Numerical simulation of the nonlinear dynamics of packets of spiral density waves

Journal Article · Thu Jan 01 04:00:00 EST 1987 · Astrophysics (Engl. Transl.); (United States)

DOI:https://doi.org/10.1007/BF01006678· OSTI ID:6606682

Korchagin, V I

In a numerical experiment, the behavior of nonlinear packets of spiral density waves in a gas disk has been investigated for different initial wave amplitudes. If the amplitude of the density perturbations is small (<5%), the wave packet is drawn toward the center or toward the periphery of the disk in accordance with the linear theory. The behavior of linear packets of waves with wavelength comparable to the disk radius (R/sub d//lambda = 4) exhibits good agreement with the conclusions of the linear theory of tightly wound spiral waves. The dynamics of wave packets with initial density amplitudes 16, 30, 50% demonstrates the nonlinear nature of the behavior. THe behavior is governed by whether or not the nonlinear effects of higher than third order in the wave amplitude play a part. If the wave packet dynamics is determined by the cubic nonlinearity, the results of the numerical experiment are in qualitative and quantitative agreement with the nonlinear theory of short waves, although the characteristic scale of the packet and the wavelength are of the order of the disk radius. In the cases when the nonlinear effects of higher orders in the amplitude play an important part, the behavior of a packet does not differ qualitatively from the behavior predicted by the theory of cubic nonlinearity, but the nonlinear spreading of the packet takes place more rapidly.

• Research Organization: Rostov State Univ., USSR
• OSTI ID: 6606682
• Journal Information: Astrophysics (Engl. Transl.); (United States), Journal Name: Astrophysics (Engl. Transl.); (United States) Vol. 25:1; ISSN ATPYA
• Country of Publication: United States
• Language: English

Related Subjects

640105* -- Astrophysics &amp; Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AMPLITUDES
CONFIGURATION
COSMIC GASES
DENSITY
FLUID MECHANICS
FLUIDS
GALAXIES
GASES
GRAVITATIONAL FIELDS
HYDRODYNAMICS
MECHANICS
NONLINEAR PROBLEMS
PERTURBATION THEORY
PHYSICAL PROPERTIES
PLASMA SIMULATION
PLASMA WAVES
SIMULATION
SPACE-TIME
SPIRAL CONFIGURATION
WAVE PACKETS
WAVE PROPAGATION