Temporally and spatially resolved calculations of a reacting coal jet using large eddy simulations (LES) and direct quadrature method of moments (DQMOM)

In a turbulent combusting coal jet, accurate prediction of the particle and velocity distributions are critical for predicting flame characteristics and ultimately heat flux in a coal-fired boiler. The present work combines a state-of-the-art particle model and turbulent-reacting flow model to provide a realistic simulation of the near burner region of a coal injector. The large eddy simulations (LES) technique is used to represent the turbulent coal jet the direct quadrature method of moments (DQMOM) is used to represent the particle phase. DQMOM provides an Eulerian particle-tracking method with full statistics. When, combined with the spatial and temporal resolution provided by LES, DQMOM yields a comprehensive statistical description of the behavior of the particle phase in the jet. Results are presented for a coal devolatilization experiment. Three key particle behaviors are note; particle segregation, particle clustering, and particle devolatilization. The present work identifies issues relevant to simulating reacting coal jets using LES and DQMOM, and lays the groundwork for future development.