表面驻泡颗粒在液相运动中的特征分析

Characteristic Study About the Particle with Gas on the Surface in the Liquid Phase

基于多相流体动力学的贝赛特(Basset)-鲍瑟内斯克(Boussinesq)-奥森(Ossen)方程(BBO方程)研究滑移条件下颗粒在两相流中的运动情况。针对小型浮游生物表面微结构特征建立固-气-液三相双滑移模型,运用Karman边界层动量定理推导出以气相衔接的固-气相和气-液相层流边界层速度分布表达式。通过参数分析法确定Basset力、颗粒所受阻力及附加质量力对颗粒运动的影响,对BBO方程进行简化求解,得到颗粒在流场中的轨迹方程。将本文提出的滑移速度分布代入轨迹方程得到有滑移边界条件下颗粒在流场中的运动速度随时间的变化。通过分析可以得到,颗粒表面的驻泡结构使得颗粒与流场接触界面处出现速度滑移,从而提高了颗粒的运动速度。

In this paper, the movement of particles in two-phase flow under the condition of double slips was studied based on Basset-Boussinesq-Ossen equation. As to the special micro-structure on the surface of the marine-beings, the velocity distributions both in the solid-gas boundary layer and in the gas - liquid boundary layer were deduced with Karman boundary layer momentum theorem. Basset force, added mass force and drag for particles were determined through parameter method. The BBO e- quation was simplified and trajectory equation of particles in flow field was obtained. The slip velocity distribution was put in the particle trajectory equation and the velocity change curve under slip boundary conditions was obtained. The results indicate that the micro bubbles on the particle surface can lead slip within the boundary layer. The flow field velocity near the solid phase can be increased by micro-bubbles and the particle velocity can be increased.