论文标题
均质各向同性湍流中分布式核燃烧中的普遍性和非统一性
Universality and Non-Universality in Distributed Nuclear Burning in Homogeneous Isotropic Turbulence
论文作者
论文摘要
核燃烧在广泛的天体物理恒星瞬变中起着关键作用，包括热核，配对不稳定性和核心塌陷超新星，以及Kilonovae和Collapsars。现在认为湍流在这些天体物理瞬变中也起着关键作用。在这里，我们证明湍流的核燃烧可能会导致高于均匀背景燃烧速率的大大增强，因为湍流耗散会导致温度波动，并且通常，核燃烧速率对温度高度敏感。我们使用概率分布函数（PDF）方法得出了在均质各向同性湍流中分布的燃烧状态中强湍流影响下核燃烧速率湍流的结果。我们证明，湍流增强在弱湍流的极限下服从了普遍的缩放定律。我们进一步证明，对于各种关键的核反应，例如c $^{12} $（o $^{16} $，$α$）mg $^{24} $和三重$α$，甚至相对较小的温度波动，也可能导致1-3个级别的大量增强型在1-3个级别的构成大量的型号的型号。我们直接针对数值模拟验证了预测的湍流增强，并找到了很好的一致性。我们还提出了湍流爆炸开始的估计，并讨论了我们结果对恒星瞬变建模的含义。
Nuclear burning plays a key role in a wide range of astrophysical stellar transients, including thermonuclear, pair instability, and core collapse supernovae, as well as kilonovae and collapsars. Turbulence is now understood to also play a key role in these astrophysical transients. Here we demonstrate that turbulent nuclear burning may lead to large enhancements above the uniform background burning rate, since turbulent dissipation gives rise to temperature fluctuations, and in general the nuclear burning rates are highly sensitive to temperature. We derive results for the turbulent enhancement of the nuclear burning rate under the influence of strong turbulence in the distributed burning regime in homogeneous isotropic turbulence, using probability distribution function (PDF) methods. We demonstrate that the turbulent enhancement obeys a universal scaling law in the limit of weak turbulence. We further demonstrate that, for a wide range of key nuclear reactions, such as C$^{12}$(O$^{16}$, $α$)Mg$^{24}$ and triple-$α$, even relatively modest temperature fluctuations, of the order ten percent, can lead to enhancements of 1 - 3 orders of magnitude in the turbulent nuclear burning rate. We verify the predicted turbulent enhancement directly against numerical simulations, and find very good agreement. We also present an estimation for the onset of turbulent detonation initiation, and discuss implications of our results for the modeling of stellar transients.
