To the innovative magnetic scroll expander, the magnetic
field distribution resulting from the two magnetized spirals
is analysed in this section, which leads to generate the
driving magnetic force and torque. When the magnetic
scroll expander is in motion, we assume that the expander is
running stably and the clearances (air gaps) between the
moving scroll and the fixed scroll are consistent. With such
assumptions, the magnetic field distribution corresponds to
the scroll expander orbit angle (position), not related to the
rotor rotation speed. To be more specific, because the orbit
angle indicating the moving scroll location repeats in
cycles, the magnetic field distribution and the generalized
force from the magnetic field are periodic variations.
Therefore, to every relative location between the moving
scroll and the fixed scroll, we can consider to analysis the
magnetic scrolls and the generalized force/torque from the
fundamentals of the steady magnetic field. The finite
element method has been used by ANSYS Maxwell. Figure
5 shows the simulation results for the magnetic field
strength distributions when the relative positions of two
scrolls are at two specific orbit angles (0o, 90o) and the
magnetic flux density of the moving scroll.