涡电流[Eddy Current] - 达人(其实～我是卧底，来自外星)

2005/05/05 | 涡电流[Eddy Current]
类别(Ω〖物理〗) | 评论(0) | 阅读(40) | 发表于 12:38: An eddy current is a residual current which flows after time-varying electric E and magnetic fields B are removed. In cgs,
(1)

(2)

(3)

for slowly varying fields, where c is the speed of light, J is the current density, and is the conductivity. Combining (2) and (3) gives
(4)

(5)

which is a diffusion equation with diffusion coefficient
(6)

The diffusion time for decay of the eddy current is therefore
(7)

where L is the length scale.; 0