Deyu Li
Ansys Employee

Ω is nodal-based magnetic scalar potential, defined in the entire solution domain while ɸ is only in limited regions.

Reference papers:

Nonlinear T- Ω Formulation Including Motion for Multiply Connected 3-D Problems. 2008 P.Zhou

The second order finite element analysis of eddy currents based on the T-Ω method 2015 B.He