Formation of a gas condensation in a perturbed shock
Formation of a gas condensation in a perturbed shock
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扰动激波中气体凝结的形成
DOI：
10.1093/mnras/234.1.51
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发表时间：
1988
影响因子：
4.8
通讯作者：
M. Tosa
中科院分区：
文献类型：
--
作者：
Toshiya Kimura;M. Tosa
本文采用二维流体动力学方法模拟了扰动激波后压缩气体中气体凝聚的形成过程，将准定常的平面驻激波视为未扰动状态，并对该状态施加扰动，使激波前发生轻微的变形和位移.数值模拟了气流对扰动的响应，特别注意了激波阵面后气体凝结的形成，结果表明，当气流通过扰动激波阵面的倾斜部分时，流线发生偏转，从而接近激波阵面，而激波锋面后面的压缩气体流向扭曲锋面的底部并在那里积聚形成气体凝结。在本数值例子中，在扰动激波阵面后形成的气体凝聚体，其气体密度约为激波压缩气体平均密度的1.5倍，这一现象解释了激波压缩区分子云的块状结构，并在激波触发恒星形成过程中起重要作用.
Results of two-dimensional hydrodynamical simulations are presented of formation of gas condensations in the compressed gas behind a disturbed shock front.A plane standing shock wave in a quasi-steady state is considered as an unperturbed state, and a perturbation is applied to this state that slightly distorts and displaces the shock front from the unperturbed position. The responses of the gas flow to the perturbation are followed numerically with special attention to formation of gas condensations behind the shock front.The results show that as the gas passes through oblique parts of the perturbed shock front, the stream lines are deflected so as to approach the shock front, and the compressed gas behind the shock front flows towards the bottom of the distorted front and accumulates there to form a gas condensation.In the present numerical example, a gas condensation with a gas density about 1.5 times as high as the average density of the shock compressed gas is created.The formation of gas condensations behind a disturbed shock front naturally explains observed clumpiness of shock-compressed regions of molecular gas clouds and would play an important role in formation of stars triggered by shock waves.