CFD simulation and investigation on flow field characteristics and temperature predictions of an electric generator unit

In order to evaluate the cooling performance and thermal characteristics of an electrical generator unit, a three-dimensional model with and without fluid–solid temperature coupling is established and the model reliability is verified by temperature experiments. Results show that the air quantity distribution of each cooling air duct of the engine in original electric generator is uneven and there is a zero-velocity zone in the local area of the muffler. After structural improvement, the uniformity of air quantity distribution improves significantly and the surface velocity of muffler cover increases. The simulated temperature values of magneto surface and muffler front cover obtained are in good agreement with the experimental values, having the relative error of 5.8% and 4.9%, respectively. The maximum temperature of engine body, winding coil of magneto, and inverter is 200 ℃, 137.13 ℃, and 91.66 ℃, respectively. The research results can be used to quantitatively evaluate the cooling characteristics of electric generator.