论文标题

圆形液压跳跃表面张力起源的实验证据

Experimental evidence for surface tension origin of the circular hydraulic jump

论文作者

Bhagat, Rajesh K., Wilson, D. Ian, Linden, P. F.

论文摘要

一个多世纪以来,共识一直是在厨房水槽中可以看到的薄膜液压跳是由重力产生的。但是,我们最近报告说,这些跳跃是通过表面张力产生的,重力不起作用。在本文中,{我们介绍了在微实力环境中进行的液压跳跃实验的实验数据(地球重力的约2 \%$)(Avedisian \&Zhao 2000; Painter etal。2007; Phillips etal。2008)。微实力中的液压跳跃的存在无明确地证实,重力并不是导致厨房水槽液压跳跃形成的主要力量。}我们还提供了13套实验数据,在文献中,在文献中报告了在稳态的文献中,用于与不同物理物理型的稳态型和实验率的稳定型的稳态。与{Bhagat等人}的理论预测有很好的一致性。我们还表明,超出临界流量,$ q_c^* \ proptoγ^2 /νρ^2 g $,重力确实会影响液压跳跃。在较低的流速下,在厨房水槽的规模下,表面张力是主导力。我们讨论了先前报道的液压跳跃的现象学和预测模型,并表明现象学模型有效地说明了整个跳跃的径向动量的连续性 - 不允许识别跳跃起源的机制。但是,结合现象学模型和{Bhagat等人}的理论使我们能够预测跳跃的高度。

For more than a century, the consensus has been that the thin-film hydraulic jump that can be seen in kitchen sinks is created by gravity. However, we recently reported that these jumps are created by surface tension, and gravity does not play a significant role. In this paper, {we present experimental data for hydraulic jump experiments conducted in a micro-gravity environment ($\approx 2\%$ of Earth's gravity) (Avedisian \& Zhao 2000; Painter et al. 2007; Phillips et al. 2008). The existence of a hydraulic jump in micro-gravity unequivocally confirms that gravity is not the principal force causing the formation of the kitchen sink hydraulic jump.} We also present thirteen sets of experimental data conducted under terrestrial gravity reported in the literature for jumps in the steady-state for a range of liquids with different physical parameters, flow rates and experimental conditions. There is good agreement with {Bhagat et al.}'s theoretical predictions. We also show that beyond a critical flow rate, $Q_C^* \propto γ^2 /νρ^2 g$, gravity does influence the hydraulic jumps. At lower flow rates, at the scale of the kitchen sink, surface tension is the dominating force. We discuss previously reported phenomenological and predictive models of hydraulic jumps and show that the phenomenological model -- effectively a statement of continuity of radial momentum across the jump -- does not allow the mechanism of the origin of the jump to be identified. However, combining the phenomenological model and {Bhagat et al.}'s theory allows us to predict the height of the jump.

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