Self-organization of two-dimensional incompressible viscous flow in a friction-free box

摘要

The process by which self-organization occurs for two-dimensional incompressible viscous flow in a friction-free box is investigated theoretically with the use of numerical simulations. It is shown by an eigenfunction spectrum analysis that two basic processes for the self-organization are the spectrum transfer by nonlinear couplings and the selective dissipation among the eigenmodes of the dissipative operator, and they yield spectrum accumulation at the lowest eigenmode. It is also clarified that an important process during nonlinear self-organization is an interchange between the dominant operators, which leads to a final self-similar coherent structure, determined uniquely by the lowest eigenmode of the dissipative operator. (author).