Direct Numerical Simulation and Second-Order Conditional Moment Closure Modelling of a Turbulent Hydrocarbon Flame
난류 탄화수소화염의 직접수치해석 및 이차 조건모멘트닫힘 모델링
- Kim, Seung-Hyun ;
-
Huh, Kang Y.
;
- Bilger, Robert W. (School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney)
- Published : 2001.11.16
Abstract
A second-order conditional moment closure(CMC) model is applied to the prediction of local extinction in a turbulent hydrocarbon diffusion flame and compared with direct numerical simulation(DNS) results for the flame. Combustion of a hydrocarbon fuel is described by a simple two-step mechanism. A second-order correction for conditional mean reaction rate terms is made by the assumed pdf method. The results show that the second-order closure is necessary for accurate prediction of intermediate species, while first-order CMC gives good predictions for fuel, oxidant, product and temperature. Conditional variances and covariances are well predicted during an extinction process while they are overpredicted during a reignition process.