Assessment of a three-variable reduced kinetic scheme in prescribed turbulence
- General Electric Corporate R&D Cent, Schenectady, NY (United States)
A chemical kinetic scheme for the combustion of complex hydrocarbon fuels is developed and assessed at conditions typical of high-intensity turbulent combustion. In the starting scheme, the fuel is assumed to pyrolyze at a global rate to CO and H2, which subsequently are oxidized in a series of elementary steps. The reduced scheme requires three variables: the mixture fraction xi, the fuel mass fraction Y(f), and a combined variable Y for CO and H2. The oxyhydrogen radical pool is assumed to be in a state of partial equilibrium, and the CO and H2 burn out as the radical pool decays via recombination reactions. The reduced scheme is compared with the starting scheme on combustion stability and CO/UHC emissions, in the context of the `partially stirred reactor` (PaSR) model developed earlier. The conditions are 30 atm, 1000 K inlet temperature, 2500 K equilibrium temperature (premixture equivalence ratio = 0.8), and 5 ms reactor residence time (in the perfectly stirred reactor (PSR) limit). PaSR simulations are conducted in the range 10-1000 Hz (mixing frequency), and in each case converge to a stochastic steady state and span the plug flow reactor-PSR limits smoothly. The reduced scheme performs well on flame stability (temperature) and fuel mass fraction, but not as well on CO and H2, because the partial equilibrium assumption breaks down under conditions where significant amounts of fuel are present. Since only three variables are needed, the scheme is computationally fast enough for use in computational fluid dynamic studies of high-intensity turbulent combustion. 19 refs.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 117651
- Journal Information:
- Journal of Propulsion and Power, Journal Name: Journal of Propulsion and Power Journal Issue: 3 Vol. 11; ISSN 0748-4658; ISSN JPPOEL
- Country of Publication:
- United States
- Language:
- English
Similar Records
Parallel simulations of partially stirred methane combustion
A priori examination of reduced chemistry models derived from canonical stirred reactors using three-dimensional direct numerical simulation datasets