From measurements of hydrodynamics to computation of species transport in falling films
From measurements of hydrodynamics to computation of species transport in falling films
复制标题
DOI：
10.1016/j.ijrefrig.2009.02.008
复制
发表时间：
2009-06
期刊：
影响因子：
--
通讯作者：
V. Subramaniam;S. Garimella
中科院分区：
文献类型：
--
作者：
V. Subramaniam;S. Garimella
水平管束降膜在吸收式热泵中有着广泛的应用。文献中的液膜传热和传质模型是基于对这种流动的简单假设。在管下形成的液滴落在随后的管上，并且随后在液膜上的波纹和混合影响吸收。高速流动可视化，图像分析和计算用于了解流体动力学对局部吸收现象的影响。图像分析在数学上描述了界面，以及液滴的表面积和体积。这些流量也进行了数值分析，使用的液体-蒸汽界面的流体体积法。三维模型以高保真度证实了实验中观察到的液滴形成、分离和撞击。完全解决的耦合流体流动和传热传质的3-D计算揭示了当地的梯度和传输速率，以及它们在降膜和管间区域的空间和时间变化。
Falling films on horizontal tube banks are widely used in absorption heat pumps. Liquid film heat and mass transfer models in the literature are based on simplistic assumptions about such flows. Droplets forming under the tubes fall on subsequent tubes, and the ensuing waviness and mixing on the liquid film affect absorption. High-speed flow visualization, image analysis, and computations are used to understand the effect of hydrodynamics on local absorption phenomena. Image analysis mathematically describes the interface, and the surface area and volume of the droplets. These flows are also numerically analyzed using the volume-of-fluid method for the liquid–vapor interface. The 3-D model corroborates with high fidelity the droplet formation, detachment and impact observed in experiments. Fully resolved 3-D computations of the coupled fluid flow and heat and mass transfer reveal the local gradients and transfer rates, and their spatial and temporal variations in the falling-film and inter-tube regions.