微重力量值对气液两相流相分布及液相湍流统计量影响的数值研究

气液两相流在空间领域具有广阔的应用前景, 深入理解微重力量值(微重力大小)对相分布和液相湍流的影响十分必要. 采用欧拉elax-elax拉格朗日双向耦合模型深入研究了不同微重力量值对相分布和液相湍流的影响. 液相速度场通过直接数值模拟求解, 气泡的运动轨迹由牛顿运动方程跟踪. 研究表明, 气泡分布和液相湍流与微重力量值均具有直接联系. 在低微重力量值下, 气泡近似均匀分布在槽道内, 且对液相湍流统计量几乎没有影响; 然而当微重力量值较高时, 大量气泡聚集在壁面附近, 液相湍流由于气泡的注入受到极大调制. 

Numerical Investigation on Influence of Micro-gravity Magnitude on Phase Distribution and Liquid Turbulence Statistics in Bubbly Flow

In view of a wide application prospect of bubbly flows in space,it is necessary to deeply understand the influence of microgravity magnitude on the phase distribution and liquid turbulence. An Euler-Lagrange model was developed and used to investigate the influence of the microgravity magnitude on the phase distribution and liquid turbulence.The velocity field of liquid was solved by Direct Numerical Simulations(DNS),and the bubble trajectories were tracked by Newtonian equation of motion.The results show that the bubble distribution and liquid turbulence have a direct relation with the microgravity magnitude.For the computational case with a relatively low gravity magnitude,bubbles roughly uniformly disperse in the channel,and the injection of bubbles has almost no influence on the liquid turbulence.However,when the gravity magnitude is relatively high,most of bubbles accumulate near the wall,and the liquid turbulence is greatly modulated due to the injection of bubbles.