Freely decaying turbulence in 2D Re_l=1250

The initial conditions were chosen similarly to those of the physical experiment described in the work of P. Tabeling (2002) for a regular configuration with 64 vortices. These were cast in an array of 8 × 8 Taylor–Green vortices in a bi-periodic domain with size L × L (the reference length L is set equal to 1). The maximum value of the velocity field in the initial configuration is U = 1. The Reynolds number was Re_l = lU/ν = 1250, with l = L/8 the vortex size. For details see: A. Di Mascio, M. Antuono, A. Colagrossi, and S. Marrone, Smoothed particle hydrodynamics method from a large eddy simulation perspective​ , Physics of Fluids, Volume 29, 035102, (2017). The video shows the Finite Lyapunov Exponents For details see: P.N. Sun, A. Colagrossi, S. Marrone, A.M. Zhang, ​ Detection of Lagrangian Coherent Structures in the SPH framework, ​ Computer Methods in Applied Mechanics and Engineering, Applied Mechanics and Engineering, ​ 305​ , 849-868, (20