분자확산이 난류 비예혼합 화염구조에 미치는 영향 해석

Abstract

In RANS based turbulent non-premixed flame simulation, the effects of molecular transport are usually neglected. However the molecular transport has a significant effect on the prediction of the upstream mixing layer between the coflow and the piloted stream where the turbulence level is weak. In present study, the multi-environment probability density function model has beenapplied to simulate the turbulent piloted non-premixed flames. The direct quadrature method of moments (DQMOM) has been adopted to solve the transport PDF equation due to its computational efficiency and robustness. The IEM mixing model is employed to represent the mixing process and the chemical mechanism is based on Gri 3.0 mechanism. To account for the molecular transport, the scalar mixing frequency is modified. Numerical results obtained in this study are precisely compared with experimental data in terms of unconditional and conditional means for scalar fields.