@article{oai:nagoya.repo.nii.ac.jp:02003785, author = {Yoshimatsu, Katsunori and Kaneda, Yukio}, issue = {5}, journal = {Journal of the Physical Society of Japan}, month = {May}, note = {We study the free decay of incompressible homogeneous nonaxisymmetric turbulence with and without helicity, by using direct numerical simulations (DNSs). Its initial energy spectrum E(k), say at t = t0, is given by Ck2 + o(k2) in a sufficiently low k-range, where k is the wavenumber, and C is a positive constant independent of k. We focus our attention to turbulence whose anisotropy is generated by the action of simple mean shear, and consider the decay after the sudden release of the mean shear. The DNSs suggest that at a stage where the turbulence evolves in a self-similar way, the large-scale anisotropy characterized by statistical quantities including the relative velocity correlations is persistent, irrespective of the presence or absence of the initial helicity. The DNSs also suggest that E(k) keeps the form Ck2 + o(k2) at low k for t ≥ t0, and C is time-independent. These DNS results are in accordance with those by a theory about a generalization of a turbulence class of what was argued by Saffman [J. Fluid Mech. 27, 581 (1967)].}, title = {Dynamical Invariance and Self-Similarity of Freely Decaying Homogeneous Nonaxisymmetric Turbulence}, volume = {91}, year = {2022} }