Gas turbine engine, nacelle thereof, and associated method of operating a gas turbine engine

Abstract

The nacelle can have an inlet fluidly connecting a main gas path of a gas turbine engine core, the inlet having an inlet edge connecting an external skin to an internal duct wall, and a step formed in a surface of at least one of the skin and the duct wall, the step delimiting a first portion of the surface from a second portion of the surface, the second portion of the surface being recessed relative to the first portion of the surface, the second portion of the surface extending away from both the step and the inlet edge, whereas the first portion of the surface extends between the inlet edge and the step.

1 . An aircraft engine nacelle comprising an inlet fluidly connecting to a main gas path of a gas turbine engine core, the inlet having an inlet edge connecting an external skin to an internal duct wall, and a step formed in a surface of at least one of the external skin and the duct wall, the step delimiting a first portion of the surface from a second portion of the surface, the second portion of the surface being recessed relative to the first portion of the surface by a height of the step, the second portion of the surface extending away from both the step and the inlet edge, whereas the first portion of the surface extends between the inlet edge and the step. 
     
     
         2 . The aircraft engine nacelle of  claim 1  wherein the height of the step is of between 0.010″ and 0.200″ measured normal to the surface. 
     
     
         3 . The aircraft engine nacelle of  claim 1  wherein the step has a riser. 
     
     
         4 . The aircraft engine nacelle of  claim 1  wherein the aircraft engine is a turbofan engine, and the duct wall is an outer bypass duct wall. 
     
     
         5 . The aircraft engine nacelle of  claim 4  wherein the inlet edge is a portion of a D-duct, the D-duct connecting the skin and the duct wall. 
     
     
         6 . The aircraft engine nacelle of  claim 5  wherein the step is formed at a junction between the D-duct and the duct wall. 
     
     
         7 . The aircraft engine nacelle of  claim 5  wherein a heating air conduit is provided inside the D-duct, the heating air conduit having a plurality of heating air outlets, and being connected to a compressor bleed air source. 
     
     
         8 . The aircraft engine nacelle of  claim 4  wherein the inner duct wall has an acoustic panel, the step being located along the surface, between the inlet edge and the acoustic panel. 
     
     
         9 . The aircraft engine nacelle of  claim 1  wherein the step is formed in the duct wall. 
     
     
         10 . The aircraft engine nacelle of  claim 8  further comprising an other step formed in the skin, the other step delimiting a recessed portion of the skin, the recessed portion of the skin extending away from both the other step and the inlet edge. 
     
     
         11 . The aircraft engine nacelle of  claim 1  wherein the inlet edge, skin and duct are annular. 
     
     
         12 . The aircraft engine nacelle of  claim 11  wherein the step is backward facing. 
     
     
         13 . A method of operating a gas turbine engine, the method including a flow of air circulating along a surface of an inlet portion of the gas turbine engine, the flow of air drawing water droplets along the surface until the water droplets reach an edge of a step leading to a recessed portion of the surface, the flow of air separating the water droplets from the surface at the edge of the step. 
     
     
         14 . The method of  claim 13  wherein the method further comprises subjecting water in solid state to heating, and thereby transforming the water in solid state into the water droplets. 
     
     
         15 . The method of  claim 13  further comprising directing the detached water droplets into one of an engine core main gas path, or a bypass duct. 
     
     
         16 . An aircraft engine comprising a gas turbine engine core having a main gas path extending, in serial flow communication, across a compressor section, a combustor, and a turbine section, the gas turbine engine core housed within a nacelle, the nacelle having an inlet fluidly connecting the main gas path, the inlet having an inlet edge connecting an external skin to an internal duct wall, and a step formed in a surface of at least one of the skin and the duct wall, the step delimiting a first portion of the surface from a second portion of the surface, the second portion of the surface being recessed relative to the first portion of the surface, the second portion of the surface extending away from both the step and the inlet edge. 
     
     
         17 . The aircraft engine of  claim 16  wherein the step has a height of between 0.010″ and 0.200″ measured normal to the surface. 
     
     
         18 . The aircraft engine of  claim 16  wherein the aircraft engine is a turbofan engine, and the duct wall is an outer bypass duct wall. 
     
     
         19 . The aircraft engine of  claim 16  wherein the step is formed in the duct wall. 
     
     
         20 . The aircraft engine of  claim 16  wherein the inlet edge, skin and duct are annular.