where F is the maximum static friction of the scroll
expander and it can be considered as a constant. S is the
coefficient for the Coulomb friction of the scroll expander,
12. The overall friction of scroll mechanisms is a
main concern in the magnetic scroll design for reducing its
negative effect. Thus a simplified overall friction model to
the standard scroll expander is built and studied [11] (refer
to Equations (14) and (15), Figure 3). Equations (3)-(15)
express a complete thermodynamic model for the standard
scroll expander.