| 摘要 |
An air turning vane and rail assembly for promoting laminar air flow in angled duct work transition sections includes longitudinally spaced apart air turning vanes transversely disposed between a pair of flat rails. Each turning vane is a hollow double-plate airfoil having a convex front airfoil plate, and a concave rear airfoil plate joined at their edges. Each rail has a plurality of longitudinally spaced apart, upstanding tabs each having an upper trapezoidally-shaped portion and a lower rectangularly-shaped pedestal portion. Each tab has a pair of laterally opposed, outwardly and downwardly angled edge walls, each joined at its lower end to a vertically disposed pedestal edge wall. The width of the pedestal is greater than the maximum lateral spacing between the front and rear airfoil plates. Thus, when a rail tab is inserted into an entrance opening between front and rear vane plates, wedging action of the angled tab side walls on the inner surfaces of the plates deforms the end portions of the plates to a flatter, less curved contour, causing the vane to firmly grip the tab. A protuberance protruding forward from the rear airfoil plate towards the front airfoil plate snaps into an aperture provided through the tab near its base, when a vane is pushed down on a tab sufficiently far, causing locking engagement in addition to a gripping engagement between vane and rail.
|
