High efficiency to diameter ratio and low weight axial flow fan

摘要

A high efficiency axial flow fan includes a hub, fan blades and a circular band. The hub rotates about a rotational axis when torque is applied from a shaft rotatably driven by a power source. The circular band is concentric with the hub, connected to the tip of each blade, and is spaced radially outward from the hub. The blades are configured to produce an airflow when rotated about the rotational axis. Each blade has a chord length distribution, stagger angle and dihedral distribution which varies along the length of the blade. The dihedral distance of each blade varies as a function of blade radius from the rotational axis.