Wang Ruiqi, Duan Riqiang, Jia Haijun
Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100085, China.
Polymers (Basel). 2021 Apr 8;13(8):1205. doi: 10.3390/polym13081205.
This publication focuses on the experimental validation of film models by comparing constructed and experimental velocity fields based on model and elementary experimental data. The film experiment covers Kapitza numbers Ka = 278.8 and Ka = 4538.6, a Reynolds number range of 1.6-52, and disturbance frequencies of 0, 2, 5, and 7 Hz. Compared to previous publications, the applied methodology has boundary identification procedures that are more refined and provide additional adaptive particle image velocimetry (PIV) method access to synthetic particle images. The experimental method was validated with a comparison with experimental particle image velocimetry and planar laser induced fluorescence (PIV/PLIF) results, Nusselt's theoretical prediction, and experimental particle tracking velocimetry (PTV) results of flat steady cases, and a good continuity equation reproduction of transient cases proves the method's fidelity. The velocity fields are reconstructed based on different film flow model velocity profile assumptions such as experimental film thickness, flow rates, and their derivatives, providing a validation method of film model by comparison between reconstructed velocity experimental data and experimental velocity data. The comparison results show that the first-order weighted residual model (WRM) and regularized model (RM) are very similar, although they may fail to predict the velocity field in rapidly changing zones such as the front of the main hump and the first capillary wave troughs.
本出版物重点通过基于模型和基础实验数据比较构建的速度场和实验速度场，对薄膜模型进行实验验证。薄膜实验涵盖了卡皮察数(Ka = 278.8)和(Ka = 4538.6)、雷诺数范围为(1.6 - 52)以及扰动频率为(0)、(2)、(5)和(7)Hz。与先前的出版物相比，所应用的方法具有更精细的边界识别程序，并提供了额外的自适应粒子图像测速（PIV）方法来处理合成粒子图像。通过与实验粒子图像测速和平面激光诱导荧光（PIV/PLIF）结果、努塞尔特的理论预测以及稳态平板情况下的实验粒子跟踪测速（PTV）结果进行比较，验证了该实验方法，并且瞬态情况下良好的连续性方程再现证明了该方法的准确性。基于不同的薄膜流动模型速度剖面假设（如实验薄膜厚度、流速及其导数）重建速度场，通过比较重建速度实验数据和实验速度数据，提供了一种薄膜模型的验证方法。比较结果表明，一阶加权残差模型（WRM）和正则化模型（RM）非常相似，尽管它们可能无法预测快速变化区域（如主峰前部和第一个毛细波波谷）的速度场。
