A 3D Inverse Design Method, where the 3-D blade profile is designed for a specified blade loading distribution, has been applied for designing a propeller fan rotor with high efficiency and low noise. A variety of the blade loading distributions (pressure jump across the blade), vortex pattern (forced vortex, free vortex, and compound vortex) and the stacking conditions (sweep angles) were specified and the corresponding 3-D blade configurations were obtained.
Propeller fans are widely used in a variety of equipments such as electric appliances (refrigerators, microwaves, etc.), air conditioners, automobile radiators, and cooling devices for PCs/servers. Due to the strong need for environment-friendly (low energy consumption, low noise) and lower manufacturing costs of such equipment, a new design technology enabling higher efficiency, smaller size, and lower noise are demanded. However, this is not an easy task and inevitably requires detail control of the three-dimensional (3-D) flow structures inside propeller fans.