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Buoyancy Effects in Strongly-pulsed, Turbulent Diffusion FlamesThe objective of this experiment is to better understand the combustion behavior of pulsed, turbulent diffusion flames by conducting experiments in microgravity. The fuel jet is fully-modulated (i.e., completely shut off between pulses) by an externally controlled valve system leading to enhanced fuel/air mixing compared to acoustically excited or partially-modulated jets. Experiments are conducted both in laboratories at UW and WPI and in the GRC 2.2s Drop Tower. A single fuel nozzle with diameter d = 2 mm is centered in a combustor 20 x 20 cm in cross section and 67 cm in height. The gaseous fuel flow (ethylene or a 50/50 ethylene/nitrogen mixture by volume) is fully-modulated by a fast-response solenoid valve with injection times from tau = 4 to tau = 300 ms. The nominal Reynolds number based on the fuel velocity during injection, U(sub jet), is 5,000. A slow oxidizer co-flow properly ventilates the flame and an electrically heated wire loop serves as a continuous ignition source. Diagnostic techniques include video imaging, fine-wire thermocouples and thermopile radiometers, and gas sampling and standard emissions instruments (the last in the laboratory only).
Document ID
20040084207
Acquisition Source
Glenn Research Center
Document Type
Conference Paper
Authors
Hermanson, J. C.
(Washington Univ. Seattle, WA, United States)
Johari, H.
(Worcester Polytechnic Inst. MA, United States)
Ghaem-Maghami, E.
(Worcester Polytechnic Inst. MA, United States)
Stocker, D. P.
(NASA Glenn Research Center Cleveland, OH, United States)
Hegde, U. G.
(NASA Glenn Research Center Cleveland, OH, United States)
Date Acquired
August 21, 2013
Publication Date
June 1, 2004
Publication Information
Publication: Strategic Research to Enable NASA's Exploration Missions Conference
Subject Category
Inorganic, Organic And Physical Chemistry
Funding Number(s)
CONTRACT_GRANT: NCC3-673
CONTRACT_GRANT: NNC04AA37A
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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