多孔介质电渗泵的数值仿真与性能分析

电渗驱动微泵是一种新型的电动力式微泵,其输出压强高,流量可调范围宽,可用于微通道冷却系统中。建立了多孔介质电渗泵电渗流的数学模型,并对其性能进行了分析。根据双电层模型与电渗泵的控制方程,得出电渗流的近似解析模型,求出最大流率与压力。利用MEMS数值仿真软件CoventorWare对电渗泵模型进行求解分析,得到电渗泵流场和压力场的分布;对其特性进行分析,研究电场强度、溶液浓度和微流道孔径及其流道长度对电渗泵性能的影响。结果表明,在电渗驱动下,微流道中的流体流动速度与电场强度及微流道表面静电势成正比;流体速度与微通道长度成反比,与孔径无关。

Numerical Simulation and Performance Analysis of Porous Media Electroosmotic Pump

The electroosmotic micropump is a novel electro-dynamic pump which has the advantages of high pressure,a wide range of flow rate,and suitability for microchannel cooling system.The theoretical formulation and performance analysis of the porous media electroosmotic pump were introduced,and the mathematical models of electroosmotic flow were constructed.Electric double layer and governing equations of EO pump were presented.Approximate analytical model of EOF was obtained and maximum flow rate and pressure can be equated.Electroosmotic pump model was analyzed using CoventorWare,a MEMS numerical simulation software.Flow and pressure field distribution of electroosmotic pump was obtained.The influence of electric field,ionic concentration and pore size and length of microchannel on the performance of electroosmotic pump was analyzed.The results show that microflow rate is proportional to the electrical field strength and zeta potential,and microflow rate is inversely propotional to the length of microchannel,independent of pore size.The results provide the references for the design of electroosmotic pumps in microchannel cooling system.