Axisymmetric thrust augmenting ejector with discrete primary air slot nozzles

• US 4,448,354 A
• Filed: 07/23/1982
• Issued: 05/15/1984
• Est. Priority Date: 07/23/1982
• Status: Expired due to Fees

• Current Assignee: The United States of America As Represented By The Secretary of Agriculture
• Original Assignee: United States Of America As Represented By The Secretary Of The Air Force
• Inventors: Franke, Milton E., Reznick, Steven G.
• Primary Examiner(s): Love, John J.
• Assistant Examiner(s): Forman, Michael J.
• Application Number:
  US06/401,163
• Time in Patent Office: 662 Days
• Field of Search: 239/DIG. 7, 239/265.11, 239/265.17, 417/196, 417/197
• US Class Current: 239/265.17
• CPC Class Codes: B64C 29/00 Aircraft capable of landing or taking-off vertically, e.g. vertical take-off and landing [VTOL] aircraft rotorcraft B64C27/00
• CPC Class Codes: F02K 1/36 having an ejector
• CPC Class Codes: Y02T 50/60 Efficient propulsion technologies, e.g. for aircraft
• CPC Class Codes: Y10S 239/07 Coanda

Abstract

A circular thrust augmenting ejector has an annular wall which defines a central passageway and a convergent contoured inlet section, a constant area cylindrical mixing section and a divergent conical diffuser outlet section. The inlet, mixing and outlet sections merge one into the next in axisymmetric serial relationship. The ejector also has a plurality of discrete primary nozzles arranged about the periphery of the annular wall at the entrance to the inlet section thereof for injecting a primary flow of high velocity air into the inlet section and thereby entraining a secondary flow of ambient air into the central passageway of the ejector.

Claims

1. A circular thrust augmenting ejector, comprising:

(a) a contoured inlet section having a surface;

(b) a constant area mixing section;

(c) a conical diffuser outlet section;

(d) said inlet, mixing and outlet sections merging one into the next in serial relationship, having a common central axis, and defining a central passageway; and

(e) a plurality of discrete primary nozzles positioned at the entrance but spaced from the surface of said contoured inlet section for injecting a primary flow of high velocity air into said inlet section with a trajectory generally parallel thereto and thereby entraining a secondary flow of ambient air into said central passageway of said ejector.

2. The circular thrust augmenting ejector as recited in claim 1, wherein each of said primary nozzles is formed by a curved, hook-like conduit terminating in a flattened, elongated end which defines a rectangular slot through which the primary air is injected into said inlet section of said ejector.

3. The circular thrust augmenting ejector as recited in claim 2, wherein each of said primary nozzles is mounted relative to said inlet section such that a gap is maintained between each nozzle end and the curved surface of said inlet section.

4. The circular thrust augmenting ejector as recited in claim 3, wherein said nozzles are mounted for adjustment of their pitch so as to vary the size of the gap between each nozzle end and the curved surface of said inlet section.

5. The circular thrust augmenting ejector as recited in claim 1, wherein said nozzles are spaced equidistant from one another around said inlet section.

6. The circular thrust augmenting ejector as recited in claim 5, wherein said nozzles are mounted for adjustment both relative to one another in a circumferential direction and along said inlet section in a radial direction.

7. The circular thrust augmenting ejector as recited in claim 1, wherein said plurality of primary nozzles are located along said inlet section outside of an imaginary extension of said central passageway upstream of said inlet section.

8. A circular thrust augmenting ejector, comprising:

(a) an annular wall which defines a central passageway. and a convergent inlet section, a cylindrical mixing section and a divergent outlet section in axisymmetric serial relationship; and

(b) a plurality of discrete primary nozzles arranged about the periphery of said annular wall at the entrance to said inlet section thereof for injecting a primary flow of high velocity air into said inlet section with a trajectory generally parallel thereto which achieves Coanda flow attachment of the primary air onto said annular wall at said mixing section where the separate primary air flows from said respective discrete nozzles hypermix with adjacent primary and secondary ambient air flows and at the same time entrain secondary ambient air into said ejector passageway;

(c) said plurality of primary nozzles being located along said annular wall at said inlet section thereof outside of an imaginary cylindrical extension of said central passageway upstream of said inlet section;

(d) said each of said primary nozzles being formed by a curved, hook-like conduit terminating in a flattened, elongated end which defines a rectangular slot through which the primary air is injected into said inlet section of said ejector;

(e) said each of said primary nozzles being mounted relative to said inlet section such that a gap is maintained between each nozzle end and said annular wall at said inlet section thereof.