7.6 Three-dimensional modeling and simulations Ë 241Fig. 7.16:Geometrical modeling of the 3D simulation of
the HTS Maglev system.described in Fig. 7.16. The virtual conductivity of the HTSC is calculated by
1
휎sc=|Esc|
|Jsc|, (7.51)
whereEscandJscare the electric field and current density of the HTSC, respectively.
According to theE-Jexponent power law (see Eq. 7.14), the expression to calculate the
conductivity is
1
휎sc=|Esc|
|Jsc|=Ec0
Jc|Jsc|
Jc
n− 1. (7.52)
Based on Ampère’s law [see Eq. (7.1)], we have
Jsc,xx̂+Jsc,yŷ+Jsc,zẑ=¤휕Hz
휕y−
휕Hy
휕Hz−
휕Hy
휕Hz¥x̂+휕Hx
휕z−휕Hz
휕xŷ+¤
휕Hy
휕x−휕Hx
휕y¥ẑ. (7.53)Therefore, the three components of the supercurrent can be expressed in terms of the
magnetic field as follows:
. (^66)
(^666)
(^66)
(^66)
(^666)
(^66)
F
Jsc,x=
휕Hz
휕y −
휕Hy
휕z,
Jsc,y=휕Hx
휕z
−휕Hz
휕x
,
Jsc,z=휕Hy
휕x−휕Hx
휕y.
(7.54)
The anisotropic feature of the critical current density in the HTSC is considered in
the 3D modeling by assuming that the critical current density along thec-axisJcc
is one third of the critical current density within thea-bplaneJabc [47]. In order