Abstract The impingement dynamics of a promising ionic liquid absorbent, namely, 1-ethyl-3-methylimidazolium acetate ([EMIm]Ac) in droplet falling film flow modes on heated porous surfaces in absorption refrigeration were investigated experimentally. The influences of impact velocity and surface temperature on the ionic liquid droplet spreading diameter, dynamic contact angle, spreading height, and residual volume against the heated porous surfaces were explored. The results indicated that the residual volume generally decreased in linear with increasing contact time at 323.15 K, while the dependence exhibited a polynomial behavior at higher heating temperatures. Compared to the impingement behaviors of deionized water droplets, such as oscillations and capillary waves were not observed in [EMIm]Ac droplets. The residual volume of the deionized water droplets varied exponentially with the contact time owing to the combined effects of the evaporation, penetration, and variation of the thermophysical properties of the droplet. Moreover, increases in the impact velocity and surface temperature enlarge the spreading diameter and accelerate the droplet penetration for the ionic liquid.

中文翻译：

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[EMIm]Ac离子液滴在加热多孔表面上的冲击动力学

摘要 通过实验研究了一种有前途的离子液体吸收剂，即 1-乙基-3-甲基咪唑乙酸盐 ([EMIm]Ac) 在吸收式制冷加热多孔表面上的液滴降膜流动模式下的冲击动力学。探讨了冲击速度和表面温度对离子液滴扩散直径、动态接触角、扩散高度和对加热多孔表面的残留体积的影响。结果表明，在 323.15 K 时，残余体积通常随着接触时间的增加呈线性下降，而这种依赖性在较高的加热温度下表现出多项式行为。与去离子水滴的撞击行为相比，在[EMIm]Ac 水滴中没有观察到振荡和毛细波等。由于蒸发、渗透和液滴热物理性质变化的综合影响，去离子水液滴的残留体积随接触时间呈指数变化。此外，冲击速度和表面温度的增加扩大了扩散直径并加速了离子液体的液滴渗透。