CFD Investigation of Temperature Distributions by Non-uniform Heat Losses inside Windings

this paper shows the application of (Computational Fluid Dynamics) CFD method to predict the hot-spot temperature (HST) at different operating conditions inside the disc-type winding. It is very well-known that electrical heat losses are not distributed uniformly inside windings of power transformers due to the flux leakages in the winding; therefore, the influences of the non-uniform heat losses in the conductors of the winding are investigated and compared with the uniform heat losses distribution at different mass flow rates. Moreover, experimental verifications arc provided to support 3D CFD simulations in the oil-directed (OD) cooling modes. The accurate numerical results of CFD simulations include the average temperature in each pass, the hot-spot location (HSL) at different dimensionless eddy losses factor (Qeddv). The presented results give a deep insight into the thermal aspects of the disc-type windings enabling the designer to optimize the cooling conditions of power transformer windings.