环形和圆形微流道内的电渗流解析及其流体力学特性研究

发布时间：2018-02-04 22:11

本文关键词： 环管圆管电渗流 Debye-Hückel近似同伦法 Poisson-Boltzmann方程　出处：《广西大学》2017年硕士论文　论文类型：学位论文

【摘要】：本论文主要是通过寻找解析解并结合一定的数值模拟来探讨微流体在电渗(Electro-osmosis,简称EO)效应下的流动行为,并探讨在环形和圆形微流道内流体的各项物理性质,所使用的物理模型包括Poisson-Boltzmann equation(P-B方程)、Navier-Stokes equation(N-S 方程)和 Debye-Huckel Approximation(D-H 近似)等方程组。本论文将基于P-B方程和D-H近似来探讨环形和圆形微流道中的定常态电渗流动和非定常起始流动。本文首先基于线性D-H近似求解得到EO流动的解析解,然后通过同伦法(Method of Homotopy)将结果推广至非线性P-B方程。环管内外壁面可能会有不同的Zeta电势(分别标记为α,β),本文将研究内外壁面电势(α,β)、内外半径比6、动电宽度K以及P-B方程非线性衡量指标λ等因素对环管EO流动的影响。对任意给出的内外壁面电势(α,β),本文为得到定常态EO最大流量而对内外半径比b进行了最优化,并给出了其所对应的EO起始流动随时间变化的详细研究。本文还给出了不同K值时,最优化EO流量QM(α,β)与所对应的6(标记为bmax)在α-β平面上的变化趋势,这可作为实际应用做出有用的指导。本文还研究了不同λ值时,bmax和QM(a,β)的变化。本文分别研究了 Zeta电位在圆管壁面径向均匀分布和不均匀分布时的EO流动,并讨论了不同的K、λ值对定常态和非定常态EO流动的影响。对Zeta电势均匀分布的情形,本文给出了不同的K、λ值时EO流量随时间的变化,并给出了其所对应的EO起始流动在管道中的随时间变化的速度分布。本文通过一个Zeta电势在管道内存在一个周期性细微扰动的例子,研究了 Zeta电势不均匀分布时不同K、λ值的EO流动定常态速度在管道中的分布,及其所对应的非定常态起始流动速度和流量随时间的变化。
[Abstract]:In this paper, the flow behavior of micro-fluid under electroosmotic electroosmosisis (EO) effect is studied by searching for analytical solution and combining with certain numerical simulation. The physical properties of the fluid in circular and circular microchannels are discussed. The physical models used include the Poisson-Boltzmann equation(P-B equation. Navier-Stokes equation(N-S equation and Debye-Huckel Approximation(D-H approximation. In this paper, the stationary electroosmotic flow and unsteady initial flow in annular and circular microchannels are discussed based on P-B equation and D-H approximation. In this paper, EO is obtained based on linear D-H approximation. The analytical solution of the flow. Then the method of homotopy method is used to generalize the results to the nonlinear P-B equation. There may be different Zeta potentials (marked 伪) on the inner and outer walls of the ring tube. In this paper, the internal and external wall potential (伪, 尾) is studied, and the ratio of inner and outer radius is 6. The influence of the dynamic width K and the nonlinear measure index 位 of P-B equation on the EO flow in the annular tube, and on the internal and external wall potential (伪, 尾) given arbitrarily. In this paper, the internal and external radius ratio b is optimized to obtain the maximum flow rate of fixed normal EO, and the corresponding initial flow of EO is studied in detail with time. The different K values are also given in this paper. The change trend of optimized EO flow QM (伪, 尾) and corresponding 6 (marked bmax) on 伪-尾 plane can be used as useful guidance for practical application. Different 位 values are also studied in this paper. The change of bmax and QMMA, 尾. In this paper, the EO flow of Zeta potential on the wall of circular tube is studied, and the different K is discussed. The influence of 位 value on the steady and unsteady EO flow. For the case of uniform distribution of Zeta potential, the variation of EO flux with time at different K, 位 values is given in this paper. The time-varying velocity distribution of the corresponding initial EO flow in the pipeline is given. An example of the existence of a periodic slight disturbance in the pipe with Zeta potential is given. The distribution of constant normal velocity of EO flow with different K and 位 values in the pipeline and the variation of the initial flow velocity and flow rate of unsteady state with time are studied when the Zeta potential is not uniform.
【学位授予单位】：广西大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X53;TQ028.74

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