摘要
为了研究高剪切匀浆泵对物料的剪切混合效果,掌握剪切泵内流场的宏观规律和速度特性,应用三维造型软件Pro/E建立高剪切匀浆泵的水力模型,采用计算流体动力学的数值计算方法,基于Mixture混合模型,扩展的标准k-ε湍流方程及SIMPLEC算法对高剪切匀浆泵进行固液两相流的数值模拟.为了减小网格数量对计算结果的影响,对高剪切匀浆泵进行了网格的无关性检验.对不同流量和转速工况下的高剪切匀浆泵进行了数值模拟及横向比较,分析了流量和转速对剪切泵内流场的影响规律.分析结果表明:物料在经过剪切外腔后混合均匀程度显著提高,说明该剪切泵能对物料起到较好的混合均匀作用;随着流量的增大,固液两相混合均匀化速率变慢;随着转速的增大,两相混合均匀程度及速率变快,但改变转速只对转轮部分有影响,对进口区域的固相体积分数影响不大.
In order to study the mixing effect of flow and analyze the flow pattern as well as the velocity characteristics in high shear pulp pump, a geometrical hydraulic model of a high shear pulp pumps was established by Pro/E, and solid-liquid two-phase flow in it was simulated by using the CFD method based on the mixture model, standard k - e turbulence model and SIMPLEC algorithm. The mesh- independence check was conducted to reduce the influence of mesh size on the results. A series of CFD numerical simulations were carried out under different discharges and rotational speeds, respectively, and the results were compared among the cases to identify their influence on the flow field in the pump. The results show that the mixing uniformity of two phases was improved considerably after the solid phase was sheared in the shearing chamber, suggesting the shear pulp pump exhibited a better mixing and homogenizing effect for the solid phase in flow. The rate of two phases mixing becomes slow when the discharge is increased, and the mixing rate and uniformity of two phases are improved when the rotational speed increases. Note that the mixing rate and uniformity of two phases in the impeller but those in the inlet to the impeller are affected in a great deal by a change in the rotational speed.
出处
《排灌机械工程学报》
EI
北大核心
2012年第4期407-411,441,共6页
Journal of Drainage and Irrigation Machinery Engineering
基金
科技部中小企业技术创新基金资助项目(07C26213401445)
江苏高校优势学科建设工程项目
关键词
高剪切匀浆泵
两相流
剪切混合
计算流体动力学
数值模拟
high shear pulp pump
two-phase flow
shearing and mixing
computaional fluid dynamics
numerical simulation
