On the Influence of Nanoparticle Shapes for Nanofluids Flow Behaviors by Molecular Dynamics Simulation

Understanding how the nanoparticles influence flow behavior of nanofluids is important for revealing mechanism of heat transfer enhancement by using nanofluids. The aim of this work was to study the microscopic change in base fluid and micro-motion of nanoparticles due to Brownian motion by molecular dynamics simulation. The present work established shearing flow simulation models considering different shapes of nanoparticles. Velocity distribution and number density distribution of fluid, and angular velocity components and translational velocity components of nanoparticles were statistically analyzed. The results of velocity distribution and number density distribution showed that adding nanoparticles reduces flow boundary layer and causes uneven distribution of mass; and the results for angular velocity components and translational velocity components of nanoparticles showed that nanoparticles rotate fast in the fluid, and vibrate irregularly. The present study suggests that adding nanoparticles causes microscopic change for base fluid including reducing thickness of flow boundary layer and uneven density distribution in fluid. In addition, the micro-motions of nanoparticles including rotation and vibration due to Brownian motion strengthen micro-flow effect and momentum transfer in nanofluids. Furthermore, by comparing motion behaviors of nanoparticles in different shapes the present work reveals that shapes of nanoparticles influence deeply flow behavior of nanofluids.