摘要
液滴撞击固体表面是自然界中最常见的物理现象之一,宏观液滴与微液滴的撞击过程因有较强的传热传质性能而被广泛地应用于工农业等领域。通过微液滴产生装置产生微液滴,利用高速数码摄像系统记录下液滴撞击表面的过程,最后通过程序处理液滴动态过程图,分析了表面微结构对液滴最大铺展系数以及振动过程的影响规律。实验结果表明:最大铺展系数随液滴撞击速度的增大而增大,受表面微结构的形貌特征影响较小;将液滴撞击表面后的振动过程等效为单自由度的阻尼弹簧系统,发现表面微结构对于液滴振动阻尼系数有影响,但是对于弹性常数的影响不大。
The droplet impacting solid surface is the most common physical phenomenon in the natural world and the impacting process of macro-droplet and micro-droplet is widely used in the industrial and agricultural fields due to its strong heat-transfer character. The experiment analyzes the influence laws of surface micro-structure on maximum spreading coefficient and vibration process by generating micro-droplet with micro-droplet generator, recording the process of droplet impacting the surface with high-speed digital camera and processing the dynamic process diagram with programs. The experiment result indicates that the maximum spreading coefficient increases along with the increase of droplet impacting speed and is less affected by the shape characteristics of surface micro-structure, if the vibration process after droplet impacting the surface is equivalent to the single-degree-of-freedom spring-damper system, it can be found that the surface micro-structure has an influence on the damping coefficient of droplet vibration but not on the elastic constant.
引文
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