Laboratory Measurements of Small Raindrop Distortion. Part I: Axis Ratios and Fall Behavior
Laboratory Measurements of Small Raindrop Distortion. Part I: Axis Ratios and Fall Behavior
复制标题
小雨滴畸变的实验室测量。
DOI：
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发表时间：
1991
期刊：
影响因子：
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通讯作者：
H. Ochs
中科院分区：
文献类型：
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作者：
K. Beard;R. Kubesh;H. Ochs
摘要通过对直径为0.70 ~ 1.54 mm的雨滴轴比和落下行为的一系列实验室测量，研究了Gunn假设的毫米直径雨滴涡流脱落和水滴振荡之间的共振相互作用。使用孔喷射液滴发生器以终端速度产生液滴，并使其下降几米，以便在使用频闪照片记录液滴形状之前，初始振荡（在射流破裂期间产生）衰减到可忽略不计的振幅。测量的轴比在最小尺寸（d = 0.70 ~ 0.96 mm）处具有平衡值，但在中等尺寸（d = 1.04 ~ 1.29 mm）处略高于平衡值。当平均轴比大于平衡时，最大尺寸（d = 1.40-1.54 mm）的轴比散点在平衡上方和平衡下方都有较大的数量级。在d = 0.82-1.0时，除了最小的液滴外，所有液滴都显示出从终端速度的1%左右的侧向漂移……
Abstract The resonant interactions between eddy shedding and drop oscillations postulated by Gunn for millimeter diameter raindrops were investigated in a series of laboratory measurements of axis ratio and fall behavior for water drops of d = 0.70–1.54 mm. Drops were produced at terminal velocity using a orifice-jet drop generator and allowed to fall several meters so that the initial oscillations (produced during jet break up) decayed to a negligible amplitude before the drop shape was recorded using stroboscopic photographs. The measured axis ratios had equilibrium values for the smallest sizes (d = 0.70–0.96 mm), but scattered somewhat above equilibrium at intermediate sizes (d = 1.04–1.29 mm). An order of magnitude larger scatter in axis ratio, extending above and below equilibrium, was found for the largest sizes (d = 1.40–1.54 mm) with the average axis ratio being larger than equilibrium. All but the smallest drops displayed a sideways drift varying from 1% of the terminal velocity for d = 0.82–1.0...