颗粒对湍流影响的无量纲分析

Non-Dimensional Analysis of Effects of Particles on Turbulence

气固两相流中颗粒相和气相的相互作用一直是国际多相流领域的研究热点之一,特别是颗粒对湍流的影响吸引了大量研究者的关注。但迄今为止,还没有一个通用的方法能定性判定颗粒是增强湍流还是削弱湍流,更无法准确对颗粒影响下的湍流变动进行定量预测。本文基于无量纲Π定理,对影响气固两相湍流变动的物理量进行无量纲分析,得到了关于湍流变动量的方程。通过对以往研究者实验得到的大量数据进行分析,提出了一个新的无量纲量Lo作为定性判据颗粒增强或削弱湍流的参数,进而利用线性拟合得到了影响湍流变动幅值的函数表达式。

Interaction between dispersed particle phase and carrier gas phase in gas-solid two-phase flows is always one of the research hot topics in the international multiphase flow community. In particular, the effects of particles on turbulence have attracted a lot of attention. But so far, there has not been a general approach to qualitatively determine if particles enhance turbulence or decrease turbulence, and yet unable to accurately quantitatively predict turbulence modulation under the influence of particles. Based on the non-dimensional H theory, the physical variables that influence gas-solid two-phase turbulence modulation have been analyzed, and an equation describing turbulence modulation has been obtained in the present work. By analyzing experimental data from previous researchers, a new non-dimensional quantity Lo is proposed to qualitatively determine if particles enhance turbulence or decrease turbulence, and a functional expression of turbulence modulation influenced by particles is obtained using linear fitting.