Simulation of coherent structures (topological solitons) inside closed rooms by solving numerically hydrodynamic equations
V.V. Nosov, V.P. Lukin, E.V. Nosov, A.V. Torgaev
V.E. Zuev Institute of Atmospheric Optics of Siberian Branch of the Russian Academy of Science, 1, Academician Zuev square, Tomsk, 634021, Russia
Keywords: turbulence, coherent turbulence, coherent structure, topological soliton, simulation of coherent structures, hydrodynamics equations, Navier-Stokes equations, topological precursor
Subsection: OPTICAL WAVE PROPAGATION
Abstract
Coherent structures (three-dimensional topological solitons) inside closed rooms had been simulated by solving numerically hydrodynamic equations (Navier–Stokes equations). A closed room is a volume without the exchange of internal and external medium through the borders. Results of eight boundary value problems are given: spectrograph pavilion and telescope dome of large astronomical telescopes (LSVT and BTA), cubic room, flat square cuvette, square section tube, parietal turbulence (thermals), dome (hemisphere with a viscous medium), and open space above one heated spot. Solitary large vortices (coherent structures or topological solitons) are observed inside the volume. The patterns of air motion as a result of simulation of coherent structures with identical boundary conditions are practically the same as the patterns, independently recorded earlier in our experiments (indoors LSVT and BTA). Also inside other volumes the patterns of medium motion as a result of simulation of coherent structures are practically the same as the patterns, previously recorded at experiments by other authors. Simulations confirm the previously formulated experimental conclusion that mixing of many coherent structures with different close sizes (and with close frequencies of main vortices) gives non-coherent Kolmogorov turbulence. In addition, relatively long inertial intervals of spectrum with Kolmogorov 5/3-exponential decay are observed in highly viscous media.
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