中文摘要：

运用基于欧拉–欧拉方法的混合欧拉多相流模型结合雷诺应力湍流模型,对较大雷诺数下的水平固液两相湍流进行了数值计算,主要考察了以Kolmogorov尺度（约为2ν/uτ）为临界值的细小沙粒颗粒在5%的固相体积分数下对湍流场的调制及其减阻效应。研究发现,无量纲颗粒直径dp＋≤2的小颗粒减小了固液两相湍流的雷诺应力,并且三个方向上的速度脉动也被不同程度地削弱;而dp＋=4的大颗粒使缓冲层区域的雷诺应力稍增大,在增强法向速度脉动的同时对流向脉动有抑制作用,并且值得关注的是,较大颗粒的存在导致缓冲层中的部分区域出现了流变现象。在减阻方面,较小的颗粒（dp＋≤2）有大致相同的减阻表现,而大颗粒（dp＋=4）已经失去了减阻性能,总体上看,在所研究的情形下微颗粒的减阻性能随着其粒径的增大而降低。

英文摘要：

The numerical simulations of liquid-solid two-phase turbulent horizontal flow under high Reyn- olds number conditions were performed by using mixture model for multiphase flows, based on Eulerian- Eulerian approach, combined with Reynolds stress model. Turbulence modulation and drag reduction by fine sand particles smaller or larger than the Kolmogorov length scale （about 2u/gr） were investigated with 5% solid volume fraction. It was shown that for smaller particles dimensionless diameter d~ 42 Reynolds stress decreased, and velocity fluctuations in x, y, z-directions were suppressed to some ex- tents~ for the relatively large particles d; = 4 Reynolds stress slightly enhanced in the buffer layer, the streamwise velocity fluctuation was suppressed while the wall-normal velocity fluctuation was strength- ened. Furthermore, it should be mentioned that rheological phenomenon occurs in the buffer layer, prob- ably related to the addition of large particles d~ = 4. In the respect of drag reduction, the smaller patti- ＋ ＋ cles dp 42 had almost the same performance, however, particles dp = 4 had barely the ability of drag re- duction. On the whole, for the cases studied, the fine-particles＇ drag-reducing capability was attenuated with the dimensionless particle size increasing.