INLET DIFFUSER FOR JET ENGINE AND METHOD FOR DIFFUSING INCOMING AIR OF JET ENGINE
FIG7 is a composite diagram illustrating the performance of an inlet diffuser comprising two pairs of elongate structures having straight ramp edges
As seen in FIG7, an inlet diffuser 700 is an example of inlet diffuser 10 for a jet engine 130 that includes multiple pairs of elongate structures 30. Inlet diffuser 700 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 700. Inlet diffuser 700 also includes an inner pair 710 of elongate structures 30 and an outer pair 720 of elongate structures 30. Inner pair 710 and outer pair 720 of elongate structures 30 extend longitudinally along an internal surface 20 of the diffuser body 14 that faces the internal volume 16. FIG7 also shows perpendicular cross sections 710-740 that show the operation of the inlet diffuser 700 at different locations within the inlet diffuser 700. For example, cross section 710 illustrates the operation of the inlet diffuser 700 at a location near the inlet aperture 12. Cross section 710 shows inner pair 710 of elongate structures 30 and outer pair 720 of elongate structures 30. Each of the elongate structures 30 includes inboard wall faces 310 and outboard ramp faces 320 that have a straight slope. The wall faces 310 of the inner pair 710 of elongate structures 30 define the outboard boundaries of a channel 70. In cross section 710, it is seen how the elongate structures 30 split the incoming boundary layer air into a first portion 36 of boundary layer air that is located within channel 70 and multiple second portions 38 of boundary layer air that are located outboard of the inner pair 710 of elongate structures 30.
diagram
30
elongate structures elongate structure
12
inlet aperture
38
second portions second portion
710
inner pair
22
fore region
18
exit aperture
740
Cross section
20
surface
16
internal volume
320
ramp face ramp faces
10
inlet diffuser inlet diffusers
720
outer pair Cross section
36
first portion
70
channel
330
central sub volume
700
inlet diffuser
['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).']