INLET DIFFUSER FOR JET ENGINE AND METHOD FOR DIFFUSING INCOMING AIR OF JET ENGINE
FIG6 is a composite diagram illustrating the performance of an inlet diffuser comprising a pair of elongate structures starting on an offset ramp surface of the inlet diffuser and having straight ramp edges
As seen in FIG6, an inlet diffuser 600 is an example of inlet diffuser 10 for a jet engine 130 that includes a pair of elongate structures 30 starting at a location removed from the inlet aperture 12 and having curved ramp faces 320. Inlet diffuser 600 includes a diffuser body 14 that defines an internal volume 16, an inlet aperture 12 by which ambient air enters the internal volume 16, and an exit aperture 18 by which air passes from the internal volume 16 of the inlet diffuser 10 to a downstream portion of a jet engine 130 that is operatively engaged with the exit aperture 18. The inlet diffuser 600 also includes the pair of elongate structures 30 extending longitudinally along an internal surface 20 of the diffuser body 14 that faces the internal volume 16. Each of the pair of elongate structures 30 includes a front end 32 that is located on a fore region 22 and a rear end 34 that is located on an aft region 24. In FIG6, the front end 32 is illustrated as being removed from the inlet aperture 12. The front end 32 is also illustrated in FIG6 as having a gradual increase 610 in altitude that splits the boundary layer air while reducing a size of a bow wave created by an interaction between the ambient air entering the inlet aperture 12 and the front end 32. FIG6 also shows the rear end 34 extending to a region upstream of exit aperture 18, and exhibiting a gradual decrease in altitude so as to reduce a wake coming off the rear end 34. FIG6 also shows perpendicular cross sections 610-640 that show the operation of the inlet diffuser 600 at different locations within the inlet diffuser 600. For example, cross section 610 illustrates the operation of the inlet diffuser 600 at a location near the inlet aperture 12. Cross section 610 shows a boundary layer of air that has formed on the internal surface 20.
diagram
600
inlet diffuser
20
surface
36
first portion
330
central sub volume
30
elongate structures elongate structure
12
inlet aperture
18
exit aperture
10
inlet diffuser inlet diffusers
70
channel
32
front end front ends
310
wall face wall faces
16
internal volume
630
Cross section
610
cross section
620
Cross section
38
second portions second portion
640
Cross section
34
rear end rear ends
320
ramp face ramp faces
26
offset slope surface
['1. An inlet diffuser (10) for a jet engine (130), the inlet diffuser (10) comprising: a diffuser body (14) defining an internal volume (16) facing outboard walls (230) and having an inlet (12) to the internal volume (16) for receiving incoming ambient air and an exit (18) from the internal volume (16) for delivering the air to a downstream portion of the jet engine (130), wherein the diffuser body (14) has an internal surface (20) facing the internal volume (16), the internal surface (20) comprising a fore region (22) proximate to the inlet (12) and an aft region (24) downstream of the fore region (22) and proximate to the exit (18), a pair of elongate structures (30) extending longitudinally along the internal surface (20) from the fore region (22) of the internal surface (20) to the aft region (24) of the internal surface (20), wherein the pair of elongate structure (30) defines a channel (70) of the internal volume (16) inboard of the elongate structures (30), wherein the pair of elongate structures (30) is configured to split a lower boundary of the air into a first portion (36) and a second portion (38) of boundary layer air such that the first portion (36) of the boundary layer air flows within the channel (70) between the pair of elongate structures (30) from the fore region (22) to the aft region (24), wherein a respective elongate structure (30) of the pair of elongate structures (30) comprises a wall face (310) extending substantially perpendicular to the internal surface (20) of the inlet diffuser (10) and extending along a longitudinal length of the respective elongate structure (30), wherein the wall face (310) is an inboard surface of the respective elongate structure (30) and is configured to restrict the first portion (36) of boundary layer air from flowing across the respective elongate structure (30), wherein the wall face (310) comprises an apex portion (64) opposite the internal surface (20), and wherein said respective elongate structure (30) of the pair of elongate structures (30) comprises a ramp face (320), said ramp face (320) is configured to: (i) extend from the apex portion (64) of the wall face (310) to a portion of the internal surface (20) of the inlet diffuser (10) that is outboard of the respective elongate structure (30), and (ii) extend along a longitudinal length of the respective elongate structure (30).', '8. The inlet diffuser (10) of any of claims 1-7, wherein the elongate structures (30) comprises a front end (32) located on the fore region (22), said front end (32) of each elongate structure (30) is configured to split said lower boundary of the air into the first portion (36) of boundary layer air and the second portion (38) of boundary layer air.', '11. The inlet diffuser (10) of any of claims 1-10, wherein each of the elongate structure (30) further comprises a rear end (34) located on the aft region (24).']