Effect of Initial Mixture-Temperature on Burning Velocity of Hydrogen-Air Mixtures With Preheating and Simulated Preburning Page: 3 of 24
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 TN 4156
easier by preheating but not by preburning. The question was raised as
to whether similar behavior would be shown by a nonhydrocarbon fuel. Ac-
cordingly, the effects of preheating and preburning on the burning veloc- *
ity of hydrogen-air mixtures were investigated at initial temperatures
from about 3000 to 7000 K. The temperature was raised in two ways:
(1) by preheating of the hydrogen-air mixture and (2) by simulated adia-
batic preburning of part of the hydrogen in air. The principal difference
between the two methods of raising the initial temperature is that pre-
heating raises the total enthalpy and flame temperature of the mixture,
whereas in preburning the total enthalpy and flame temperature remain
The burning velocities of the two types of mixtures were determined
by the Bunsen burner technique (ref. 2, p. 459) with schlieren optics.
The burner was heated by individually controlled lengths of resistance -'
wire. Preburning was simulated by adding water vapor and nitrogen to the
hydrogen-air mixtures in the proper amounts.
A axial cross-sectional area of flame cone, cm2
bc empirical constants, dimensionless
h height of flame cone, cm
I slant height or length of generating curve of flame cone, cm
M molecular weight, g/g-mole
n empirical exponent for temperature dependence, dimensionless
P total pressure of mixture
Q volumetric flow of mixture, cm3/sec
R gas constant, cal/(g-mole)(OK)
S lateral surface area of flame cone, cm2
To initial temperature, OK
u burning velocity, cm/sec
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.
Heimel, Sheldon. Effect of Initial Mixture-Temperature on Burning Velocity of Hydrogen-Air Mixtures With Preheating and Simulated Preburning, report, October 1957; (https://digital.library.unt.edu/ark:/67531/metadc56795/m1/3/: accessed April 20, 2019), University of North Texas Libraries, Digital Library, https://digital.library.unt.edu; crediting UNT Libraries Government Documents Department.