论文标题
全球动量保护对纵向流动的影响
Effect of global momentum conservation on longitudinal flow decorrelation
论文作者
论文摘要
储层计算是预测湍流的有力工具，其简单的架构具有处理大型系统的计算效率。然而，其实现通常需要完整的状态向量测量和系统非线性知识。我们使用非线性投影函数将系统测量扩展到高维空间，然后将其输入到储层中以获得预测。我们展示了这种储层计算网络在时空混沌系统上的应用，该系统模拟了湍流的若干特征。我们表明，使用径向基函数作为非线性投影器，即使只有部分观测并且不知道控制方程，也能稳健地捕捉复杂的系统非线性。最后，我们表明，当测量稀疏、不完整且带有噪声，甚至控制方程变得不准确时，我们的网络仍然可以产生相当准确的预测，从而为实际湍流系统的无模型预测铺平了道路。
We calculate the longitudinal flow decorrelation coefficients, i.e., $r_n(η,η_r)$ for $n=2,3$, in the presence of hydro-like flow and the global momentum conservation (GMC) constraint. The longitudinal flow decorrelation is weakened due to the GMC constraint. The GMC effect is sensitive to the total number of particles involved in GMC, the average longitudinal momentum, the transverse momentum, and the reference pseudorapidity. Our results of the $r_2(η,η_{rA})/r_2(η,η_{rB})$ ratio between two reference pseudorapidity bins are consistent with the experimental measurements. We predict that the modification effect of GMC on longitudinal flow decorrelation is more noticeable at BNL Relativistic Heavy Ion Collider energies than at CERN Large Hadron Collider energies. Our finding provides a new perspective for understanding the longitudinal flow decorrelation in relativistic heavy-ion collisions.
