This article describes the effect of whirlpool electrical currents generated in metal wall for wiring and upper and lower reinforcement rings ofelectricd- ynamic vibrator armature upon the performance of the vibrator, several practical methods with their associated brief theory are given to eliminate or reduce bad effects of these whirlpool electrical currents.

The result showed that this hail event belong to the type of northwest cold eddy influence which has its own characteristic opposite to hail of northwest air curr.

Rigid trailing vortex model consistent with Goldstein hypothesis is often employed in propelles lifting line (lift surface) calculation on the condition of light load,but presents certain errors on the condition of heavy load.

And ensemble average was made in order to find the spatial evolution of the propeller wake,including tip vortex and trailing vortex sheet,in the region from the training edge to 2.

The evolutionary process of trailing vortex structure was analyzed.

In order to augment run-way capacity while maintaining safety,wake vortex separation can be reduced based on dynamic prediction of its dissipation.

The wake vortex patterns,the distributions and the time series of dispersion functions of particles with different Stokes numbers were obtained.

The large eddy simulation methods can be used to analysis and calculate the decay and transport rules of wake vortex in near ground phases,but it′s too complex and difficult to use.