Three-Dimensional Primary Design of a 3kW Class Electronically Commutated Motor Fan Impeller

Fans are one of the biggest energy consumers in any industrial plant. Nowadays, fans are critical to the efficient performance of air handling systems. In Korea, the government is taking measures to build efficient fan technology. Electronically Commutated (EC) fans are an ideal choice because they provide advantages such as reduced energy consumption, variable speed operation, low operating noise, and increased reliability. In the present study, an EC mixed-flow fan is designed and its performance is evaluated using steady-state numerical analysis. Fan performance curves are obtained when the fan is analyzed using different flow rates and rotating speeds. The numerical studies aimed to analyze fan performance based on operating conditions like rotating speed, flow rate, impeller tip diameter, and total pressure as provided by the fan manufacturer. Steady-state Reynolds Averaged Navier-Stokes equations (RANS) were solved on the generated mesh with a Shear Stress transport (SST) turbulence model implemented on the three-dimensional (3D) mesh. The numerical results are validated by comparing them with specification data provided by the fan manufacturer. The input power of 2.97 kW obtained through computational analysis is identical to the power rating required by the fan manufacturer. This indicates the reliability of the impeller design presented in this research. The blade loading plot shows that both the suction and pressure sides of the impeller blade show a smooth gradient without abrupt changes, indicating a good aerodynamic design of the blade. The pressure distribution plots signify that there is a significant rise in pressure when the flow passes through the impeller blades. In these plots, the pressure changes are not abrupt with a few exceptions on suction side of blade, which suggests flow separation occurred on suction side of blade. The velocity vector plot depicted efficient energy conversion by impeller blades. It also highlighted energy losses due to formation of a stagnation zone.