LES of Delft-Jet-In-Hot-Coflow (DJHC) with tabulated chemistry and stochastic fields combustion model

Abstract

In this work, a turbulent combustion model based on tabulated chemistry and stochastic fields model for turbulence chemistry interaction is applied to a lifted flame studied experimentally at Delft University, which emulates MILD combustion behavior. The experimental set-up consists of a jet of natural gas jet injected into a coflow of lean combustion products mixed non-uniformly with ambient air. The model used in this work has been extended to consider the non-homogeneous co-flow, by introducingan extra conserved scalar for the air stream. The model predicts the lift-off height satisfactorily and also captures the effect of reduced lift-off height with increasing jet Reynolds number. The LES results support the argumentation that the reason for the decrease in the lift-off height is due to enhanced entrainment of the vitiated co-flow into the jet, leading to increased reaction rates and lower autoignition delays. The combustion model shows potential to be used for MILD combustion regime and confirms its capability to be extended to multi-stream mixing cases. This feature makes the model suitable for complex industrial applications for low emission combustion.