Influence of the Thermophysical Model on the CFD Analysis of Oil-Cooled Transformer Windings

A disc-type winding of an oil-immersed power transformer is modeled with Computational Fluid Dynamics. Different approaches are implemented to evaluate the feasibility Boussinesq approximation: (i) constant fluid properties, (ii) variable viscosity and thermal diffusivity (iii) temperature-dependent properties. Temperature flow distributions reconstructed put into relation physical phenomena model assumptions. Their comparison suggests that numerical results fairly sensitive thermophysical as long buoyancy force a relevant component flow. Nonetheless, all cases converge very close predictions hot-spot value location, possibly positive implications for use reference parameters when deriving heat transfer correlations this topic.