Further Development of Eddy Dissipation Model for Turbulent Non-Premixed Combustion Simulation

Abstract

In view of the application limits of the modified eddy dissipation model (MEDM) in simulations of weakly turbulent flow, compressible flow, and internal flow, an improved eddy dissipation model (IEDM) is proposed. The IEDM model uses the dissociation reactions to obtain the correct combustion temperature instead of the specific heat compensation used in the MEDM model. This extends the application in compressible flow simulation. The simulation accuracy of the IEDM model for weakly turbulent flow is improved by using the accurate transport property and model. The maximum ε/k is limited to give a reasonable reaction rate near walls, and the expression for the model parameter A is also updated. Nine turbulent flames including seven jet flames and two opposed jet flames are simulated with the improved model. Compared with the experimental data of the jet flames, the peak temperature differences with the MEDM model and the IEDM model are 189 and 161 K, respectively, indicating the minor accuracy improvement of the IEDM model. Compared with the experimental data of the opposed flames, the peak temperature differences with the MEDM model and the IEDM model are 131 and 7 K, respectively, indicating the significant accuracy improvement of the IEDM model.

Keywords

• eddy dissipation model
• modified eddy dissipation model
• improved eddy dissipation model
• turbulent combustion model
• turbulent non-premixed flame