arXiv subjects
Publications and source records attributed to Hideki Takayasu.
Simulations of vortex tube dynamics reveal that the non-Gaussian nature of turbulent fluctuation originates in the effect of random advection. A similar non-Gaussian distribution is found numerically in a simplified statistical model of random advection. An analytical solution is obtained in the mean-field case.
Fully developed turbulence is analised with the lattice model employing vortex tube representation which is introduced recently by the authors. Several characteric features observed in experiments and direct numeric integrations are reproduced. Not only Kolmogorov's inertial range is observed, but also several local probability distribution functions are obtained as well. Those of the local velocities are close to the Gaussian and exponential-like distributions appear in local vorticity, relative velocities and local velocity consisting of only higher wave number components. Coherent structure of vortex tubes is seen, too. Moreover required cpu-time and memory-size are very little comparing with the conventional pseudo-spectral method. keywords : fluid turbulence, vortex tube, lattice model, numerical technic.