为研究颗粒和近壁湍流的相互作用和流动阻力问题，采用点力双向耦合模型并结合Lagrange 粒子追踪法，对负载颗粒的槽道湍流进行直接数值模拟(direct numerical simulation, DNS).同时，从含颗粒作用外力项的NavierStokes方程出发，推导颗粒加载湍流的阻力系数表达式.考察较低容积比下粒径小于Kolomogrov尺度的颗粒对湍流结构的调制以及湍流减阻现象，讨论颗粒尺度和数量等加载参数对阻力系数的影响，发现在本研究范围内的细微颗粒对湍流的调制以抑制作用为主，同时产生明显的减阻效应.

This paper reports turbulence modulations and the accompanying drag reduction observed in direct numerical simulation (DNS) of particleladen channel flow. The pointforce twoway coupling model is applied to describe the interaction between the particle and the turbulence. Lagrangian tracking approach is used to describe the dynamics of particles, and derive a formula of drag coefficient from NavierStokes equations. Flow visualizations show that turbulence production can be suppressed by particles. Comparing the results of particleladen and unladen flows, the impact of the diameter and number of the particles on friction reduction are examined.