高校化学工程学报2025，Vol.39Issue(6)：972-982,11.DOI:10.3969/j.issn.1003-9015.2025.00.028
椭圆水平管降膜流型演化与三维液膜分布特性
Flow pattern evolution and three-dimensional liquid film distribution characteristics in falling film over elliptical horizontal tubes
摘要
Abstract
To address the unclear regulation mechanisms of liquid film distribution in industrial falling film heat ex-changers,this paper proposes a novel method that synergistically regulates the three-dimensional hydrodynamics of liquid films through superhydrophilic surface and elliptical tube installment.A combined visualization-spectroscopy experimental platform was constructed,integrating a confocal displacement spectrometer(1 000 Hz/1 μm preci-sion)and high-speed imaging for coordinated observation.The temporal and spatial evolution of liquid films during the transition from droplet flow to columnar flow was quantitatively analyzed with Re=59-220.The study reveals that a superhydrophilic surface fabricated via boehmite nanostructure modification(contact angle＜5°)results in an 11％reduction with liquid film thickness compared to hydrophilic tubes.When the major axis of the elliptical tube is oriented vertically,the circumferential uniformity of the liquid film improves,and axial central effect is en-hanced,such as that the liquid film thickness at l*=0.5 increases by 35％-41％compared to l*=0.A predic-tive formula relating film thickness to Reynolds number was established,and the pattern of deviation from the classi-cal Nusselt theory at Re(Re=88-118)was revealed.These findings provide theoretical support for the optimized design of industrial falling film heat exchangers.关键词
椭圆管/超亲水/滴状流/液膜厚度/降膜换热器Key words
elliptical tubes/superhydrophilic/droplet flow/liquid film thickness/falling film heat ex-changers分类
化学化工引用本文复制引用
刘旭,张帅帅,张楠,马学虎..椭圆水平管降膜流型演化与三维液膜分布特性[J].高校化学工程学报,2025,39(6):972-982,11.基金项目
国家自然科学基金(22478050). （22478050）
