液滴撞击弹性悬臂梁行为的全拉格朗日数值方法  

Fully Lagrangian Numerical Method for the Behavior of Droplet Impact on Elastic Cantilever Beams

作　　者：蒋璇 孙中国[1] 孙一颉 刘启新 席光[1] JIANG Xuan;SUN Zhongguo;SUN Yijie;LIU Qixin;XI Guang(School of Energy and Power Engineering,Xi’an Jiaotong University,Xi’an 710049,China)

机构地区：[1]西安交通大学能源与动力工程学院,西安710049

出　　处：《西安交通大学学报》2024年第12期99-110,共12页Journal of Xi'an Jiaotong University

基　　金：国家自然科学基金资助项目(51922085)。

摘　　要：针对以往研究容易忽略弹性壁面变形对液滴撞击壁面的影响,以及传统网格方法在模拟自由表面大变形、弹性体耦合上易出现网格畸变等问题,提出了耦合移动粒子半隐式法(MPS)与离散单元法(DEM)的全拉格朗日液滴-弹性体相互作用数值方法。基于该方法,模拟了跳板效应、液滴反弹和铺展、板变形和振动等非线性现象,并通过与实验或理论解的对比,验证了方法的准确性。进一步探究了液滴撞击悬臂薄板的动态过程,分析了撞击速度和角度对液滴与薄板相互作用的影响。数值结果表明:悬臂梁末端最大偏移量随法向撞击速度呈线性增加,当液滴撞击角度θ≥90°时,接触时间随撞击角度的增加呈现先减小后增大然后再减小的趋势,当撞击角度θ<90°时,接触时间随撞击角度的增加呈现先增大后减小的趋势;液滴重心投影点的位置是影响液滴铺展系数与悬臂梁最大偏移量的主要因素,法向韦伯数相同的情况下,θ≥90°时的液滴铺展系数始终大于θ<90°的,而θ<90°时的悬臂梁最大偏移量始终大于θ≥90°的。该研究加深了对液滴撞击动力学的理解,可为涂层工艺和液滴传感技术等提供参考。Given that the influence of elastic substrate deformation on the impact of droplets on the substrate has tended to be overlooked in previous studies and the traditional mesh method is susceptible to mesh distortion in simulating large deformations of free surfaces and the coupling of elastic bodies,a fully Lagrangian numerical method for droplet-elastic body interaction is proposed,combining the moving particle semi-implicit(MPS)method with the discrete element method(DEM).Through this method,nonlinear phenomena such as the springboard effect,droplet rebound and spreading,plate deformation,and vibration are simulated.The accuracy of the method is validated through comparisons with experimental or theoretical results.Additionally,an in-depth analysis of the dynamic process of droplet impact on a cantilevered thin plate is conducted,focusing on the influence of impact velocity and angle on the interaction between the droplet and the thin plate.Numerical results indicate that the maximum deflection at the end of the cantilever beam linearly increases with the normal impact velocity.When the droplet impact angleθis greater than 90°,the contact time initially decreases,then increases,and eventually decreases as the impact angle increases.Conversely,when the impact angleθis less than 90 degrees,the contact time initially increases and then decreases as the impact angle increases.The spreading coefficient of the droplet and the maximum deflection of the cantilever beam are predominantly influenced by the position of the droplet’s center of mass projection.Under the same normal Weber number conditions,the droplet spreading coefficient is always greater forθ≥90°than forθ<90°,and the maximum deflection of the cantilever beam is always greater forθ<90°than forθ≥90°.This study enhances the understanding of droplet impact dynamics and can provide insights for coating processes,droplet sensing technology,and other related fields.

关 键 词：移动粒子半隐式法 离散单元法 液滴 弹性体 

分 类 号：O353.4[理学—流体力学]