Experimental investigation of screeching combustion in full-scale afterburner Page: 4 of 64
This report is part of the collection entitled: National Advisory Committee for Aeronautics Collection and was provided to Digital Library by the UNT Libraries Government Documents Department.
The following text was automatically extracted from the image on this page using optical character recognition software:
NACA RM E53I01
The engine with afterburner was installed in the altitude wind
tunnel on a wing segment that spanned the 20-foot-diameter test section.
Dry refrigerated air was supplied to the engine from the make-up air system
through a duct connected to the engine inlet.
During the investigation, 43 afterburner configurations were used.
These configurations were produced through alterations to the diffuser,
the flame holder, and the fuel injection system. The combination of
alterations used to make up each of the configurations is summarized
in table I. Details of modifications to the various components are
described in the following paragraphs.
Diffuser. - Five diffuser innerbodies were used, the details of which
are shown in figure 2. These innerbodies include the original configura-
tion (a), three modifications of the original (b, c, and d) designed to
form a pilot or flame-holding surface at the downstream end of the inner-
body as a possible means of improving burner stability at low burner
pressures, and one modification (e) designed to eliminate (or keep to a
minimum) air-flow separation from the innerbody. Antiswirl vanes attached
to the skin of the innerbody were installed at the diffuser inlet on 29
of the configurations to reduce turbine-outlet swirl and thereby alter
the radial mass, or velocity, distribution. Thirteen configurations nad
sets of 33 short antiswirl vanes (fig. 3(a)), while 16 configurations
had sets of 48 full-passage vanes (fig. 3(b) and (c)). A boundary-layer
tripper (fig. 4) was installed on the innerbody of configuration 43 to
alter the mass and velocity distributions.
Flame holders. - The 13 flame holders used in the investigation are
illustrated in figure 5. All but three of these were conventional V-gutter
flame holders having projected areas that blocked from 29 to 46.8 percent
of the flow area at the flame-holder position. The gutter widths of these
flame holders ranged from 1 to 5. inches, and the number of annular gutter
elements varied from one to four. The three exceptions to this general
arrangement were flame holders (I), (K), and (L). Flame holder (I)
(fig. 5(i)) had two U-shaped circular gutter elements; flame holder (K)
(fig. 5(k)) comprised U- and V-shaped elements combined to form a star
design; and flame holder (L) was a conventional V-gutter incorporating
a long water-cooled annular splitter. The significance of these three
designs will be discussed in a later section of this report. The flame
holders were installed in several longitudinal positions along the after-
burner, as indicated in figure 6 and table I.
Fuel-spray bars. - Fuel was injected into the afterburner normal to
the direction of gas flow through conventional spray-bar fuel injectors.
A total of 13 fuel-spray-bar designs was used, the details of which are
Here’s what’s next.
This report can be searched. Note: Results may vary based on the legibility of text within the document.
Tools / Downloads
Get a copy of this page or view the extracted text.
Citing and Sharing
Basic information for referencing this web page. We also provide extended guidance on usage rights, references, copying or embedding.
Reference the current page of this Report.
Usow, Karl H.; Meyer, Carl L. & Schulze, Frederick W. Experimental investigation of screeching combustion in full-scale afterburner, report, December 4, 1953; (https://digital.library.unt.edu/ark:/67531/metadc62147/m1/4/: accessed April 20, 2019), University of North Texas Libraries, Digital Library, https://digital.library.unt.edu; crediting UNT Libraries Government Documents Department.