Heat transfer phenomenon and location prediction as well as disc-type transformer windings have attracted many researches in recent years. The motivation is based on noticeable effects of these issues on transformers endurance, reliability, and functionality. This paper focuses on developing a sufficiently accurate CFD model to carry out studies and address some guidelines for disc-type transformer windings with zigzag cooling path with a reasonable resource . The discs composed from copper wires and paper insulators wrapped around them. Accounting for this inhomogeneity by zone distinction in CFD model results in many computational subdomains in very small size, which makes model development and mesh generation difficult and also computational costs, very high. In this paper, using definition functions, a method is introduced that for different material properties with no need to resolve solution subdomains. dependency of thermo-physical properties such as conductivity, , and density have been taken care of. Results show that using , model development, and also solution time noticeably reduced without any considerable in numerical results. Furthermore, using Ansys Workbench capabilities for , i.e. geometry reconstruction and mesh generation, effects of several parameters on transformer cooling condition have been investigated. Finally, some guidelines for such transformers design have been addressed.