Nacelle air scoop assembly

Abstract

An air scoop assembly that may be for a nacelle of a turbofan engine includes a surface defining at least in-part a primary flowpath and a hood formed to the surface and projecting into the primary flowpath. The hood includes a distal, leading, edge that is irregular in shape thereby producing air vortices that shed from the leading edge and co-extend in a downstream direction with an airstream in the primary flowpath. The vortices are thereby controlled such that air flow disruption and undesired resonance is minimized or eliminated.

What is claimed is: 
     
         1 . An air scoop assembly configured to mount to a surface defining a primary flow path, the air scoop assembly comprising:
 a hood having an irregular upstream edge and configured to project into the primary flowpath.   
     
     
         2 . The air scoop assembly set forth in  claim 1 , wherein the edge is at least one vortex generator. 
     
     
         3 . The air scoop assembly set forth in  claim 2 , wherein the edge is scalloped. 
     
     
         4 . The air scoop assembly set forth in  claim 2  further comprising:
 an air duct having an inlet defined at least by the surface and the edge. 
 
     
     
         5 . The air scoop assembly set forth in  claim 4 , wherein the air duct defines a secondary flowpath in fluid communication with the primary flowpath and for the intermittent flow of air from the primary flowpath. 
     
     
         6 . The air scoop assembly set forth in  claim 5  further comprising:
 a valve configured for the intermittent isolation of the secondary flowpath. 
 
     
     
         7 . The air scoop assembly set forth in  claim 6 , wherein the valve includes a closed position and an open position and the at least one vortex generator forms at least one vortices that breaks up any coherent shedding off of air flow from the hood when the valve is in the closed position. 
     
     
         8 . The air scoop assembly set forth in  claim 2 , wherein the edge has at least one apex projecting in an upstream direction and into the primary flowpath. 
     
     
         9 . The air scoop assembly set forth in  claim 7 , wherein the edge has at least one apex projecting into an upstream direction and into the primary flowpath. 
     
     
         10 . The air scoop assembly set forth in  claim 9 , wherein the hood is flush with the surface. 
     
     
         11 . The air scoop assembly set forth in  claim 9 , wherein the hood projects transversely into the primary flowpath and outward from the surface. 
     
     
         12 . The air scoop assembly set forth in  claim 9 , wherein the surface is carried by a nacelle. 
     
     
         13 . The air scoop assembly set forth in  claim 8 , wherein the apex projects upstream by a downstream-most portion of the edge by a distance that is about twice a thickness of the hood. 
     
     
         14 . The air scoop assembly set forth in  claim 8 , wherein the at least one apex is spaced from a next adjacent apex by a distance that is about one fifth to about one half a height of the hood. 
     
     
         15 . A nacelle for a gas turbine engine comprising:
 a fan cowling concentrically disposed to an engine axis and surrounding a fan section of the gas turbine engine;   a core cowling concentrically disposed to the engine axis and located downstream of the fan section with an annular air bypass flowpath defined between and by the fan and core cowlings; and   a hood formed to the core cowling and projecting into the bypass flowpath, the hood including a leading edge that includes at least one apex projecting in an upstream direction and acting as at least one vortex generator.   
     
     
         16 . The nacelle set forth in  claim 15  further comprising:
 an air duct having an inlet defined at least by the core cowling and the edge; and 
 wherein the air duct defines a secondary flowpath in fluid communication with the bypass flowpath and for the intermittent flow of air from the bypass flowpath. 
 
     
     
         17 . The nacelle set forth in  claim 16  further comprising:
 a valve in the air duct for the intermittent isolation of the secondary flowpath; and 
 wherein the valve includes a closed position and an open position and the at least one vortex generator forms at least one vortex that breaks up any coherent shedding off of air flow from the hood when the valve is in the closed position. 
 
     
     
         18 . The nacelle set forth in  claim 15 , wherein the hood is flush with the core cowling. 
     
     
         19 . The nacelle set forth in  claim 15 , wherein the hood projects transversely into the bypass flowpath and radially outward from the core cowling. 
     
     
         20 . A method of operating an air scoop assembly comprising the steps of:
 substantially closing the air scoop assembly having a hood that projects into a primary air flowpath; and   forming at least one air vortex that stems from an irregular leading edge of a hood of the air scoop assembly and extends in a substantially downstream direction thereby minimizing disruption of airstreams in the primary air flowpath.