Study of MILD combustion using LES and advanced analysis tools

A cylindrical confined combustor operating under MILD condition is investigated using LES. The combustion and its interaction with turbulence are modeled two reactor based models, PaSR EDC. Results show that the Partially Stirred Reactor (PaSR) model yields improved estimation for mean temperature species mole fractions compared to Eddy Dissipation Concept (EDC). LES data analysed advanced post-processing methods such as chemical Tangential Stretching Rate (TSR), balance analysis local Principle Component (PCA) analysis. TSR can identify explosive (ignition-like) contractive (burnt) regions. With of convective, diffusive reactive terms in equation, regions substantial heat release coming from ignition or flame identified. PCA classifies whole domain into clusters (regions specific features) provides leading each cluster. three analyses correlate well one another it observed most chemically active region locates upstream (in near-field). Also, both autoignition flame-like structures play equally important roles combustion.