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在考虑气-固流体的双向耦合、颗粒与颗粒的碰撞、颗粒与壁面的碰撞以及滑移摩擦的基础上,对气体相湍动能采用修正的k-ε二方程模型,颗粒相湍动动能采用颗粒动力学方法,发展建立了水平气力输送的数学模型和相应的计算方法,数值研究了颗粒粒径和密度对悬浮颗粒的浓度分布的影响。结果发现在水平气力输送中,在颗粒湍动、颗粒自身重力、颗粒与颗粒的碰撞以及颗粒与壁面的碰撞的共同作用下,颗粒浓度分布不均匀,其垂向分布存在着两种不同的形态。颗粒粒径越小、密度越低,越容易出现Ⅰ型分布:即颗粒浓度呈现出从管底部到管上部会先由小变大,到某位置时达最大值,尔后又向小变化的趋势。
On the basis of the bidirectional coupling of gas-solid fluid, particle-particle collision, particle-wall collision and sliding friction, a modified k-ε two-equation model was adopted for the gas phase turbulent kinetic energy. The kinetic energy of particle phase turbulence Particle dynamics method, the mathematical model of horizontal pneumatic conveying and the corresponding calculation method are developed. The influence of particle size and density on the concentration distribution of suspended particles is studied numerically. The results show that in the horizontal pneumatic conveying, the particle concentration distribution is uneven with the turbulence of the particles, the gravity of the particles themselves, the collision between the particles and the particles, and the collision between the particles and the wall. There are two different morphologies of the vertical distribution . The smaller the particle size and the lower the density, the more likely it is to be Type I: the particle concentration shows a tendency that from the bottom of the pipe to the upper part of the pipe first becomes smaller and larger, reaches a maximum at a certain position, and then changes to a smaller one .