{ PERMANENT_MAGNET.PDE }
title 'A PERMANENT-MAGNET PROBLEM'
Variables
A { z-component of Vector Magnetic Potential }
Definitions
mu
S = 0 { current density }
Px = 0 { Magnetization components }
Py = 0
P = vector(Px,Py) { Magnetization vector }
H = (curl(A)-P)/mu { Magnetic field }
y0 = 8 { Size parameter }
Initial values
A = 0
Equations
curl(H) + S = 0
Boundaries
Region 1
mu = 1
start(-40,0)
natural(A) = 0 line to (80,0)
value(A) = 0 line to (80,80) to (-40,80) to close
Region 2
mu = 5000
start(0,0)
line to (15,0) to (15,20) to (30,20) to (30,y0) to (40,y0) to (40,40)
to (0,40) to close
Region 3 { the permanent magnet }
mu = 1
Py = 10
start (0,0) line to (15,0) to (15,10) to (0,10) to close
Monitors
contour(A)
Plots
grid(x,y)
vector(dy(A),-dx(A)) as 'FLUX DENSITY B'
vector((dy(A)-Px)/mu, (-dx(A)-Py)/mu) as 'MAGNETIC FIELD H'
contour(A) as 'Az MAGNETIC POTENTIAL'
surface(A) as 'Az MAGNETIC POTENTIAL'
End