PILLAR-SHAPED BODY PROVIDED IN AIR FLOW PATH OF FAN

摘要

PURPOSE:To prevent any noise from being produced due to resonance of the captioned pillar-shaped body by providing a first pillar-shaped body transversely crossing the air flow path of a fan, and furthermore providing a second pillar- shaped body adjoining to said first pillar so as to cross an air flow in its orthogonal projection. CONSTITUTION:A first pillar-shaped body 4 of a diameter D1 is provided in an air duct 3 being the air flow path of a fan, while a second pillar-shaped body 5 of a diameter D2 is provided adjoining to the downstream side of the first pillar- shaped body 4 and spaced by a distance (l) therefrom. The second pillar-shaped body 5 crosses the first pillar-shaped body 4 at an angle of intersection of theta=90 deg. in orthogonal projection in the flow direction. Thus. a sound pressure level caused by Karman's vortex can be sharply reduced to prevent any noise from being produced due to resonance of the pillar-shaped body.