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Model of compactons on jet streams and their collapse
1Institute of Atmospheric Physics, Russian Academy of Sciences, 109017 Moscow, Russia. v.goncharov@mtu-net.ru
Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics
|February 1, 2008
Summary
This study introduces compactons, stable vortex structures in decaying jet streams. These structures intensify at their boundaries as they collapse.
Area of Science:
- Fluid dynamics
- Plasma physics
- Mathematical physics
Background:
- Vortex dynamics in fluid systems are complex.
- Understanding jet stream decay is crucial for predicting phenomena like turbulence and structural collapse.
- Previous models often struggle to capture the behavior of strongly perturbed jet streams.
Purpose of the Study:
- To develop a Hamiltonian formulation of contour dynamics for axially symmetric jet streams.
- To investigate the emergence and behavior of dominant structural elements during jet stream decay.
- To analyze the properties and collapse mechanisms of structures termed 'compactons'.
Main Methods:
- Formulation of the Hamiltonian version of contour dynamics.
- Modeling of axially symmetric, equally vortexed jet streams with a free boundary.
- Analysis of solutions with compact support, identified as compactons.
Main Results:
- The model successfully generates compacton solutions, representing dominant structures in decaying jet streams.
- Compacton evolution leads to a collapse that preserves shape but intensifies the boundary vortex sheet.
- The intensification follows a specific power-law dependence on the time to collapse: (t(0)-t)^-1.
Conclusions:
- Compactons are key structural elements in the decay of perturbed jet streams.
- The Hamiltonian contour dynamics model provides a framework for studying these phenomena.
- The observed collapse mechanism offers insights into the intensification of vortex sheets at free boundaries.
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