Blade and axial impeller using same

Abstract

The present application discloses a blade and an axial-flow impeller using the same. The present application provides a blade, comprising a blade tip, a blade root, a leading edge and a trailing edge, wherein the leading edge and the trailing edge extend from the blade tip to the blade root, respectively. The blade is capable of rotating about a rotation axis X which is perpendicular to a normal plane. In a projection of the blade on the normal plane, a circumferential included angle between the leading edge and the trailing edge forms a wrap angle, and the wrap angle decreases gradually from the blade root to a middle blade height of the blade and increases gradually from the middle blade height to the blade tip. Wherein, the middle blade height is an arc line formed by center points of the blade tip and the blade root along a radial direction. The blade of the present application allows for significantly reduced turbulent vortices and reduced intensity in the vicinity of the junction of the leading edge and the blade tip of the blade and in the vicinity of the junction of the trailing edge and the blade tip of the blade during the operation of the axial-flow impeller, leading to evenly lightened load of airflow on the blade, more uniform distributions of velocity and pressure, reduced velocity and pressure pulsations, and reduced noise.