AUSM turbulence-chemistry model for simulating NO formation in swirling coal combustion

An algebraic unified second-order moment (AUSM) turbulence-chemistry model was proposed for simulating NO formation during coal combustion. A full two-fluid model together with the κ-ε-κ_p two-phase turbulence model, the EBU-Arrhenius combustion model, the six-flux radiation model and two different turbulence-chemistry models of NO formation were used to simulate gas-particle flows, coal combustion and NO formation in a swirl burner. The predicted two-phase flow results are in good agreement with the PDPA (phase-Doppler particle anemometer) measurement results. Comparison of predicted combustion results with experiments indicates that the AUSM model is more reasonable than the original ASM model, which under-predicts the NO formation rate due to the approximation made in series expansion of the exponential function of temperature. So does the simulation of NO formation during methane-air combustion by using the original ASM model reported in other documents.