固着液滴的流固耦合模态仿真分析

Fluid-Solid Coupling Modal Analysis of Sessile Droplets

为解决固着液滴仿真模态分析的建模与求解问题,开展了基于流固耦合作用下的固着液滴有限元建模仿真及对比分析。采用流固耦合分离建模方法,将流体的表面张力等效成类薄膜结构,建立了固着液滴的有限元仿真模型,给定已知的结构约束和耦合,模拟实际工况条件。同时对固有频率、特征振型和质心最大改变量的理论计算值和仿真值进行分析比较。结果表明:固着液滴2~5阶的仿真固有频率均大于根据Rayleigh理论计算得到的结果,与现有文献的理论证明结果相符;有限元仿真得到的固着液滴四阶振型谱图与现有文献得到的实验振型谱吻合;液滴质心振动最大位移仿真值与理论计算值的相对误差不超过25%。

A new finite element modeling method based on fluid-solid coupling was proposed to solve the modeling and solution problems of sessile droplet.Using the method of fluid-solid coupling separation modeling,the surface tension of the fluid was equivalent to a film structure.Then the finite element simulation model of the sessile droplet was built,simulating the actual working condition and giving the known structural constraint and coupling constraint.The theoretical value and simulation value of natural frequency,characteristic array and maximum change of mass center were analyzed and compared.The results show that the simulation frequency of the 2-5 order solid droplet is larger than the calculated results by Rayleigh s theory,which is in consistent with proved results in exis-ting literature.The 4 order vibration spectrum of the solid droplet obtained by the finite element simulation is consistent with the vibration spectrum of experiment in literature.The relative error between the maximum displacement of the center of mass obtained by the droplet simulation and the theoretical calculated value is less than 25%.