Low-noise, high efficiency fan assembly combining unequal blade spacing angles and unequal blade setting angles

Abstract

A vehicle engine-cooling fan assembly for circulating air to cool an engine. The fan assembly has a central hub with a plurality of blades extending radially outward from the central hub. Each blade has a root joined to the central hub, a tip, and a span formed between the root and the tip. The blades are spaced circumferentially from each other, by unequal spacing angles, around the central hub. The unequal spacing angles minimize noise produced by the fan assembly. The blades are positioned at a radial location along a blade span by unequal setting angles which increase the efficiency of the fan assembly. The blades can have either a straight or a curved planform. Mechanical energy is imparted to the fan assembly from an electric motor, a hydraulic motor, or some other source. Also disclosed is a process for designing a vehicle fan assembly combining unequal fan blade spacing angles and unequal fan blade setting angles.