Radial fan simulations by computational fluid dynamics and experimental validation

Fans are commonly used to refrigerate electrical machines when air forced cooling is required. They are rather simple solutions that can considerably improve the thermal performance of electrical machines, so the fan analysis could become an important point during the thermal design of electrical machines. This paper presents an analysis by computational fluid dynamics (CFD) simulations with the goal of characterizing radial fans, used in electrical machines. Different boundary conditions and parameters that affect to CFD results are evaluated in order to get an efficient way to simulate radial fans. The main objective is to obtain the flow-pressure characteristic curve of fans and airflow velocities by CFD simulations. Finally CFD simulation results of 2 fans are experimentally validated. One of them has been analysed in a fan testing wind tunnel. And the second one has been analysed in an auto-ventilated machine.