螺旋微流道中液滴离心驱动

Centrifugal Driving of Column Flow in Spiral Microchannel

为研究离心驱动下液滴在螺旋微流道中的流动特性,建立了液滴流动物理模型;提出表面耗散的表达式并结合离心实验对其进行修正;利用仿真软件COMSOL计算黏性耗散公式中的系数;根据驱动功与耗散能守恒进而得到流速的理论公式;展开多因素多水平实验测量液滴的实际流速。结果表明:实际流速略小于理论预测值,但各因素对实际流速的影响与预测公式相符;液滴流动的特征表现为,毛细数和离心-邦德数呈正相关的线性关系,且较高的离心-邦德数对应的线性度更强。为其他方式驱动的液滴研究和相关应用的开发提供了理论借鉴和依据。

In order to study the flow characteristics of column in spiral microchannel under centrifugal field,column flow model is established.Firstly,the expression of surface dissipation is put forward by formula analysis and modified with centrifugal experiment,and the coefficient of viscous dissipation formula is calculated by COMSOL.Then,the theoretical formula of flow velocity is obtained according to the conservation of centrifugal-driving power and the sum of surface and viscous dissipated energy.Finally,the actual rate of column is measured by multi-factor and multi-level experiments.The results show that the actual flow rate is slightly lower than the theoretical prediction,but the influence of each factor on the actual flow rate is consistent with the prediction formula.Moreover,there is a positive linear relationship between Capillary number and Centrifugal-Bond number,but a higher Centrifugal-Bond number corresponds to a stronger linearity.The law of column provides a theoretical reference and basis for development of related applications and model analysis of other methods driving.