基于双流体模型的流化床模拟

从单相流体力学中描述气体流动的Navier-Stokes方程和单颗粒运动的Newton方程出发,使用比较严格的体积平均法推导出描述气固两相宏观流动的模型方程组并设法确定了模型参数,把该方程组加以简化,能得到Gidaspow、Blake和Davidson等人的模型方程,初步证明了模型的正确性,求解使用了经本文改进的基于控制容积有限差分的IPSA方法,编制了通用程序,模拟了二维射流流化床中浓密气固两相的流动,并计算出射流的穿透深度。

SIMULATION OF FLUIDIZED BED USING TWO-FLUID MODEL

The two - fluid model equations describing gas and solid flow macroscopically in a dense fluidized bed were derived from the well known Navier - Stokes equations of the gas and the Newtonian equations of a single particle using the rigorous volume - averaging method. Four parameters of the model equations were obtained. The model equations could be simplified to Gidaspow's, Blake's and Davidson's equations, which verified our two - fluid model equations tentatively. The model equations were solved by means of the modified IPSA technique based on finite - volume method. Numerical computations were made for the gas and solid flow in a two - dimensional jet fluidized bed containing fine sand, millet or binary mixture (fine sand and ash -agglomerate). The numerical results are in good agreement with experimental and reported data in the literature.