When the inlet flow velocity of the disc windings region in oil-immersed transformers is in the high Reynolds number range

the non-uniform oil flow distribution and abnormal reverse oil flow may arise in the bottom oil channels

resulting in an increase in the temperature of the hottest spot rather than a decrease. Therefore

this paper introduces a circular micro-guidance structure to optimize the uniformity of the insulating oil flow and to prevent the occurrence of localized reverse oil flow. Firstly

a flow rate ratio model controlled by both the Reynolds number and the geometric parameters of the micro-guidance structure is proposed based on dimensional analysis. By employing computational fluid dynamics (CFD) simulation technology to scan parameters

the functional form of the flow rate ratio coefficient is determined

achieving a maximum relative error of 5.286%

which allows for the precise prediction of the flow rate ratio in radial oil channels under varying micro-guidance structure dimensions. Secondly

a one-stage winding region experimental platform for transformers with added micro-guidance structures is designed to validate the accuracy of the CFD simulation results. On this platform

the impact of different radii and depths of the micro-guidance structures on the flow rate ratio is investigated

elucidating the suppression effect of the micro-guidance structures and identifying the optimal parameter combination. The results demonstrate that the micro-guide structure effectively suppresses reverse oil flow and identifies the optimal geometric parameters

thereby significantly enhancing the winding cooling performance.