基于CFD-DEM耦合的条缝出流自由下落流场特性研究

Study on Flow Characteristics of Free Falling from Slit based on CFD-DEM Coupling

采用CFD-DEM耦合模型研究了颗粒条缝出流自由下落过程的流场特性。研究表明,随下落高度增大,在距出流口900 mm处颗粒速度分布趋于一致。远离出口处相同高度不同方向上卷吸空气速度分布基本一致。随出口长度增加,颗粒和卷吸空气速度逐渐增大并在l>30 mm后趋于定值。粒径越大,颗粒速度越大而卷吸空气速度越小。对实际通风除尘设计,卷吸空气量随出口长度增加而增大,但单位质量流量卷吸空气量随之减小。粒径越小,卷吸空气量和单位质量流量卷吸空气量越大。

The CFD-DEM coupled model was used to study the particle field characteristics in the free falling process of granular flow from slit.The results show that the particle velocity distribution tends to be consistent at 900 mm from the outlet as the falling height increases;and the velocity distribution of entrained air in different directions at the same height away from the outlet is basically the same.With the increase of outlet length,the velocity of particles and entrained air increases gradually and tends to be constant after l>30 mm.The larger the particle size,the larger the particle velocity and the smaller the entrainment air velocity.For the actual ventilation and dust removal design,the entrained air volume increases with the length of the outlet,but the entrained air volume per unit mass flow decreases.The smaller the particle size,the larger the entrained air volume and the entrained air volume per unit mass flow.