Repozytorium publikacji - Politechnika Gdańska

The characteristics of propagation of sawtooth periodic and impulsive signals at a transducer are analytically studied in this work. A plasma under consideration is motionless and uniform at equilibrium, and its perturbations are described by a system of ideal magnetohydrodynamic equations. Some generic heating/cooling function, which in turn depends on equilibrium thermodynamic parameters, may destroy adiabaticity of a flow and make the flow acoustically active. Planar waves with the wave vector forming a constant angle θ with the equilibrium straight magnetic strength are considered. This model has been proposed in previous publications listed in the Introduction. Conclusions are drawn for fast and slow magnetoacoustic waves of sawtooth shape and various cases of a nonlinear flow. These nonlinearities occur in accordance with a type of heating/cooling function under consideration. Amplitude and duration of signals are evaluated as functions of a distance from a transducer, θ, plasma-β, and a type of heating-cooling function. In particular, it is observed that the duration of an impulse enlarges infinitely in acoustically stable flows, while on the other hand, it tends to some limiting value in acoustically active flows of plasma.

Autorzy

• prof. dr hab. Anna Perelomova link otwiera się w nowej karcie