“Experts have studied the thermal modeling and temperature distribution characteristics of an aviation self ventilated air-cooled three-stage brushless generator, established a multi physics field fluid structure coupling model, analyzed the influence of different grid types on the numerical calculation efficiency of the fluid field, explored the influence of fan heat dissipation capacity and multi-stage structure on the air flow state, clarified the distribution characteristics of frictional resistance of each rotating component, and proposed a secondary equivalent method suitable for three-dimensional anisotropic modeling of windings, providing targeted guidance for the cooling design of three-stage brushless generators.”