颗粒性质对叶片圆盘泵叶轮内颗粒分布的影响

Influence of Particle Characteristics on the Distribution of Solid Particles in the Disk Impeller with Radial Straight Blade

为研究颗粒性质对颗粒在叶片圆盘泵叶轮内分布规律的影响,将叶片圆盘泵叶轮分为无叶区和叶片区,采用多重参考坐标系法模拟流体在叶片区和无叶区内的流动。采用Eulerian多相流模型、RNG k-ε湍流模型与SIMPLEC算法,利用Fluent软件对叶片圆盘泵内固液两相湍流进行数值模拟。对不同直径、不同浓度及不同密度颗粒在叶轮叶片区和无叶区的分布及颗粒在叶轮表面分布规律进行分析。结果表明:颗粒密度和颗粒直径对颗粒分布影响较大,颗粒密度、粒径越大,颗粒越难被液相带动加速而处在液相相对速度较慢的无叶区,随着颗粒密度、粒径的增大,叶轮表面颗粒浓度分布变化趋缓;颗粒浓度对颗粒在无叶区和叶片区分布影响较小;叶片表面颗粒浓度大于轮盘表面颗粒浓度,从动轮上轮盘表面和叶片表面颗粒浓度要小于相应主动轮表面颗粒浓度。

To study influence of particle characteristics on the distribution of solid particles in bladeless zone and blade zone of the disk impeller with radial straight blade, impeller was divided into bladeless zone and blade zone. The multiple reference frames （MRFs） approach was used to simulate impeller rotation in pump casing. Three-dimensional simulation was performed for the solid-liquid two-phase turbulent flow in disc pump by using Fluent software with Eulerian model, extended SIMPLEC algo- rithm and RNG k - ε turbulence model. The concentration distribution of solid particles with different diameters and different vol- ume fractions and different specific gravities were achieved, and particle concentration distribution along impeller surface was cal- culated. The further analysis of the solid particles distribution indicates that particle specific gravity and particle diameter, which are the characteristics of solid particles, has more influence on the distribution of solid particles, particles with larger specific gravity and diameter were easier to move to the point of highest velocity-relative to the discs and lowest pressure, i. e. , the cen- tral space between the discs by the difficulty to be carried and accelerated. The volume fraction also has less effect on the particle distribution in bladeless zone and blade zone of the disk impeller. Particle concentration of blade surface is morer than that of im- peller plate surface and particle concentration of driven impeller is less than that of driving impeller.