Abstract

The present study investigates the effects of droplet impact height, tilt angle, and surface temperature on the impact and freezing process of water droplet on a cold surface by using a Motionpro high-speed camera and a DSA-30 droplet surface analyzer. The temperature of the plate was changed from an ambient temperature of 24.0°C to \(-10.0^{\circ}\)C, while three impact heights (\(H\) = 100, 150 and 200 mm) were set. The data indicated that increasing impact height led to increase in the maximum spreading diameter and maximum endpoint displacement, but its effect on droplet spreading time was not significant. With decreasing the surface temperature, the rate of change in the droplet diameter was smoother and the droplet freezing time reduced. Moreover, at low Weber number (\(We < 200\)), the impact height has less effect on the freezing time of the droplet. Besides, compared with the horizontal plate, the droplet freezing time on plate tilted at 30° was higher for the same impact height.

中文翻译：

---

水滴在碳纤维板上的冲击和冻结过程的可视化研究

摘要

本研究利用Motionpro高速相机和DSA-30水滴表面分析仪研究了水滴撞击高度、倾斜角度和表面温度对水滴在冷表面上的撞击和冻结过程的影响。板的温度从环境温度 24.0°C 更改为 \(-10.0^{\circ}\) C，同时设置三个冲击高度（\(H\)  = 100、150 和 200 mm）。数据表明，增加撞击高度会导致最大扩散直径和最大端点位移的增加，但对液滴扩散时间的影响并不显着。随着表面温度的降低，液滴直径的变化率变得更加平滑，液滴冻结时间减少。此外，在低韦伯数（\(We < 200\)）下，撞击高度对液滴冻结时间的影响较小。此外，与水平板相比，相同冲击高度下，倾斜30°的板上液滴冻结时间更长。