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The effect of incomplete fuel-air mixing on the lean limit and emissions characteristics of a Lean Prevaporized Premixed (LPP) combustorResults are presented from an experimental study of the effect of incomplete fuel-air mixing on the lean limit and emissions characteristics of a lean, prevaporized, premixed (LPP), coaxial mixing tube combustor. Two-dimensional exciplex fluorescence was used to characterize the degree of fuel vaporization and mixing at the combustor inlet under non-combusting conditions. These tests were conducted at a pressure of 4 atm., a temperature of 400 C, a mixer tube velocity of 100 m/sec and an equivalence ratio of .8, using a mixture of tetradecane, 1 methyl naphthalene and TMPD as a fuel simulant. Fuel-air mixtures with two distinct spatial distributions were studied. The exciplex measurements showed that there was a significant amount of unvaporized fuel at the combustor entrance in both cases. One case, however, exhibited a very non-uniform distribution of fuel liquid and vapor at the combustor entrance, i.e., with most of the fuel in the upper half of the combustor tube, while in the other case, both the fuel liquid and vapor were much more uniformly distributed across the width of the combustor entrance. The lean limit and emissions measurements were all made at a pressure of 4 atm. and a mixer tube velocity of 100 m/sec, using Jet A fuel and both fuel-air mixture distributions. Contrary to what was expected, the better mixed case was found to have a substantially leaner operating limit. The two mixture distributions also unexpectedly resulted in comparable NO(x) emissions, for a given equivalence ratio and inlet temperature, however, lower NO(x) emissions were possible in the better mixed case due to its leaner operating limit.
Document ID
19940024762
Document Type
Conference Paper
Authors
Santavicca, D. A.
(Pennsylvania State Univ. University Park, PA, United States)
Steinberger, R. L.
(Pennsylvania State Univ. University Park, PA, United States)
Gibbons, K. A.
(Pennsylvania State Univ. University Park, PA, United States)
Citeno, J. V.
(Pennsylvania State Univ. University Park, PA, United States)
Mills, S.
(Pennsylvania State Univ. University Park, PA, United States)
Date Acquired
August 16, 2013
Publication Date
September 1, 1993
Publication Information
Publication: AGARD, Fuels and Combustion Technology for Advanced Aircraft Engines
Subject Category
Inorganic And Physical Chemistry
Accession Number
94N29265
Distribution Limits
Public
Copyright
Other
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