The effect of weak axisymmetric magnetic and/or electrostatic perturbations on the equilibrium of a non-neutral plasma in a Malmberg-Penning trap is analyzed. Analytical and semianalytical solutions for the potential variations inside the trap are found in a paraxial limit of the perturbations for various radial density profiles of the plasma, including the case of global thermal equilibrium. I...

We report on the first three-dimensional hydrodynamic simulations of secular and dynamical nonaxisymmetric instabilities in collapsing, rapidly rotating stellar cores which extend well beyond core bounce. The resulting gravitational radiation has been calculated using the quadrupole approximation. We find that secular instabilities do not occur during the simulated time interval of several 10ms...

In order to research the influence of the contamination around the external insulating surface of DC voltage divider with different types in the electic field distribution by using the finite element method, a two dimensional axisymmetric model of the DC voltage divider in Longquan convertor station is built. Through the calculation comparison in electrostatic and quasi-electrostatic field, the...

Stability of core-annular flow of water and oil in a vertical circular pipe is studied with respect to nonaxisymmetric disturbances. Results show that when the oil core is thin, the flow is most unstable to the asymmetric sinuous mode of disturbance, and the core moves in the form of corkscrew waves as observed in experiments. The asymmetric mode of disturbance is the most dangerous mode for qu...

This short paper describes a numerical model study of an axisymmetric atmospheric circulation (somewhat akin to the Earth’s tropical Hadley circulation) subject to a periodic forcing that cyclically modifies the static stability. The configuration is not particularly realistic as a representation of the true circulation in the Earth’s tropics, but its motivation is justified as an idealized tes...

Axisymmetric pulsations of rotating neutron stars can be excited in several scenarios, such as core-collapse, crust and core-quakes and binary mergers and could become detectable either in gravitational waves or high-energy radiation. Here, we present a comprehensive study of all low-order axisymmetric modes of uniformly and rapidly rotating relativistic stars. Initial stationary configurations...

We develop in this paper a numerical method to simulate three-dimensional incompressible flows based on a decomposition of the flow into an axisymmetric part, in terms of the stream function and the circulation, and a non-axisymmetric part in terms of a potential vector function. The method is specially suited for the study of nonlinear stability of axially symmetric flows because one may follo...

simulation of rough rice drying is one of the proper methods for predicting moisture distribution in the product, and throughout the process of drying. the drying process must be well understood and controlled so that design guidelines which reduce or minimize drying damage to rough rice can be established and improved. therefore, an accurate understanding and description of the drying mechanis...