On the Microscopic Flow Characteristics of Nanofluids by MolecularDynamics Simulation on Couette Flow

摘要

Adding a small amount of nanoparticles to conventional fluids (nanofluids) has been proved to be an effectiveway for improving capability of heat transferring in base fluids. The change in micro structure of base fluids and micromotion of nanoparticles may be key factors for heat transfer enhancement of nanofluids. Therefore, it is essential toexamine these mechanisms on microscopic level. The present work performed a Molecular Dynamics simulation onCouette flow of nanofluids and investigated the microscopic flow characteristics through visual observation and statisticanalysis. It was found that the even-distributed liquid argon atoms near solid surfaces of nanoparticles could be seemed asa reform to base liquid and had contributed to heat transfer enhancement. In the process of Couette flow, nanoparticlesmoved quickly in the shear direction accompanying with motions of rotation and vibration in the other two directions.When the shearing velocity was increased, the motions of nanoparticles were strengthened significantly. The motions ofnanoparticles could disturb the continuity of fluid and strengthen partial flowing around nanoparticles, and furtherenhanced heat transferring in nanofluids.