鼓泡塔内气泡羽流周期性摆动的数值模拟

以二维和三维鼓泡塔内气液二相流动的动态特性为研究对象,寻找各自合适的湍流模型和边界条件设置。二维鼓泡塔的进口气速采用2种不同的方法:①实际进口速度法;②均值修正法。湍流模型选用标准k-ε湍流模型、RNG k-ε湍流模型。结果显示二维模拟使用RNG k-ε湍流模型、三维模拟使用标准k-ε湍流模型能够得到周期性的羽流摆动,且二维鼓泡塔的进口气速采用均值修正法能够得到较合理的摆动周期。

Numerical simulation of bubble plume periodic oscillation in bubble column

The dynamic characteristic of gas-liquid phases in 2D and 3D bubble columns was taken as a studying object,expecting to find suitable turbulence model and boundary conditions for 2D and 3D simulation.For 2D computation,the inlet velocity conditions were evaluated,i.e.∶ ① the actual inlet velocity of 3D bubble column;② an averaged inlet velocity with diffusion correction.Standard k-ε turbulence model and RNG k-ε turbulence model were used.The numerical results show that 2D simulation using RNG k-ε turbulence model and 3D simulation using standard k-ε turbulence model can mimic the periodic plume oscillations in bubble columns.The results also confirm that the oscillations period can be predicted only when the corrected inlet velocity is employed for 2D simulation.