Conditional moment closure calculations of a swirl-stabilized, turbulent nonpremixed methane flame

As natural gas production and usage continues to increase, displacing oil and coal, there is an escalating requirement to ensure that natural-gas burning equipment performs as cleanly and efficiently as possible to allow the environmental advantages of this fuel to be realized. Presented are encouraging results obtained from the three-dimensional, elliptic, CMC modeling of a low-swirl-stabilized nonpremixed flame of methane, which are representative of such technologies. Calculations were based upon the solution of the three-dimensional fluid-flow equations supplemented with a Reynolds stress and scalar flux second-moment closure, and the chemistry applied to represent mean production rates of species was a 16-step reduced mechanism. Predictions of species in both mixture fraction and real space display a level of conformity with experimental data that is encouraging for these methods in both a qualitative and a quantitative sense. Shortcomings of the modeling procedures are discussed in light of the results, and suggestions are made for future investigation.