Impact of emulsion drops on a plane solid: Effect of composition and wall temperature
Impact of emulsion drops on a plane solid: Effect of composition and wall temperature
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DOI：
10.1007/s00231-021-03129-3
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发表时间：
2021-09
影响因子：
2.2
通讯作者：
Amrit Kumar;D. K. Mandal
中科院分区：
文献类型：
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作者：
Amrit Kumar;D. K. Mandal
本文报道了麻疯树生物柴油乳剂中的水对加热固体表面的影响。研究了表面温度（TS）和乳液组成对冲击动力学的影响。采用三种低含水量乳剂样品，在五种表面温度下进行了实验，并将实验结果与现有文献中纯麻疯树生物柴油（JBD）进行了比较。由于乳状液滴内水分微滴的早期蒸发，形成内部蒸汽压。内部蒸汽压和由于高汽化速率而在液滴下形成的薄气膜对乳剂的影响起着至关重要的作用。与JBD相比，乳化导致莱顿弗罗斯特温度降低，影响粘滞和弹跳行为。归一化平均扩散速度和平均后退速度随TS的增大而增大，且与JBD相比，在较高的TS条件下，它们的最大值最大。与JBD相比，在乳状液的冲击形态上观察到一些差异。内蒸汽压克服了高温度下乳剂的粘性耗散，使得乳剂的最大扩散系数和扩散速度高于JBD。
The paper reports the impact of water-in-Jatropha biodiesel emulsion drops on a heated solid surface. The role of the surface temperature (TS) and the composition of the emulsion on the impact dynamics are examined. Experiments are conducted taking three low water content emulsions samples for five surface temperatures, and the results are compared with pure Jatropha biodiesel (JBD) from the available literature. Due to the early evaporation of water micro-droplets inside the emulsion drop, internal vapor pressure is formed. The internal vapor pressure and the thin vapor film formed beneath the drop due to the high vaporization rate play a crucial role in the impact of emulsions. Emulsification results in a decrease in the Leidenfrost temperature when compared with JBD, affecting the sticking and bouncing behavior. The normalized average spreading velocity and the average receding velocity increase with TS, and their maxima are found at higher TSin case of emulsions as compared to JBD. Several differences are observed in the impact morphology of the emulsions when compared to JBD. The internal vapor pressure overcomes the viscous dissipation for the emulsions at higher TSresulting in a higher maximum spreading factor and spreading velocity than JBD.