CFD Simulation Of Two Phases Flow In Bubble Column

In this thesis, the CFD (computational fluid dynamics) is used to simulate the fluid behaviors in the countercurrent bubble column with Euler-Euler multiphase model. The effect of different superficial gas and liquid velocities on the gas holdup and liquid velocity distributions is investigated.The mixing characteristic is studied at last through the pulse tracer injection techniques.Euler-Euler multiphase model is based on the continuum medium hypothesis. According to the fluid flow in bubble column, the continuum medium model is used to build the equations of the two phases flow.The interphase terms of the equations and the turbulence model are discussed.In the flow behaviors simulation, the gas holdup discreases from the center of the column to near the wall, and it increases when the superficial gas velocity increases. The liquid reverses where the gas holdup is high. The superficial gas velocity affects the reversed liquid velocity, but the superficial liquid velocity determines the area of liquid reversed.Moreover, researches on its axial mixing characteristic have been conducted by using backmixing model to regress the RTD curves which are attained in CFD simulation. The Pe number decreases with the increase of superficial gas velocity, but increases with the increase of the superficial liquid velocity.