Abstract The investigations on heat and mass transfer in the form of falling film flow were mainly focused on the simulation of heat and mass coupling adopting the continuity hypothesis of Navier-Stokes equations. Most of the previous works were done with laminar flow assumptions, or just deal with a very short smooth laminar section beyond the falling film entrance. In this paper, a study investigating the effects of wavy flow on stream absorption by falling liquid film is presented in the perspective of sorption refrigeration process. A multi-phase model lattice Boltzmann method is adopted to simulate the wavy falling liquid film flow, and the absorption process takes place in this flow field region. Absorption simulation was carried out using the laminar flow assumption with the semi-parabolic velocity distribution and the fluctuation results in the LBM simulation. When the overall simulation section is 1 m in length, with initial velocity 0.1 m/s for lithium bromide solution falling film flow, results show that the wave flow has apparent enhancement on heat and mass transfer. Local dimensionless numbers for mass (Sh) and heat (Nu) transfer with waves increase 4 times and 2 times, respectively, compared with the laminar flow.

中文翻译：

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基于格子Boltzmann方法的降膜吸收在中等雷诺数下的模拟

摘要 降膜流形式的传热传质研究主要集中在采用Navier-Stokes方程连续性假设的传热传质模拟。以前的大部分工作都是基于层流假设完成的，或者只是处理降膜入口之外的非常短的平滑层流部分。在本文中，从吸附制冷过程的角度研究了波状流动对降液膜吸收流的影响。采用多相模型格子Boltzmann方法来模拟波浪状下降液膜流动，吸收过程发生在该流场区域。吸收模拟是使用层流假设与半抛物线速度分布和 LBM 模拟中的波动结果进行的。当整体模拟截面长度为1 m，初始速度为0.1 m/s 的溴化锂溶液降膜流时，结果表明波流对传热传质有明显增强。与层流相比，随波传递的质量 (Sh) 和热量 (Nu) 传递的局部无量纲数分别增加了 4 倍和 2 倍。