Jet-flap, wing-blowing system for use in short takeoff and landing aircraft is described. System depends on ejector nozzle with large blowing capacity to direct ducted air against deflected flap. Operation of equipment during takeoff and cruise conditions is discussed. Diagrams of equipment are provided

True, H. C.

English

NASA Technical Reports Server

October 1972	 B72-10693 
NASA TECH BRIEF 
Ames Research Center
	 -4r 
NASA Tech Briefs announce new technology derived from the U.S. space program. They are issued to encourage 
commercial application. Tech Briefs are available on a subscription basis from the National Technical Information 
Service, Springfield, Virginia 22151. Requests for individual copies or questions relating to the Tech Brief program may 
be directed to the Technology Utilization Office, NASA, Code KT, Washington, D.C. 20546. 
Ejector Nozzle with Massive Blowing 
A novel ejector nozzle jet-flap wing-blowing system 
for use in short-take-off-and-landing aircraft (STOL) 
may provide many of the desirable features of two-
stream "quiet" augmentor flap systems, that is, low 
noise, high lift, etc. The new system directs all or 
Spoiler	 Door 
Nozzles
Ramp 
Duct	 Lower 
Ejector
Ta ke-off 
most of the fan airflow to the wing through a duct-
and-nozzle system like those presently used in aug-
mentor-wing designs. The ejector nozzle system makes 
use of a relatively short acoustically lined ejector to 
obtain sound suppression and some thrust augmenta-
tion. The ejector exit forms a thick slot-type nozzle 
near the knee of the flap, and coanda turning is used 
to achieve high lift. The dimensions of the ejector, 
relative to the multielement nozzle dimensions, are 
sized to achieve the degree of noise suppression and 
amount of multielement flow mixing desired. The 
ejector nozzle makes possible the use of a simpler and 
lighter flap structure, and also permits incorporation 
of a wing-mounted thrust reverser with the ejector 
segments; use of the nozzle provides "uncoupling," 
that is, the ability to optimize noise suppression and 
lift characteristics independently of each other. 
The results of tests of a plain jet flap with a multi-
element nozzle indicate that the new system has a
noise level as low as the augmentor wings in present 
use. The use of ejector nozzles simplifies many of the 
flow turning problems at high flap angles because a 
single thick flap allows a larger flap radius and because 
the ejector exit area can be adjusted as a function of 
flap angle to obtain a satisfactory ratio of flap radius 
to blowing-nozzle height. The single thick flap could 
also contain a conventional duct nozzle to aid in at-
taching the ejector airflow. However, the thrust in the 
wing is an order of magnitude larger owing to massive 
blowing and, therefore, different geometries are re-
quired to achieve maximum performance. 
The above diagram shows the principal elements 
of the ejector nozzle jet-flap concept; for simplicity, 
linkages and other mechanical details are omitted. 
The configuration is for take-off, and the air streams 
from the nozzle are channeled between the door and 
the lower ejector and its ramp; this mode of operation 
provides the high values of lift required for short take 
offs. The gap between the ramp and the flaps can be 
open for maximum takeoff thrust. For a cruise mode, 
the nozzles are inoperative; the door, ejector, ramp, 
and the flap are positioned as shown below. 
Cruise 
The landing configuration shown below is quite 
similar to the takeoff arrangement, except that the flap 
deflection is higher and the gap between the ramp 
(continued overleaf) 
This document was prepared under the sponsorship of the National
	 Government assumes any liability resulting from the use of the 
Aeronautics and Space Administration. Neither the United States
	 information contained in this document, or warrants that such use 
Government nor any person acting on behalf of the United States
	 will be free from privately owned rights.
https://ntrs.nasa.gov/search.jsp?R=19720000692 2020-03-17T03:43:35+00:00Z
and flap is closed to enhance the attachment of the 
ejector airflow to the flap.
higher position than in other modes of operation and 
the ramp is rotated into the air stream issuing from 
the nozzles. The ramp thus acts as a blocker door, and 40 
the thrust reversing pocket is seen to be the volume 
formed by the lower ejector, the ramp, and the door. 
Landing 
Thrust reversal can also be provided by suitable 
disposition of the working elements; as indicated in 
the diagram below, the door is elevated to a much
Notes: 
1. The door dimensions are determined by noise and 
flow mixing requirements. 
2. No additional documentation is available. Specific 
questions, however, may be directed to: 
Technology Utilization Officer 
Ames Research Center 
Moffett Field, California 94035 
Reference: B72-10693 
Patent status: 
NASA has decided not to apply for a patent. 
Source: Harold C. True of 
The Boeing Company 
under contract to 
Ames Research Center 
(ARC-10621) 
B72-10693	 Category 06


Ejector nozzle with massive blowing

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