Tutorials Manual

Chapter 2: Combustion in Gas-phase Processes
Tutorials Manual
Figure 2-6
Autoignition for Hydrogen/Air—Sensitivity Coefficients
2.3.3 Ignition-delay Times for Propane Autoignition
2.3.3.1 Project Description
This user tutorial presents an ignition-delay time calculation for the homogeneous,
isobaric, adiabatic combustion of propane in air. The ignition times are computed
using two distinct definitions. Discrepancies between results are presented.
Premixed combustion technology is well established in the gas turbine industry. One
of the major concerns of such technology, however, is avoiding the autoignition
phenomenon to protect combustor components as well as to limit levels of pollutant
emissions. Numerical predictions of the ignition time can be very useful in
understanding the autoignition parameters, which can be important for the automotive
and turbine industries. Chemical kineticists can also benefit from predicting ignition
times. Work in validation and testing of detailed mechanisms as well as reduction of
detailed mechanisms often requires analyzing ignition times. One of the better-known
validation techniques for detailed chemical kinetic mechanisms consists of comparing
computational predictions of the ignition-delay times to shock-tube experiments 4, 5, 6 .
Such comparisons can provide a good understanding of the underlying chemistry,
since the 0-D computations are free from transport effects.
4. Reaction and Ignition Delay Times in Oxidation of Propane, B.F. Mayers and E.R. Bartle,
AIAA Journal, V.7, No10, p.1862
5. Validation of Detailed Reaction Mechanisms for Detonation Simulation, E. Schultz and
J. Sheperd, Explosion Dynamics Laboratory Report FM99-5, California Institute of
Technology, Pasadena, CA, February 8,2000
6. A Small Detailed Chemical-Kinetic Mechanism for Hydrocarbon Combustion, M.V.
Petrova and F.A. Williams, Combustion and Flame, Volume 144, Issue 3, February
2006, p. 526
RD0411-C20-000-001 27 © 2007 Reaction Design