定常均匀流中颗粒均匀分布的稳定性

Stability of particle distributions in steady uniform flows

在双流体模型的框架下,对定常均匀流中颗粒均匀分布的稳定性进行了分析。给出了颗粒均匀分布的稳定性条件。研究了影响颗粒均匀分布状态稳定性的主控参数及颗粒均匀分布稳定的参数范围。讨论了颗粒碰撞恢复系数、颗粒初始体积分数对颗粒聚集的影响。发现随着颗粒Re的增加,系统将会由稳定状态转变为不稳定状态。在初始的颗粒体积分数小于0.015的情况下,系统对短波扰动是稳定的,对长波扰动是不稳定的。在颗粒初始体积分数高于0.015时,系统对短波扰动是不稳定的,对长波扰动则是稳定的。颗粒碰撞弹性恢复系数越小、颗粒初始体积分数越大,颗粒聚集现象越明显,只有在颗粒浓度小于0.0005的情况下,颗粒才不会出现聚集现象。

The stability of the particle distribution in a steady uniform flow was analyzed using a two-fluid model. The stability conditions were derived as a function of the main control parameters. Analnysis of the effects of particle volume fraction and collision restitution coefficient on cluster formation showed that the system becomes unstable with increasing particle Reynolds number. When particle concentrations less than 0.015 may suppress short wavelength disturbances but will magnify long wavelength disturbances. Particle concentrations greater than 0.015 will magnify short wavelength disturbances but suppress long wavelength disturbances. Clusters more easily form with increasing particle volume fractions and decreasing particle collision restitution coefficient. Clusters always exist unless the particle concentration is less than 0.000 5.