An experimental study on the oscillation dynamics of wind-driven droplets at the verge of shedding

IF 3.3 2区工程技术 Q2 ENGINEERING, MECHANICAL

Experimental Thermal and Fluid Science Pub Date : 2025-08-12 DOI:10.1016/j.expthermflusci.2025.111593

Zichen Zhang , Xueqin Bu , Guiping Lin , Liang Wang , Jiayi Bao

{"title":"An experimental study on the oscillation dynamics of wind-driven droplets at the verge of shedding","authors":"Zichen Zhang , Xueqin Bu , Guiping Lin , Liang Wang , Jiayi Bao","doi":"10.1016/j.expthermflusci.2025.111593","DOIUrl":null,"url":null,"abstract":"<div><div>An experimental investigation was conducted to explore the dynamics of droplet oscillation for wind-driven droplets. Droplet profiles and velocity fields in the symmetry plane of the droplets were measured using time-resolved particle image velocimetry (PIV) and high-speed imaging techniques. These measurements enabled analysis of the droplet oscillation dynamics. The eigenfrequencies of the droplet oscillation, velocity fluctuations in droplet wake, and the natural oscillation were measured. It was found that droplet oscillation is a self-excited oscillation rather than a vortex-induced oscillation. Due to the self-excited oscillation, the eigenfrequency of wind-driven droplets coincides with the eigenfrequency of the natural oscillation. Furthermore, the self-excited oscillation leads to periodic velocity fluctuations in the shear layer, resulting in a frequency that closely matches that of the droplet oscillation. Velocity fluctuations diminish with the cessation of droplet oscillation for high-viscosity droplets. Based on the oscillation characteristics, a dynamic model of droplet oscillation was developed to address the research gap. The oscillation characteristics of the droplet centroid predicted by the developed model are consistent with the experimental results.</div></div>","PeriodicalId":12294,"journal":{"name":"Experimental Thermal and Fluid Science","volume":"170 ","pages":"Article 111593"},"PeriodicalIF":3.3000,"publicationDate":"2025-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Experimental Thermal and Fluid Science","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0894177725001876","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENGINEERING, MECHANICAL","Score":null,"Total":0}

引用次数: 0

Abstract

An experimental investigation was conducted to explore the dynamics of droplet oscillation for wind-driven droplets. Droplet profiles and velocity fields in the symmetry plane of the droplets were measured using time-resolved particle image velocimetry (PIV) and high-speed imaging techniques. These measurements enabled analysis of the droplet oscillation dynamics. The eigenfrequencies of the droplet oscillation, velocity fluctuations in droplet wake, and the natural oscillation were measured. It was found that droplet oscillation is a self-excited oscillation rather than a vortex-induced oscillation. Due to the self-excited oscillation, the eigenfrequency of wind-driven droplets coincides with the eigenfrequency of the natural oscillation. Furthermore, the self-excited oscillation leads to periodic velocity fluctuations in the shear layer, resulting in a frequency that closely matches that of the droplet oscillation. Velocity fluctuations diminish with the cessation of droplet oscillation for high-viscosity droplets. Based on the oscillation characteristics, a dynamic model of droplet oscillation was developed to address the research gap. The oscillation characteristics of the droplet centroid predicted by the developed model are consistent with the experimental results.

查看原文本刊更多论文

风致液滴脱落边缘振荡动力学的实验研究

对风驱动液滴的振荡动力学进行了实验研究。采用时间分辨粒子图像测速（PIV）和高速成像技术测量了液滴对称面上的液滴轮廓和速度场。这些测量使液滴振荡动力学分析成为可能。测量了液滴振荡的特征频率、液滴尾迹的速度波动以及液滴的自然振荡。结果表明，液滴振荡是一种自激振荡，而不是涡激振荡。由于自激振荡，风滴的本征频率与自然振荡的本征频率重合。此外，自激振荡导致剪切层的周期性速度波动，导致其频率与液滴振荡的频率密切匹配。对于高粘度液滴，速度波动随着液滴振荡的停止而减小。基于液滴振荡特性，建立了液滴振荡动力学模型，弥补了研究空白。该模型预测的液滴质心振荡特性与实验结果吻合较好。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Experimental Thermal and Fluid Science 工程技术-工程：机械

CiteScore

6.70

自引率

3.10%

发文量

159

审稿时长

34 days

期刊介绍： Experimental Thermal and Fluid Science provides a forum for research emphasizing experimental work that enhances fundamental understanding of heat transfer, thermodynamics, and fluid mechanics. In addition to the principal areas of research, the journal covers research results in related fields, including combined heat and mass transfer, flows with phase transition, micro- and nano-scale systems, multiphase flow, combustion, radiative transfer, porous media, cryogenics, turbulence, and novel experimental techniques.