本文關鍵詞：基于PNP模型的平板微通道非牛頓冪律流體電滲流的數(shù)值模擬研究　出處：《南昌大學》2015年碩士論文　論文類型：學位論文

  更多相關文章： 微通道 電滲流 Poisson-Nernst-Planck模型 數(shù)值模擬 粗糙壁面

【摘要】：微流控芯片可以完成液體樣品的分離、混合、反應、檢測等操作過程,這些過程大部分是需要在微通道中進行的,血液、蛋白質溶液等非牛頓冪律流體常作為生物流體分析的樣品進入微通道中,因而對微通道內非牛頓冪律流體的研究具有重大意義。本文基于Poisson-Nernst-Planck(PNP)模型,采用有限元法(FEM)數(shù)值模擬了非牛頓冪律流體在微通道內的電滲流(EOF)。主要的研究內容和成果如下:1、基于雙電層(EDL)機理,分析了PNP模型平板微通道非牛頓冪律流體EOF的數(shù)學模型,并建立FEM離散模型。將PNP模型數(shù)值解和諸多假設條件下成立的線性Poisson-Boltzmann模型精確解對比,驗證了PNP模型冪律流體EOF的正確性和普適性。2、對薄雙電層PNP模型平板微通道非牛頓冪律流體EOF進行了量綱分析和FEM模擬,得出了不同參數(shù)對EDL電勢和EOF速度的影響規(guī)律。研究表明,ζ電勢影響EDL電勢的大小,正負離子化合價會影響EDL的厚度。稠度系數(shù)、外加電場、ζ電勢等僅改變EOF速度的大小;冪律指數(shù)、正負離子化合價不僅改變速度的大小,而且會影響壁面附近流體速度從零發(fā)展到最大值時相對壁面的距離。EOF速度和外加電場、稠度系數(shù)、ζ電勢等呈冪函數(shù)關系,其中稠度系數(shù)的指數(shù)為冪律指數(shù)的負倒數(shù)。微通道高度、離子擴散系數(shù)對EOF沒有影響。這些結果對微通道冪律流體EOF機理的認知和操控技術的改進有指導作用。3、基于PNP模型,數(shù)值模擬了冪律流體在矩形、三角形、正弦、分形粗糙元壁面微通道的EOF,討論相對粗糙度、粗糙元頻率等特征對壁面附近EDL電勢、流速和微通道流體流量的影響,揭示了粗糙元對EOF的影響規(guī)律。這些結果對微流控芯片電滲驅動的理論發(fā)展和實際應用具有參考價值。
[Abstract]:Separation, microfluidic chip can complete liquid sample mixing, reaction, detection process, most of these processes are needed in micro channel, blood, protein solution and other non Newton power-law fluid is often used as a biological fluid sample into the micro channel, so the study of micro channel non Newton power-law fluid is of great significance. This paper is based on Poisson-Nernst-Planck (PNP) model, using the finite element method (FEM) numerical simulation of electroosmotic flow of power-law fluid in non Newton in the micro channel (EOF). The main research contents and results are as follows: 1, based on the electric double layer (EDL) mechanism, analyzes the mathematical model of PNP micro channel non Newton power-law fluid EOF, and the establishment of FEM model. Compared with exact solutions of the linear Poisson-Boltzmann model established PNP model numerical solution and many assumptions, validated PNP model of power-law fluid EOF The correctness and universality of.2, thin double layer PNP model of micro channel plate non Newtonian power-law fluid of EOF dimensional analysis and FEM simulation, the effects of different parameters on the EDL potential and the EOF speed. The research results show that the zeta potential of the EDL potential size of positive and negative ions will affect the price of EDL the thickness of the consistency coefficient, the applied electric field, the zeta potential only change the speed of the EOF size; power-law index, positive and negative ion valence not only change the magnitude of the velocity, but also affect the near wall fluid velocity from zero to the maximum value when the relative wall distance and speed of.EOF electric field, the consistency coefficient, a power the function relationship between the zeta potential, the viscosity index of the power-law index of the negative reciprocal. Micro channel height, ion diffusion coefficient has no effect on EOF. These results have guidance to improve the micro channel power law fluid EOF mechanism and cognitive control technology The role of.3, based on the PNP model, the numerical simulation of a power-law fluid in a rectangular, triangular, sinusoidal, fractal roughness wall micro channel EOF, discussed the relative roughness, roughness frequency characteristics of near surface EDL potentials, the micro channel flow velocity and fluid flow effects, the influences of roughness element on EOF. These results have reference value to the theoretical development of microfluidic electroosmotic and practical application.

【學位授予單位】：南昌大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：TN492

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本文編號：1404403