论文标题
塌陷气云中湍流的饱和水平
Saturation level of turbulence in collapsing gas clouds
论文作者
论文摘要
我们研究了决定崩溃的气云中湍流饱和水平的物理机制。在用各种有效的多质指数$γ_ {\ rm eff} $，初始马赫数$ \ MATHCAL {M} _0 $和初始湍流种子和初始湍流种子的情况下，我们执行了一组高分辨率数值模拟的套件。通过重力收缩和湍流的耗散速率等于能量注射速率，我们获得了湍流饱和水平的分析表达，并将其与数值结果进行比较。因此，分析模型很好地描述了数值结果，鉴于气云中的湍流驱动量表是折叠核心牛仔裤长度的三分之一。这些结果表明，在早期宇宙/当今恒星形成过程中，第一个核心形成的湍流强度只能通过$γ_ {\ rm eff} $估算。
We investigate the physical mechanism that decides the saturation level of turbulence in collapsing gas clouds. We perform a suite of high-resolution numerical simulations following the collapse of turbulent gas clouds with various effective polytropic exponents $γ_{\rm eff}$, initial Mach numbers $\mathcal{M}_0$, and initial turbulent seeds. Equating the energy injection rate by gravitational contraction and the dissipation rate of turbulence, we obtain an analytic expression of the saturation level of turbulence, and compare it with the numerical results. Consequently, the numerical results are well described by the analytic model, given that the turbulent driving scale in collapsing gas clouds is one-third of Jeans length of collapsing core. These results indicate that the strength of turbulence at the first core formation in the early universe/present-day star-formation process can be estimated solely by $γ_{\rm eff}$.
