采用两相流混合模型,选取RNG k-ε湍流模型封闭两相流时均方程,对辐流式二次沉淀池液固两相流力学特性进行三维数值模拟。采用有限体积法求解微分方程；紊动能、紊流耗散均采用Quick离散格式；速度与压力耦合求解时使用了压力隐式算子分裂PISO(Pressure-Implicit with Splitting of Operators)算法。通过模拟获得了速度场、紊动能和污泥质量浓度等参量在空间的分布规律,对沉淀池的设计有一定的参考价值。
英文摘要:
The two-phase mixture model was used to study the mechanical feature of solid-liquid two-phase turbulent flow in a secondary sedimentation tank of radial flow by 3-D numerical simulation .The improved RNG two-equation turbulent model was used to close the two-phase time-averaged equations. The finite volume method was used to solve the differential equations; the turbulence kinetic energy and the kinetic energy of turbulent dissipation took quick discrete format; the coupling velocity and pressure equations were solved with PISO algorithm(pressure-implicit with splitting of operators).Through simulation, the paper obtained the distribution law of velocity field, turbulent kinetic energy ,and quality concentration of sludge in apace, which has certain reference value for the design of secondary sedimentation tank.