Computational Fluid Dynamics

Detailed modeling of a gasifier, including microscale modeling of solid conversion and Computational Fluid Dynamics (CFD) modeling of both phases, is needed to define internal operating conditions, failure modes, to optimize designs, etc. FLUENT RANS modeling of the coal gasification process in a pilot-scale entrained flow gasifier has been performed. The predicted results are in reasonable agreement with available experimental data, although further improvements of the heterogeneous reaction model and other submodels are needed. LES reduces the uncertainty associated with using turbulence models in RANS modeling, especially for the highly transient gasifier environment. FLUENT LES modeling of the same gasifier is undergoing. An in-house research code is also being developed for the flow dynamics in entrained flow gasifiers. The code is currently being validated using experimental data for a swirling flow in a cylindrical sudden expansion, which has some of the key features of the flow in entrained flow gasifiers.