ABSTRACT

The impact of presence of nano-scale particles inside a flow between two flat plates which known as Poiseuille flow is numerically analyzed. Nanofluids have been investigated in the past few years mainly by considering the heat transfer aspect in a fully developed section of internal flows, rather than detailing the hydrodynamic and thermal developing viewpoint of nanofluid. In other words, this research will focus on the fundamental understanding of developing nanoparticles flows in hydrodynamic and thermal boundary layers in the entrance region. Therefore, flow between two flat plates is numerically studied here by injecting and tracking nanoparticles from inlet to outlet of the channel. The flow is kept in the laminar regime with uniform heat flux applied on the plates. ANSYS Fluent 19.3 is used to numerically solve the continuity and momentum equations, as well as discrete phase modeling for particles. The results showed three major stages in vorticity development in the entrance region. It was found that Brownian motion plays an important role in nanoparticles migration, and close to the wall with the involvement of Thermophoresis. Also, nanoparticles can deviate from flow layers after merging boundary layers.

摘要

数值分析了存在于两个平板之间的流动（称为Poiseuille流动）中纳米级颗粒的存在的影响。在过去的几年中，主要通过在内部流动的充分发展的部分中考虑传热方面来研究纳米流体，而不是详细描述纳米流体的流体动力学和热发展观点。换句话说，本研究将集中于对进入区域内流体动力和热边界层中发展的纳米粒子流的基本理解。因此，此处通过从通道的入口到出口注入和跟踪纳米粒子来对两个平板之间的流动进行数值研究。气流保持层流状态，并在板上施加均匀的热通量。ANSYS Fluent 19。3用于数值求解连续性和动量方程，以及粒子的离散相建模。结果表明，入口区涡度发展的三个主要阶段。发现布朗运动在纳米颗粒迁移中起重要作用，并且在热泳作用下靠近壁。而且，纳米粒子在合并边界层后可能会偏离流动层。