CFD Techniques Applied to Axial Fans Design of Electric Motors

C3 - CFD Validation Studies

The objective of this work is to present axial fan applications in electric motors. Electric motors are widely used by humans to convert electric energy into mechanical energy. This converting process is characterized by generating losses, which are transformed into heat. To ensure the quality, safety, performance and/or efficiency of the motor this generated heat must be removed, therefore, most of the motors comprise air cooling systems. Among the components of the cooling systems, the fans paramount. The fans can be used externally, internally or both in an electric motor, these configurations depend on the motor characteristics and its applications.
A correct fan design is very important for the temperature, losses and noise of the motor to be kept below the limits imposed by standards and/or customers. Therefore, the engineer or designer must apply the concepts of turbomachines and electric machines to properly design cooling systems.
The fans can be comprised of axial or radial rotors. In this approach, the axial rotors will be focused. Advantages and disadvantages, design fan concepts, design using computational fluid dynamics (CFD) and cases studies, will be presented.
Many design details will be considered, such as: applications and assembling, typical curves, similarity laws using CFD, CFD validation, fan design and fans troubleshooting.