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论文类型：期刊论文

发表时间：2014-01-01

发表刊物：ADVANCED POWDER TECHNOLOGY

收录刊物：SCIE、EI

卷号：25

期号：1

页面范围：274-280

ISSN号：0921-8831

关键字：Second-order moment gas-particle two-phase turbulent model; Momentum transfer coefficient; Particle dispersion; Downer; Numerical simulation

摘要：A modified momentum transfer coefficient of dense gas-particle two-phase turbulent flows is developed and its effect on particle dispersion characteristics in high particle concentration turbulent downer flows has been numerically simulated incorporating into a second-order moment (USM) two-phase turbulent model and the kinetic theory of granular flow (KTGF) to consider particle-particle collisions. The particle fractions, the time-averaged axial particle velocity, the particle velocities fluctuation, and their correlations between gas and particle phases based on the anisotropic behaviors and the particle collision frequency are obtained and compared using traditional momentum transfer coefficients proposed by Wen (1966), Difelice (1985), Lu (2003) and Beetstra (2007). Predicted results of presented model are in good agreement with experimental measurement by Wang et al. (1992). The particle fluctuation velocity and its fluctuation velocity correlations along axial-axial and radial-radial directions have stronger anisotropic behaviors. Furthermore, the presented model is in a better accordance with Lu's model in light of particle axial velocity fluctuation, particle temperature, particle kinetic energy and correlations of particle-gas axial-axial velocity fluctuation. Also, they are larger than those of other models. Beetstra's model is not suitable for this downer simulation due to the relative lower particle volume fraction, particle collision and particle kinetic energy. (C) 2013 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.