Short-time evolution of Lagrangian velocity gradient correlations in isotropic turbulence

@article{Fang2015ShorttimeEO,
  title={Short-time evolution of Lagrangian velocity gradient correlations in isotropic turbulence},
  author={L. Fang and Wouter J. T. Bos and G. D. Jin},
  journal={Physics of Fluids},
  year={2015},
  volume={27},
  pages={125102}
}
We show by direct numerical simulation (DNS) that the Lagrangian cross correlation of velocity gradients in homogeneous isotropic turbulence increases at short times, whereas its auto-correlation decreases. Kinematic considerations allow to show that two invariants of the turbulent velocity field determine the short-time velocity gradient correlations. In order to get a more intuitive understanding of the dynamics for longer times, heuristic models are proposed involving the combined action of… 
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