Physical parameters governing the formation of Pele's hair and tears
Physical parameters governing the formation of Pele's hair and tears
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控制贝利头发和眼泪形成的物理参数
DOI：
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发表时间：
1994
期刊：
影响因子：
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通讯作者：
D. Shimozuru
中科院分区：
文献类型：
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作者：
D. Shimozuru
讨论了在岩浆喷射过程中影响贝利毛发和贝利泪形成的物理参数。对喷嘴在不同韦伯数（We）和雷诺数（Re）下产生的喷墨进行了实验，结果表明：如果（Re）相对于（We）较大，则会产生墨滴。然而，如果（Re）相对较小，（We）较大，则喷射墨水变成线状。我定义Pele数（Pe）为(We)/(Re)，表示为ρvη/ρ0σ，其中v为喷口喷出的速度，η和σ为喷发岩浆的粘度和界面张力，ρ和ρ0为空气和岩浆的密度。喷墨的实验结果表明，贝利的头发会被打印成较大的（Pe），而贝利的眼泪很可能被打印成相对较小的（Pe）。我的结论是，贝利的头发可能是在岩浆喷发速度高的时候产生的，而贝利的眼泪可能是在岩浆喷发速度相对低的时候产生的。作为一个额外的兴趣点，贝利头发特征形状的SEM照片与商业玻璃纤维失败产品的相似之处被显示出来。
The physical parameters that affect the formation of Pele's hair and Pele's tears during lava fountaining are discussed. Experiments on ink jets produced from a nozzle under different Weber number (We) and Reynolds number (Re) show the following results: if (Re) is relatively large compared with (We), an ink droplet is produced. However, if (Re) is relatively small and (We) is large, the spurting ink becomes thread-like. I define the Pele number (Pe) as (We)/(Re), which is expressed as ρvη/ρ0σ, where v is the spuring velocity from an erupting vent, η and σ are viscosity and interfacial tension of the erupting magma, and ρ and ρ0 are density of air and magma. The experimental results from ink jets suggest that Pele's hair will be produced for larger (Pe), while Pele's tears are very likely produced for relatively small (Pe). I conclude that Pele's hair could be produced when the spurting velocity of erupting magmas is high, and Pele's tears when it is relatively low. As an additional point of interest, the similarity of SEM photographs of the characteristic shape of Pele's hair to those of the failed products of commercial glass fibre are shown.