【摘要】 利用高速摄像仪记录了液滴在低速下撞击不同亲疏水性固体表面的过程,记录速度为4 000fps。实验在常温常压下进行,液滴的初始直径为(2.25±0.02)mm,对不同固体材料壁面,液滴以3种速度撞击,并采用图像处理技术获取液滴以不同速度撞击不同固体材料壁面下的形态变化参数。结果表明:不同撞击速度、不同亲疏水性固体材料壁面对液滴铺展直径D、液滴高度h等参数均有重要影响;同种速度下,亲水的石英玻璃壁面最大铺展直径D较大、铺展所需时间较长、回缩程度小,铺展后达到平衡状态的震荡周期数少,液滴高度h较小;同种固体表面,液滴撞击速度增大(0.94~1.64m/s)时,最大铺展直径D依次增大,液滴高度h从最低点回升直至平衡的震荡周期数依次减少,达到平衡的时间变短。更多还原

【Abstract】 Impact of droplets with low velocity on surfaces with different hydrophilicity/hydrophobicity was studied experimentally with a high speed camera at 4 000 fps.Experiments were performed at normal pressure and temperature.Droplets with diameter of(2.25±0.02)mm impacting on different solid surfaces at three kinds of velocity,and morphological parameters such as spreading diameter Dand drop height hof impacting droplet were obtained using image processing technology under different circumstances.Results show that Dand hare both greatly influenced by impacting velocity of droplet and the hydrophilicity/hydrophobicity of solid surface.At the same speed,the maximum spreading diameter Don hydrophilic quartz glass is larger than others,with smaller degree of retraction.And the spreading process requires for longer time.On thesame solid surface,the maximum spreading diameter Dincreases with impacting droplet velocity(0.94m/s to 1.64m/s).Meanwhile,the cycles of drop height oscillation from lows to highs until balance decrease and the time required for balance decreases.更多还原