旋流分离器内三维两相流场的数值模拟

Numerical simulation of three-dimensional two-phase flow in hydrocyclone

采用RNG k-ε湍流模型,对旋流分离器内三维两相流场作了数值模拟,给出了压力、速度、湍流动能和湍流耗散率等参数的分布。结果表明流体速度从中心沿径向逐渐增大,在旋流器壁面附近又逐渐降低,湍流动能、湍流强度以及湍流粘度均沿径向先增大然后逐渐减小,而湍动能耗散率的变化是沿径向先增大然后逐渐减小,在壁面附近急剧增大。同时对不同粒径颗粒的运动轨迹进行了计算和讨论。计算结果表明,粒径较大的颗粒大多进入到底流口,而粒径较小的颗粒大多进入到顶部溢流口。而粒径为100μm的固体颗粒100％进入底流,与从进口面不同点进入无关。

RNG k-ε turbulence model was used to simulate the 3-D two-phase flow in the hydrocyclone. The distributions of the pressure, velocity, turbulent kinetic energy, turbulent dissipation rate, turbulence intensity and turbulent viscosity were presented. Numerical results show that the velocity increases with the radius and decreases near the wall of the hydrocyclone. The turbulent kinetic energy, turbulence intensity and turbulent viscosity increase with the radius first, then decrease. But the turbulent dissipation rate increases with the radius first, then decreases, and increases sharply near the wall. The particle trajectories were also calculated. Computational results show that most of the bigger particles enter into the underflow and the smaller particles enter into the overflow. All the particles with a diameter of 100 μm enter into the underflow and it＇s independent of the point of the inlet through which they enter into the hydrocyclone.