Path-integrated Lagrangian measures from the velocity gradient tensor
Path-integrated Lagrangian measures from the velocity gradient tensor
复制标题
来自速度梯度张量的路径积分拉格朗日测量
DOI：
--
复制
发表时间：
2013
期刊：
影响因子：
--
通讯作者：
F. Huhn
中科院分区：
文献类型：
--
作者：
V. Pérez‐Muñuzuri;F. Huhn
抽象的。有限时间李雅普诺夫指数（FTLE）的空间映射已被广泛用于研究二维动力系统中的LCS，特别是应用于非定常流体流动中的输运。我们使用时间周期的双涡旋模型的FTLE和路径集成的欧拉Okubo-Weiss参数（OW）的空间场进行比较。这两个领域的相关性很强，并通过解决变形梯度张量的动力学，两个幅度之间的理论关系已经获得。虽然对于长的集成时间越来越多的FTLE脊出现，似乎不符合稳定的流形，脊在该领域的路径集成OW代表较少的额外的结构。
Abstract. Spatial maps of the finite-time Lyapunov exponent (FTLE) have been used extensively to study LCS in two-dimensional dynamical systems, in particular with application to transport in unsteady fluid flows. We use the time-periodic double-gyre model to compare spatial fields of FTLE and the path-integrated Eulerian Okubo–Weiss parameter (OW). Both fields correlate strongly, and by solving the dynamics of the deformation gradient tensor, a theoretical relationship between both magnitudes has been obtained. While for long integration times more and more FTLE ridges appear that do not seem to coincide with the stable manifold, ridges in the field of path-integrated OW represent fewer additional structures.