A Nonconforming Spectral Element Method for Electroosmotically Induced Microfluidic Mixing

电渗诱导微流体混合的非一致谱元方法

• 批准号: 0306622
• 负责人: Ali Beskok
• 金额: $ 15.78万
• 依托单位: Texas A&M Engineering Experiment Station
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-09-01 至 2007-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0306622&HistoricalAwards=false
• 关键词: Nonconforming; Spectral; Element; Method; Electroosmotically

In this project, we will develop a comprehensive theoretical and numerical research program to investigate the micro-scale species mixing. We will particularly study mixing induced by time-periodic electroosmosis that is driven by externally applied electric fields, hence eliminating the need for mechanical pumping components. Rapid switching between several electric field configurations will be utilized to create different flow fields, resulting in increased interspecies contact area and/or chaotic mixing. Numerical simulations of mixing require robust algorithms that minimize the dispersion and diffusion errors. To address this need, we will develop nonconforming spectral element algorithms using the Mortar element and constrained approximation methods. Our approach will allow both h-type and p-type nonconformities for efficient resolution of all flow features, including the thin electric double layers. In addition to the three-dimensional Navier-Stokes and species transport equation solvers, we will develop necessary algorithms to calculate the particle trajectories, Poincare sections, and other tools required to characterize the chaotic mixing and mixing efficiency. Implementation of both the Mortar element and constrained approximation methods will also allow detailed comparisons between the accuracy and computational efficiency of these two schemes.In the absence of turbulence, mixing of fluids on micro-scales requires very long mixing lengths and long times. This creates significant challenges in design of efficient mixers for micro-fluidic devices, such as micro-total-analysis-systems, utilized in detection of biological and chemical agents for medical, pharmaceutical, and national security applications. Utilization of time-periodic electroosmosis allows design of new mixing strategies that either enhance diffusive mixing by increasing the interspecies contact area, or induce chaotic mixing. This project will enable enhanced understanding and characterization of electroosmotically induced chaotic and diffusive mixing. The research will facilitate development of new micro-fluidic mixing concepts, which can be implemented in design of new efficient micro-mixers for micro- and nano-fluidic applications.

在这个项目中，我们将开发一个全面的理论和数值研究计划来研究微尺度物质混合。 我们将特别研究由外部施加的电场驱动的时间周期电渗引起的混合，从而消除对机械泵部件的需要。 将利用几种电场配置之间的快速切换来创建不同的流场，从而增加种间接触面积和/或混沌混合。 混合的数值模拟需要强大的算法来最大限度地减少色散和扩散误差。 为了满足这一需求，我们将使用 Mortar 元素和约束近似方法开发非一致性谱元素算法。 我们的方法将允许 h 型和 p 型不合格品有效解决所有流动特征，包括薄双电层。除了三维纳维-斯托克斯和物质输运方程求解器之外，我们还将开发必要的算法来计算粒子轨迹、庞加莱截面以及表征混沌混合和混合效率所需的其他工具。砂浆单元和约束近似方法的实现也将允许对这两种方案的精度和计算效率进行详细比较。在没有湍流的情况下，微尺度上的流体混合需要非常长的混合长度和很长的时间。 这给微流体装置（例如用于检测医疗、制药和国家安全应用的生物和化学制剂的微全分析系统）的高效混合器的设计带来了重大挑战。 利用时间周期电渗可以设计新的混合策略，通过增加种间接触面积来增强扩散混合，或者诱导混沌混合。 该项目将增强对电渗引起的混沌和扩散混合的理解和表征。 该研究将促进新的微流体混合概念的开发，这些概念可以在用于微和纳米流体应用的新型高效微混合器的设计中实现。