Papers presented to the 11th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, South Africa, 20-23 July 2015.
In this paper accurate modelling of heat transfer
from power transformer winding conductors to
cooling oil is envisaged. To this end the network
model of Radakovic & Sorgic  is validated against
more detailed CFD simulation results.
Based on this comparison, three model
improvements to the network model are proposed.
They concern the governing heat transfer correlation,
the introduction of thermal boundary layer tracking
and an improved description for the thermal resistance
in the solid. The improved network model results in
more accurate results.
The authors acknowledge support from the IWT,
in the context of a Baekeland Mandate.