Abstract
This paper presents an investigation on ac losses of superconducting bulk with the help of finite element software of Comsol Multiphysics. The calculation ac loss result was compared with that from analytical formulas for type-II superconducting slab and cylinder. Three different geometries of the columnar bulk are analyzed, which are bulk with no core, bulk with a central columnar air core, and bulk with a central columnar iron core. The core is parallel to the c-axis of bulk. The temperature dependence of the ac loss is presented, and the thermal behavior of the bulk is analyzed by associating ac loss with heat transfer characteristic through the external surface of the bulk sample.