0
Research Papers: Gas Turbines: Combustion, Fuels, and Emissions

An Improved Core Reaction Mechanism for Saturated C0 -C4 Fuels

[+] Author and Article Information
Chitralkumar V. Naik1

 Reaction Design, 6440 Lusk Blvd, Suite D-205, San Diego, CA 92121cnaik@reactiondesign.com

Karthik V. Puduppakkam, Ellen Meeks

 Reaction Design, 6440 Lusk Blvd, Suite D-205, San Diego, CA 92121

1

Corresponding author.

J. Eng. Gas Turbines Power 134(2), 021504 (Dec 20, 2011) (15 pages) doi:10.1115/1.4004388 History: Received April 25, 2011; Revised April 26, 2011; Published December 20, 2011; Online December 20, 2011

Accurate chemistry models are required to predict the combustion behavior of different fuels, such as synthetic gaseous fuels and liquid jet fuels. A detailed reaction mechanism contains chemistry for all the molecular components in the fuel or its surrogates. Validation studies that compare model predictions with the data from fundamental combustion experiments under well-defined conditions are least affected by the effect of transport on chemistry. Therefore they are the most reliable means for determining a reaction mechanism’s predictive capabilities. Following extensive validation studies and analysis of detailed reaction mechanisms for a wide range of hydrocarbon components reported in our previously published work (Puduppakkam , 2010, “Validation Studies of a Master Kinetic Mechanism for Diesel and Gasoline Surrogate Fuels,” SAE Technical Paper No. 2010-01-0545; Naik , 2010, “Validated F-T Fuel Surrogate Model for Simulation of Jet-Engine Combustion,” Proc. ASME Turbo Expo, Paper No. GT2010-23709; Naik , 2010, “Applying Detailed Kinetics to Realistic Engine Simulation: The Surrogate Blend Optimizer and Mechanism Reduction Strategies,” SAE J. Engines 3 (1), pp. 241–259; Naik , 2010, “Modeling the Detailed Chemical Kinetics of Mutual Sensitization in the Oxidation of a Model Fuel for Gasoline and Nitric Oxide,” SAE J. Fuels Lubr. 3 (1), pp. 556–566; and Puduppakkam , 2009, “Combustion and Emissions Modeling of an HCCI Engine Using Model Fuels,” SAE Technical Paper No. 2009-01-0669), we identified some common issues in the predictive nature of the mechanisms that are associated with inadequacies of the core (C0 -C4 ) mechanism, such as inaccurate predictions of laminar flame speeds and autoignition delay times for several fuels. This core mechanism is shared by all of the mechanisms for the larger hydrocarbon components. Unlike the reaction paths for larger hydrocarbon fuels; however, reaction paths for the core chemistry do not follow prescribed reaction rate-rules. In this work, we revisit our core reaction mechanism for saturated fuels, with the goal of improving predictions for the widest range of fundamental experiments. To evaluate and validate the mechanism improvements, we performed a broad set of simulations of fundamental experiments. These experiments include measurements of ignition delay, flame speed and extinction strain rate, as well as species composition in stirred reactors, flames and flow reactors. The range of conditions covers low to high temperatures, very lean to very rich fuel-air ratios, and low to high pressures. Our core reaction mechanism contains thermochemical parameters derived from a wide variety of sources, including experimental measurements, ab initio calculations, estimation methods and systematic optimization studies. Each technique has its uncertainties and potential inaccuracies. Using a systematic approach that includes sensitivity analysis, reaction-path analysis, consideration of recent literature studies, and an attention to data consistency, we have identified key updates required for the core mechanism. These updates resulted in accurate predictions for various saturated fuels when compared to the data over a broad range of conditions. All reaction rate constants and species thermodynamics and transport parameters remain within known uncertainties and within physically reasonable bounds. Unlike most mechanisms in the literature, the mechanism developed in this work is self-consistent and contains chemistry of all saturated fuels.

Copyright © 2012 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 1

Comparison of predicted hydrogen/air and hydrogen-O2-Ar flame speeds at 1 atm and 298 K, with the experimental data of Dowdy [53], Kwon [54], Aung [55], Tse [56], Vagelopoulos [57] and Verhelst [58]

Grahic Jump Location
Figure 2

Comparison of predicted hydrogen/air extinction strain rates at 1 atm and 298 K, with the experimental data of Dong [30] and the recent data from Park [31]

Grahic Jump Location
Figure 3

Effect of pressure on ignition-delay times for stoichiometric hydrogen- oxygen-argon mixtures (91.2 mol% argon). Calculated values are compared with the experimental data of Herzler [32].

Grahic Jump Location
Figure 4

Calculated profiles of CH2 O and CO compared with the experimental data of Li [6] during oxidation in a flow reactor at 948 K and 1.5 atm pressure using a mixture of CH2 O/O2 /H2 O:0.0103/2/0.37 mol% in N2

Grahic Jump Location
Figure 5

Calculated flame speeds of methane-air mixtures at 1 atm and 298 K, compared with the data of Vagelopoulos [59] and Van Maaren [60]

Grahic Jump Location
Figure 6

Effect of pressure on ignition-delay times for a methane-oxygen-nitrogen mixture (20 mol% methane) with equivalence ratio of 3. Calculated values are compared with the experimental data of Petersen [34] (data extracted from another Petersen reference [35]).

Grahic Jump Location
Figure 7

Calculated methanol species profiles for oxidation conditions of a methanol-oxygen-nitrogen mixture, compared with the experimental data of Dayma [36]. Conditions include 10 atm, inlet temperatures of 700–1100 K, and an equivalence ratio of 0.6. The inlet species included 8000 ppm of CH3 OH, 20,000 ppm of O2 and 800 ppm of H2 O.

Grahic Jump Location
Figure 8

Calculated flame speeds of ethanol-air mixtures at 1 atm, compared with the data of Egolfopoulos [61], Gulder [62], and Liao [63] at various temperatures

Grahic Jump Location
Figure 9

Calculated flame speeds of dimethyl ether (DME)-air mixtures at 1 atm and 295 K, compared with the data of Qin [37], Daly [64], and Zhao [65]

Grahic Jump Location
Figure 10

Comparison of predicted species temporal profiles with those measured for oxidation of 3030 ppm DME in oxygen-nitrogen mixture, compared with the flow-reactor experimental data of Curran [38] at 12.5 atm and equivalence ratio of 1.19

Grahic Jump Location
Figure 11

Comparison of predicted autoignition times for a stoichiometric DME-air mixture at different pressures with those measured in a shock-tube by Pfahl [39]

Grahic Jump Location
Figure 12

Calculated flame speeds of ethane-air mixtures at 298 K and at various pressures of 1, 2 and 5 atm, compared with the data of Jomaas [40] and Vagelopoulos [41]

Grahic Jump Location
Figure 13

Calculated C2 H6 , C2 H4 and C2 H2 species profiles for ethane pyrolysis (250 ppm ethane in argon), compared with the experimental data of Tranter [42], at 340 bar. Two lines represent predictions with residence times of 1.25 and 1.6 ms due to uncertainty in the measurement.

Grahic Jump Location
Figure 14

Ignition times at 10 atm for stoichiometric ethane-O2 -Ar. Calculated values are compared with the experimental data of Burcat [43].

Grahic Jump Location
Figure 15

Calculated flame speeds of propane-air mixtures at 298 K and at pressures of 1, 2, and 5 atm, compared with the data of Jomaas [40] and Vagelopoulos [41]

Grahic Jump Location
Figure 16

Comparison of predicted flame speeds of n-butane-air with the experimental data of Davis [44] at 1 atm and 298 K

Grahic Jump Location
Figure 17

Comparison of predicted ignition-delay times of a stoichiometric n-butane/O2 mixture, and 81.25 mol% Ar dilution, at 8 atm with those measured by Healy [45]

Grahic Jump Location
Figure 18

Effect of changing equivalence ratio (φ) on ignition-delay times of n-butane/air mixtures at a constant pressure of 20 atm. The data of Healy [45] are compared with the model predictions.

Grahic Jump Location
Figure 19

Effect of changing pressures on ignition-delay times of iso-butane/air mixtures at a constant equivalence ratio of 0.3. The data of Healy [45] are compared with the model predictions.

Grahic Jump Location
Figure 20

Effect of changing pressures on ignition-delay times of stoichiometric mixture of iso-butane/air. The data of Healy [45] are compared with the model predictions.

Grahic Jump Location
Figure 21

Ignition-delay times of Healy [46] compared with model predictions, for iso-butane/air mixtures. Pressures of 1.5, 8 and 20 atm were studied, for a constant equivalence ratio of two.

Grahic Jump Location
Figure 22

Calculated flame speeds of n-butanol-air mixtures at 1 atm and 343 K, compared with the data of Veloo [47]

Grahic Jump Location
Figure 23

Comparison of predicted autoignition time with that measured by Moss [48] for n-butanol-O2 -Ar mixtures in a shock tube at equivalence ratio of 0.25 and nominal pressure of 1 atm

Grahic Jump Location
Figure 24

Comparison of predicted autoignition time with that measured by Moss [48] for n-butanol-O2 -Ar mixtures in a shock tube at stoichiometric conditions and nominal pressure of 1 atm

Grahic Jump Location
Figure 25

Comparison of predicted autoignition time to that measured by Black [49] for n-butanol-O2 -Ar mixtures in a shock tube at equivalence ratio of 1 and nominal pressure of 2.6 atm

Grahic Jump Location
Figure 26

Effect of equivalence ratio (φ) on autoignition times of n-butanol-O2 -Ar mixture with 0.6% fuel at nominal pressure of 8 atm. The data of Black [49] are compared with the model predictions.

Grahic Jump Location
Figure 27

Comparison of predicted species profiles to that measured by Dagaut [50] for oxidation of 1 mol% n-butanol in O2 and N2 in a stirred reactor at equivalence ratio of 1.0, 10 atm, and residence time of 0.7 s. Closed symbols are experimental data and lines with open symbols are predictions.

Grahic Jump Location
Figure 28

Comparison of predicted species profiles to that measured by Dagaut [50] for oxidation of 1 mol% n-butanol in O2 and N2 in a stirred reactor at equivalence ratio of 1.0, 10 atm, and residence time of 0.7 s. Closed symbols are experimental data and lines with open symbols are predictions.

Grahic Jump Location
Figure 29

Comparison of predicted effect of pressure on NO levels in methane-oxygen-nitrogen burner-stabilized flames at unburned mixture temperature of 300 K at various equivalence ratios (φ) to those measured by Thomsen [52]. Oxidizer used is rich in oxygen with nitrogen/oxygen ratio of 2.2/1. CHEMKIN-PRO simulation includes the effect of radiation.

Grahic Jump Location
Figure 30

Sensitivity analysis of laminar flame speed at 298 K, 1 atm, and equivalence ratio of 1.1 for various saturated core components

Grahic Jump Location
Figure 31

Temperature sensitivity analysis for methane-air autoignition under shock-tube conditions of Petersen [34] at equivalence ratio of 3, 140 atm, 1400 K, and 10% conversion

Grahic Jump Location
Figure 32

Reaction path diagram for dimethyl ether under the shock-tube conditions of Pfahl [39], as shown in Fig. 1. The initial conditions included temperature of 850 K, pressure of 40 atm, equivalence ratio of 1.0, and the reaction path diagram is at 20% fuel conversion. Branching ratios are shown in percentage.

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In