BLADES FOR LOW SPEED PROPELLER FAN

摘要

Blade for low speed propeller ventilator has roughened surface on intake side, with roughness increasing away from leading edge. The propeller ventiator has a section, fastened to a rotating hub carrying radially outward projecting blades. Each blade has a roughened surface on part of its suction side. The roughness increases gradually from the leading edge of the blace towards the trailing edge. The roughened area is formed by fine grooves or ribs.