144x Filetype PPTX File size 1.70 MB Source: www.fire.tc.faa.gov
Gas Turbines and Chemical Kinetics Coupling chemical kinetics and computational fluid mechanics for engine design Kinetically limited processes Nitrogen oxide production Soot formation Flame stability Blow out J Campbell, J. Chambers, Patterns in the sky: natural visualization of aircraft flow fields. NASA SP- 2 514,1994 Aviation Fuels – Composition Carbon Number Distributions Hydrocarbon Class Distribution JP-4 n-Parafins Cycloparafins JP-8 i-Parafins JP-7 Naphthalenes Alkylbenzenes Distillation Temperature T. Edwards, L.Q. Maurice, J. Propulsion Power 17 (2001) 3 Aviation Fuels – Fuel Variability e e m m Fraction of delivered JP-8 fuels with specified properties u u l l o o V V l l a a t Aromatics Content t Cetane Index o o T T f f o o e e g g a a t t n n e e c c r r e e P 40 P 50 35 30 40 25 30 20 15 20 10 10 5 0 0 12 14 16 18 20 22 24 36 39 42 45 48 51 Volume % Cetane Index Significant variability in physical and chemical properties Current certification not highly constraining Petroleum Quality Information System Annual Report (2009) 4 Surrogate Fuel Concept Computational fluid Real Diesel t Real Fuel n u dynamics coupled with o m eA detailed chemical kinetics c n a requires a simplified fuel d n u Molecular Weight b Surrogate Fuel model A Surrogate Diesel t n u o m A Molecular Weight Distillation Temperature Ideal surrogate fuel must emulate combustion behavior and physical properties of a target real fuel 5 Surrogate Fuels – Previous Work Numerous jet fuel surrogate postulations present in literature (e.g.): Sarofim et al. ─ Surrogate fuel to model jet fuel pool fires Bruno et al. ─ Surrogate fuel to model thermo-physical properties of jet fuel Require detailed characterizations of target fuel (GC, NMR, …) Significant uncertainty in chemical kinetics of selected surrogate compounds Sarofim et al., Combust. Sci. Tech, 177 (2005) 715–739 T.J. Bruno et al., Ind. Eng. Chem. Res 45 (2006) 4371–4380 6
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