It can be concluded that the effect of vortex shedding is predominant in the excited instability of a TTR under combined excitation when the outside sea state is mild, but when the sea states is severe, parametric excitation contributes more to the instability, vortex-shedding excitation only strengthens the consequent instability.
Parametrically excited instability in a cantilevered column, under a periodic load in the direction of the tangency coefficient at its free end, was investigated analytically.
This paper is concerned with parametrically excited instabilities in a lightly damped gyroscopic compass under the influence of a harmonic vertical acceleration of the suspension point.
The excitation is periodic, and it can excite instability.
This governs the growth rates of the natural acoustic modes, determined by system geometry, boundary conditions and mean temperature distribution, which are excited into instability by unsteady heat release from the flame and damped by large scale vorticity production and radiation losses into the environment.
As for electrodynamic perturbations to become seeds of an instability process, numerical simulation by Yokoyama (2013) has shown that random electrodynamic perturbations without specific scale size will excite an instability process in the mid-latitude E-F region to result in medium-scale traveling disturbances with a size of 100 to 200 km.
However, since the system is inherently unstable, any deviation from that model in particular, any unanticipated external disturbances will excite the instability.
In all, to our knowledge, the ESWs can be generated through some kind of mechanism such as the bump-on-tail instability or two-stream instability excited by the electron beam which is generated in the MR process.
The small-scale fluctuations on the kinetic scales (at wavenumbers higher than that of the ion inertial length) cannot be excited by linear instability processes - neither micro-instability caused by gradients in the velocity coordinate nor macro-instability caused by gradients in the spatial coordinate.
However, via acoustic disturbances, the boundary-layer instability may become more significant, through the resonance with the wake instability, excited by increasing a base-flow Mach number.
A PCP user is often impervious to pain and generally exhibits emotional instability, excited intoxication, a lack of coordination, high blood pressure, and increased deep-tendon muscle reflexes.
