Numerical simulations of shocks encountering clumpy regions Simulations of shocks encountering clumpy regions
Numerical simulations of shocks encountering clumpy regions Simulations of shocks encountering clumpy regions
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遇到块状区域的冲击的数值模拟 遇到块状区域的冲击的数值模拟
DOI：
10.1111/j.1365-2966.2012.21598.x
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发表时间：
2012
影响因子：
4.8
通讯作者：
Aluzas R
中科院分区：
文献类型：
--
作者：
Aluzas R
本文对激波与包含许多单个云团的云团区的绝热相互作用进行了数值模拟。我们的工作采用了亚网格湍流模型，这是第一次使这项调查可行。我们改变激波的马赫数，云的密度对比度和总的云质量的比云间质量的cloudspeaker区域。云的物质被并入气流中。这种“质量加载”降低了激波的马赫数，并导致致密壳体的形成。在质量载荷足够大的情况下，流动减慢到足以使激波退化为波。相互作用的发展经历了四个阶段：最初激波减速;然后它的速度几乎是恒定的;接下来激波在离开云团区时加速;最后，它以接近其初始速度的恒定速度移动。当激波扫过团簇区时，激波后流中产生湍流。暴露在湍流中的云可以比“孤立”环境中的类似云更快地被破坏。下游云的寿命随云间质量比的增加而减小。我们简要地讨论了这些结果的意义，星暴超级风和星系演化。
We present numerical simulations of the adiabatic interaction of a shock with a clumpy region containing many individual clouds. Our work incorporates a sub-grid turbulence model which for the first time makes this investigation feasible. We vary the Mach number of the shock, the density contrast of the clouds and the ratio of total cloud mass to intercloud mass within the clumpy region. Cloud material becomes incorporated into the flow. This ‘mass loading’ reduces the Mach number of the shock and leads to the formation of a dense shell. In cases in which the mass loading is sufficient the flow slows enough that the shock degenerates into a wave. The interaction evolves through up to four stages: initially the shock decelerates; then its speed is nearly constant; next the shock accelerates as it leaves the clumpy region; finally, it moves at a constant speed close to its initial speed. Turbulence is generated in the post-shock flow as the shock sweeps through the clumpy region. Clouds exposed to turbulence can be destroyed more rapidly than a similar cloud in an ‘isolated’ environment. The lifetime of a downstream cloud decreases with increasing cloud-to-intercloud mass ratio. We briefly discuss the significance of these results for starburst superwinds and galaxy evolution.