一个用于模拟分相湍流扩散的粒子与湍流涡作用时间模型

In gas-liquid bubbly flow, due to marked density difference between gas and liquid phases, some no-drag forces, such as virtual mass force, pressure gradient force, etc., may become important. In this case, the effect of these no-drag forces on the turbulent dispersion of gas bubble should be considered. The eddy lifetime (EL) model wasn’t fully applicable to stirred tank because of high non-homogeneous turbulence. In this work, based on the analysis of forces exerted on gas bubble, we obtained an eddy-bubble interaction (EBI) model, which coupled the effect of no-drag forces and used the eddy-bubble interaction time as the renew time scale. The relationship of crossing time and eddy lifetime was discussed, and the radial, axial velocities and gas holdup distribution predicted by the EBI and EL models were also compared with the experimental data, we found that the crossing time showed obviously different from the eddy lifetime, the crossing time may be much smaller than the eddy lifetime in some positions and the predicted gas holdup distribution showed a better agreement with the experiment data than that predicted by the EL model.