Numerical Study of Non-premixed MILD Combustion in DJHC Burner Using Eddy Dissipation Concept and Steady Diffusion Flamelet Approach

摘要

Numerical study simplifies the challenges associated with the study of moderate and intense low oxygen Dilution (MILD) combustion. In this study, the numerical investigation of turbulent non-premixed combustion in a Delft Co-flow Burner presents, which emulates MILD combustion behaviour. MILD combustion yields high thermal and fuel efficiency along with very low emission of pollutants. Using commercial ANSYS software, this study focuses on assessing the performance of two different turbulent-chemistry interactions models: a) Eddy Dissipation Concept (EDC) with reduced chemical kinetic schemes with 22 species (DRM 22) and b) Steady Diffusion Flamelet model, which is adopted in the Probability Density Function (PDF) approach method using chemical kinetic schemes GRI mech 3.0. The results of numerical simulations are compared with available experimental data measurement and calculated by solving the k-epsilon realizable turbulence model for two different jet fuel Reynolds numbers of 4100 and 8800. It has observed that the Steady Diffusion Flamelet PDF model approach shows moderately better agreement with the predicting temperature fields of experimental data using chemical Mechanism GRI mech 3.0 than the EDC model approach with a chemical mechanism with DRM 22. However, both models perform a better understanding for predicting the velocity field with experimental data. The models also predict and capture the effects of lift-off height (ignition kernel) with increasing of fuel jet Reynolds number, Overall, despite having more computational cost, the EDC model approach with GRI mech 3.0 yields better prediction. These featured models are suitable for the application of complex industrial combustion concentrating low emission combustion.