冰冷基材上的水滴的冻结冰模式。这些模式可以通过几个物理参数（液滴大小，下降高度和基材温度）进行控制，并且结垢分析与相图具有显着的一致性。观察到的双同心圆环形状归因于冲击动力学与冻结过程之间的相关性，这已通过液滴温度的时空演变，与形态和凝固相关的确定时间尺度得到证实（${Ť}_{\mathrm{一世}ññ}\simeq {\tau }_{sØ升}$）和冰前平流模型。冻结模式的这些结果提供了对快速影响的流体动力学，瞬态传热和复杂的固化过程之间复杂相互作用的洞察力。