探討焦耳熱對微流道電滲流的影響

Numerical investigation of Joule heat effect on the electroosmotic flow motion in microchannels

郭勝修(Sheng-Hsiu Kuo)

指導教授 ： 許文翰

國立臺灣大學/工學院/工程科學及海洋工程學研究所/碩士(2008年)

https://doi.org/10.6342/NTU.2008.00813

摘要

本論文是應用對流-擴散-反應數值算則求解微流體晶片中之穩態流場方程式，
其中包含外加電場之Laplace方程、描述壁面電位之Poisson-Boltzmann方程、
描述包含電驅動力不可壓縮流傳輸現象之Navier-Stokes方程及受焦耳熱影響之能量方程。

論文之內容可分成二維及三維兩個部分。
針對二維問題，研究主題是焦耳熱對電滲流行為的影響，
並描繪出靠近壁面之速度邊界層、電荷擴散層以及電雙層。
另外針對不同電導率、不同壁面電位(Zeta potential)及觀察溫度變化如何影響電滲流流場亦是研究的主題。
三維則設計一簡單的矩形渠道模擬電滲流在微流管道內的行為。

關鍵字

對流-擴散-反應 ； 電滲流 ； Possion-Boltzmann方程 ； 電雙層

並列摘要

In this study, a convection-diffusion-reaction scheme
is applied to solve the transient transport equations for the
prediction of steady electroosmotic microchannel flow behavior. The
governing equations for the total electric field include the Laplace
equation for the effective electrical potential and the
Poisson-Boltzmann equation for the electrical potential in the
electric double layer. The transport equations governing the
hydrodynamic field variables comprise the mass conservation equation
for the electrolyte and the equations of motion for the
incompressible charged fluid flow subject to an electroosmotic body
force.

In two dimensional model, one of the main aims of the current study is to elucidate the effect
of Joule heating, which can affect the electrohydrodynamic behavior.
Investigation into the region near the negatively charged channel
wall will be made through the simulated velocity boundary layer,
diffuse layer and the electric double layer.
The other is to elucidate the energy generation due to
Joule heating, which can affect the electrohydrodynamic behavior,
for the cases investigated at different ionic conductivities and wall zeta potentials.
This paper reports 3D numerical analysis of the Joule heating and its effects on the electrokinetic
transport of solutes in a simple rectangular microchannels.

並列關鍵字

convection-diffusion-reaction ； electroosmotic flow ； electric double layer

參考文獻

for miniaturization and integration of sepatation techniques into monitoring

[4] Grahame, D. C., The Electrical Double Layer and the Theory od Electrocapil-

larity, Chem. Rev. , Vol. 41, pp. 441-501, 1947

Academic Press, 1981

[7] Burgreen D. and Nakache F. R., Electrokinetic °ow in ultra‾ne capillary sites,