The heat transfer characteristics of transformer vegetable oil-based nanofluid

To simulate the heat transfer characteristics of vegetable oil-based nanofluid under the condition of natural convection, we built up a 2-D axisymmetric thermal-fluid multiphysics coupled model in COMSOL Multiphysics. The effective thermal conductivity is calculated by the improved Maxwell model, the relationship between windings loss and temperature is also established. On this basis, the simulation of the movement and distribution of nanoparticles had completed. The results show that the heat transfer efficiency is better under the condition of vegetable oil-based silica nanofluid than that of vegetable oil. In the meanwhile, Nanoparticles easily stuck on the wall due to the small flow velocity near the boundary layer. Eddies at the upper part of the transformer are beneficial to the uniform distribution of nanoparticles.