Flush fluid inlet designs for aero-acoustic tone mitigation of aircraft

An aircraft comprising:

• an airframe;
• a rotor assembly and/or a pair of wings attached to the airframe;
• an engine assembly with an engine nacelle attached to the airframe, the engine nacelle including a washed surface across which fluid flows and a duct for intake of the fluid;
• and
• a fluid inlet device including:
• an inlet base mounted to the engine nacelle substantially flush with the washed surface, the inlet base having an outer base surface and defining an inlet mouth fluidly coupled with the duct;
• a pair of sidewalls adjoined at outer ends thereof to the inlet base, extending between a leading edge and a trailing edge of the inlet mouth, and projecting into the nacelle towards the duct;
• an inlet ramp interposed between and adjoining inner ends of the pair of sidewalls, the inlet ramp projecting into the engine nacelle at an oblique angle from the leading edge of the inlet mouth;
• and
• a highlight adjoining the inlet base and projecting from the trailing edge of the inlet mouth towards the leading edge of the inlet mouth, the highlight including a waveform profile extending crosswise relative to the inlet mouth and an outer highlight surface substantially coplanar with the outer base surface.

A method of manufacturing a fluid inlet device for a vehicle, the vehicle including a vehicle structure with a washed surface across which fluid flows and a duct for intake of the fluid, the method comprising:

• forming an inlet base configured to mount to the vehicle structure substantially flush with the washed surface, the inlet base including an outer base surface and defining an inlet mouth configured to fluidly couple with the duct;
• attaching a pair of sidewalls to the inlet base, the sidewalls extending between a leading edge and a trailing edge of the inlet mouth;
• attaching an inlet ramp to the inlet base with the inlet ramp interposed between the sidewalls, the inlet ramp projecting at an oblique angle from the leading edge of the mouth;
• and
• attaching a highlight to the inlet base, the highlight projecting from the trailing edge of the inlet mouth towards the leading edge of the inlet mouth and including a waveform profile, the highlight including an outer highlight surface located substantially coplanar with the outer base surface.

A fluid inlet device for a vehicle, the vehicle including a vehicle structure with a washed surface across which fluid flows and a duct for intake of the fluid, the fluid inlet device comprising:

• an inlet base configured to mount to the vehicle structure substantially flush with the washed surface, the inlet base defining an inlet mouth configured to fluidly couple with the duct;
• a pair of sidewalls attached to the inlet base and extending between a leading edge and a trailing edge of the inlet mouth;
• an inlet ramp interposed between and attached to the pair of sidewalls, the inlet ramp projecting at an oblique angle from the leading edge of the inlet mouth, the inlet ramp including an undulating curvature extending crosswise between the pair of sidewalls;
• and
• a highlight attached to the inlet base and projecting from the trailing edge of the inlet mouth towards the leading edge of the inlet mouth, the highlight including a waveform profile.

An aircraft comprising:

• an airframe;
• a rotor assembly and/or a pair of wings attached to the airframe;
• an engine assembly with an engine nacelle attached to the airframe, the engine nacelle including a washed surface across which fluid flows and a duct for intake of the fluid;
• and
• a fluid inlet device including:
• an inlet base mounted to the engine nacelle substantially flush with the washed surface, the inlet base defining an inlet mouth fluidly coupled with the duct;
• a pair of sidewalls adjoined at outer ends thereof to the inlet base, extending between a leading edge and a trailing edge of the inlet mouth, and projecting into the nacelle towards the duct;
• an inlet ramp interposed between and adjoining inner ends of the pair of sidewalls, the inlet ramp projecting into the engine nacelle at an oblique angle from the leading edge of the inlet mouth, the inlet ramp including an undulating curvature extending crosswise between the pair of sidewalls;
• and
• a highlight adjoining the inlet base and projecting from the trailing edge of the inlet mouth towards the leading edge of the inlet mouth, the highlight including a waveform profile extending crosswise relative to the inlet mouth.

A method of manufacturing a fluid inlet device for a vehicle, the vehicle including a vehicle structure with a washed surface across which fluid flows and a duct for intake of the fluid, the method comprising:

• forming an inlet base configured to mount to the vehicle structure substantially flush with the washed surface, the inlet base defining an inlet mouth configured to fluidly couple with the duct;
• attaching a pair of sidewalls to the inlet base, the sidewalls extending between a leading edge and a trailing edge of the inlet mouth;
• attaching an inlet ramp to the inlet base with the inlet ramp interposed between the sidewalls, the inlet ramp projecting at an oblique angle from the leading edge of the mouth, the inlet ramp including an undulating curvature extending crosswise between the sidewalls;
• and
• attaching a highlight to the inlet base, the highlight projecting from the trailing edge of the inlet mouth towards the leading edge of the inlet mouth and including a waveform profile.