离散单元法数值研究水平管中密相栓流气力输送

在对密相栓流气力输送过程中气固两相运动的特点和气固两相流的数值模拟方法进行分析的基础上,将广泛应用于岩土力学中的离散单元法引入以模拟多个颗粒之间长时间的相互作用,同时考虑颗粒与流体间的相互作用(双向耦合),建立了密相栓流气力输送过程中两相流的数学模型.对多个栓的密相栓流气力输送过程进行数值模拟,结果再现了栓的滑落、形成和运动过程,与实验观察到的现象基本一致,预示离散单元法在密相气固两相流数值模拟研究中具有广阔的应用前景,为密相栓流气力输送的进一步研究提供了基础.

Simulation of Dense Phase Pneumatic Conveying of Slug Flow in Horizontal Pipe with Distinct Element Method (DEM)

Based on the analysis of dense phase slug-flow pneumatic conveying in a horizontal pipe and the discussion of numerical simulation method for gas-particle two phase flow, a numerical model of slug flow in a horizontal pipe was built up, in which the Distinct Element Method (DEM) widely applied in rock mechanism was introduced for calculation the contact forces between particles. With the model proposed the normal Eulerian-Lagrangian model for dilute gas-particle system was used to simulate the dense gas-particle system, and the gas motion was expressed by locally averaged Navier-Stocks equation, in which the coupling effect between gas and particle phase was also considered. The motion of multi-slug and the flow of gas were solved simultaneously and the results give realistic pictures of the collapses, formation, development of slugs for the multi-slug flow in horizontal pipe which are essentially the same as those observed in the experiments. It indicates that the Distinct Element Method may be used as a powerful tool for the simulation of the dense phase gas-solid or liquid-solid flow.