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

Laminar Flame Speeds and Strain Sensitivities of Mixtures of H2O2N2 at Elevated Preheat Temperatures

[+] Author and Article Information
J. Natarajan, T. Lieuwen, J. Seitzman

School of Aerospace Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0150

J. Eng. Gas Turbines Power 130(6), 061502 (Aug 22, 2008) (8 pages) doi:10.1115/1.2943180 History: Received January 15, 2008; Revised January 16, 2008; Published August 22, 2008

Laminar flame speeds and strain sensitivities of mixtures of H2 and air or air highly diluted with N2 (O2:N2 1:9) have been measured for a range of equivalence ratios at high preheat conditions (700K) using a nozzle generated, 1D, laminar, wall stagnation flame. The measurements are compared with numerical predictions based on three detailed kinetic models (GRIMECH 3.0 , a H2CO mechanism from Davis (2004, “An Optimized Kinetic Model of H2∕CO Combustion  ,” Proc. Combust. Inst., 30, pp. 1283–1292) and a H2 mechanism from Li (2004, “An Updated Comprehensive Kinetic Model of Hydrogen Combustion  ,” Int. J. Chem. Kinet., 36, pp. 566–575)). Sensitivity of the measurements to uncertainties in boundary conditions, e.g., wall temperature and nozzle velocity profile (plug or potential), is investigated through detailed numerical simulations and shown to be small. The flame speeds and strain sensitivities predicted by the models for preheated reactants are in reasonable agreement with the measurements for mixtures of H2 and standard air at very lean conditions. For H2 and N2 diluted air, however, all three mechanisms significantly overpredict the measurements, and the overprediction increases for leaner mixtures. In contrast, the models underpredict flame speeds for room temperature mixtures of H2 with both standard and N2 diluted air, based on comparisons with measurements in literature. Thus, we find that the temperature dependence of the hydrogen flame speed as predicted by all the models is greater than the actual temperature dependence (for both standard and diluted air). Finally, the models are found to underpredict the measured strain sensitivity of the flame speed for H2 burning in N2 diluted air, especially away from stoichiometric conditions.

FIGURES IN THIS ARTICLE
<>
Copyright © 2008 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 1

Variation of the model (GRIMECH 3.0 : closed symbols; Davis H2∕CO mechanism: open symbols) overprediction with preheat temperature for 50:50 H2:CO fuel composition at 0.6 and 0.8 equivalence ratios

Grahic Jump Location
Figure 2

Schematic of the experimental setup (TC=thermocouple); mixing is achieved through long flow lines

Grahic Jump Location
Figure 3

Measured axial velocity along the stagnation streamline for H2 with N2 diluted air (O2:N2 1:9) mixture at Φ=0.8 and 700K preheat temperature (D=9mm; L=6mm); figure insert shows a layout of the nozzle generated wall stagnation flame (WSF)

Grahic Jump Location
Figure 4

Strained laminar flame speeds for mixture of H2 with air at Φ=0.3 and 700K preheat temperature; data (symbols and linear fits) and OPPDIF predictions (lines)

Grahic Jump Location
Figure 5

Strained laminar flame speeds for mixture of H2 with air at Φ=0.5 and 700K preheat temperature; data (symbols and linear fits) and OPPDIF predictions (lines)

Grahic Jump Location
Figure 6

Strained laminar flame speeds for mixture of H2 with N2 diluted air (O2:N2 1:9) at Φ=0.8 and 700K preheat temperature; data (symbols, dashed linear and solid nonlinear fits) and OPPDIF predictions (lines)

Grahic Jump Location
Figure 7

Strained laminar flame speeds for stoichiometric and rich mixtures of H2 with N2 diluted air (O2:N2 1:9) at 700K preheat temperature; data (symbols and linear fit) and OPPDIF predictions (lines)

Grahic Jump Location
Figure 8

Ratios of the models predicted (PREMIX ) and measured unstrained laminar flame speeds for lean mixtures of H2 with standard air at 300K and 700K preheat temperatures

Grahic Jump Location
Figure 9

Ratios of the models predicted (PREMIX ) and measured unstrained laminar flame speeds for lean mixtures of H2 with H2 with N2 diluted air at 300K and 700K preheat temperatures

Grahic Jump Location
Figure 10

Numerical simulation of CFF and WSF for H2 with N2 diluted air (O2:N2 1:9) at Φ=0.8 and 700K preheat temperature

Grahic Jump Location
Figure 11

Model predicted strained flame speeds for CFF and WSF with two different wall temperatures. The fuel mixture is H2 with N2 diluted air (O2:N2 1:9) at Φ=0.8 and 700K preheat temperature. The vertical bars indicate 3% deviation from CFF.

Grahic Jump Location
Figure 12

Numerical simulation of stagnation flame with plug and potential flow boundary conditions for the same strain rates. The fuel mixture is H2 with N2 diluted air (O2:N2 1:9) at Φ=0.8 and 700K preheat temperature.

Grahic Jump Location
Figure 13

Model predicted strained flame speeds with plug and potential flow boundary conditions. The vertical bars indicate 2% deviation.

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