Multiphysics Simulations of Entrained Flow Gasification. Part Ⅰ: Validating the Nonreacting Flow Solver and the Particle Turbulent Dispersion Model

摘要

In this two-part paper, we describe the construction, validation, and application of a multiscale model of entrained flow gasification. The accuracy of die model is demonstrated by (1) rigorously constructing lad validating the key constituent submodels against relevant canonical test cases from the literature and (2) validating the integrated model against experirnental data from laboratory scale and commercial scale gasifiers. In part I, the flow solver and particle turbulent dispersion models are validated against experimental data from nonswirling flow and swirling flow test cues in an azisymmetric sudden expansion geometry and a two-phase flow test case in a cylindrical bluff body geometry. Results show that while the large eddy simulation (LES) performs best among all tested models in predicting both swirling and nonswirling flows, me shear stress transport (SST) k-ω model is the best choice among the commonly used Reynolds-averaged Navier-Stokes (RANS) models. The particle turbulent dispersion model is accurate enough in predicting particle trajectories in complex turbulent flows when the underlying turbulent flow is well predicted. Moreover, a commonly used modeling constant in the particle dispersion model is optimized on the basis of comparisons with particle-phase experimental data for the two-phase flow Muff body case.