Fundamental flame velocities of pure hydrocarbons 2: alkadienes Page: 3 of 14
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 E5OH25
The experimental technique is the same as that described in refers
ence I. A gaseous combustible mixture of pure hydrocarbon and dried
air of known composition was prepared and introduced into an evacuated,
pyrex, horizontal, cylindrical flame tube with an inside diameter of
25 millimeters and a length of 57 centimeters. An orifice, 8 milli-
meters in diameter, was placed at the ignition end of the flame tube.
A second orifice, 1.7 millimeters in diameter, was inserted at the
opposite end of the tube. A small methyl alcohol flame was the source
The linear or spatial observed flame velocity Uo is that velocity
component normal to the cross-sectional plane of the flame tube. It is
a function of hydrocarbon type and concentration and is dependent on
the geometry of the experimental apparatus. It was measured at room
temperature and atmospheric pressure by means of two photocells
placed at a known distance apart and connected to an electronic
timer. The uniformity of flame travel in the part of the flame tube
between the two photocells was confirmed by the rotating-drum-camera
method reported in reference I.
The fundamental flame velocity Uf is defined as the velocity
component normal to any tangent to the flame surface. It is a function
of hydrocarbon type and concentration and is entirely independent of
the geometry of the experimental apparatus. It was calculated by the
equation (reference 1)
Uf = (Uo-Ug)(At/A) (1)
Uf fundamental flame velocity
Uo linear flame velocity
Ug gas velocity ahead of flame
At cross-sectional area of flame tube
Af flame surface area
In order to evaluate the gas velocity ahead of the advancing
flame, the volumetric rate of flow was determined from motion pictures
of the progressive growth of a soap bubble blown from a tube connected
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.
Levine, Oscar; Wong, Edgar L. & Gerstein, Melvin. Fundamental flame velocities of pure hydrocarbons 2: alkadienes, report, November 3, 1950; (https://digital.library.unt.edu/ark:/67531/metadc58618/m1/3/: accessed April 19, 2019), University of North Texas Libraries, Digital Library, https://digital.library.unt.edu; crediting UNT Libraries Government Documents Department.