A Numerical Model to Simulate Diffuse Effects in Microfluidic Fuel Cells

2010 ◽  
Author(s):  
Isaac B. Sprague ◽  
Prashanta Dutta
Keyword(s):  
Fuel Cell ◽  
Numerical Model ◽  
Laminar Flow ◽  
Ion Transport ◽  
Double Layer ◽  
Electric Double Layer ◽  
Double Layers ◽  
Algebraic Equations ◽  
Microfluidic Fuel Cell ◽  
Volume Method

A 2D numerical model is developed for a laminar flow fuel cell considering ion transport and the electric double layer around the electrodes. The Frumkin-Butler-Volmer equation is used for the fuel cell kinetics. The finite volume method is used to form algebraic equations from governing partial differential equations. The numerical solution was obtained using Newton’s method and a block TDMA solver. The model accounts for the coupling of charged ion transport with the electric field and is able to fully resolve the diffuse regions of the electric double layer in both the stream-wise and cross-channel directions. Different operating phenomena, such as laminar flow separation and the development of the depletion boundary layers and electric double layers are obtained. These numerical results demonstrate the model’s ability to capture the complex behavior of a microfluidic fuel cell which has been ignored in previous 1D models.

Rectified Ion Transport in Ultra‐thin Membrane Governed by Outer Membrane Electric Double Layer

2020 ◽  
Vol 38 (12) ◽  
pp. 1757-1761
Author(s):  
Zhenkun Zhang ◽  
Chao Wang ◽  
Lingxin Lin ◽  
Mengyi Xu ◽  
Yichun Wu ◽  
...  
Keyword(s):  
Ion Transport ◽  
Outer Membrane ◽  
Double Layer ◽  
Electric Double Layer ◽  
Thin Membrane

Modeling of Electroosmotic Nanoflows With Overlapped Double Layer

2011 ◽  
Author(s):  
Reza Nosrati ◽  
Mehrdad Raisee ◽  
Ahmad Nourbakhsh
Keyword(s):  
Zeta Potential ◽  
Double Layer ◽  
Electric Double Layer ◽  
Potential Distribution ◽  
Present Model ◽  
Ionic Concentration ◽  
Channel Height ◽  
Parabolic Profile ◽  
Poisson Boltzmann ◽  
Volume Method

In the present paper a new model is proposed for electric double layer (EDL) overlapped in nanochannels. The model aimed to obtain a deeper insight of transport phenomena in nanoscale. Two-dimensional Nernst and ionic conservation equations are used to obtain electroosmotic potential distribution in flow field. In the proposed study, transport equations for flow, ionic concentration and electroosmotic potential are solved numerically via finite volume method. Moreover, Debye-Hu¨ckle (DH) approximation and symmetry condition, which limit the application, are avoided. Thus, the present model is suitable for prediction of electroosmotic flows through nanochannels as well as complicated asymmetric geometries with large nonuniform zeta potential distribution. For homogeneous zeta potential distribution, it has been shown that by reduction of channel height to values comparable with EDL thickness, Poisson-Boltzmann model produces inaccurate results and must be avoided. Furthermore, for overlapped electric double layer in nanochannels with heterogeneous zeta potential distribution it has been found that the present model returns modified ionic concentration and electroosmotic potential distribution compare to previous EDL overlapped models due to 2D solution of ionic concentration distribution. Finally, velocity profiles in EDL overlapped nanochannels are investigated and it has been showed that for pure electroosmotic flow the velocity profile deviates from the expected plug-like profile towards a parabolic profile.

scholarly journals A Double-Bridge Channel Shape of a Membraneless Microfluidic Fuel Cell

Energies ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6973
Author(s):  
Ji-Hyun Oh ◽  
Muhammad Tanveer ◽  
Kwang-Yong Kim
Keyword(s):  
Fuel Cell ◽  
Numerical Model ◽  
Power Density ◽  
Flow Channel ◽  
Channel Width ◽  
Channel Height ◽  
Cross Sectional ◽  
Channel Shape ◽  
Microfluidic Fuel Cell ◽  
Inner Channel

A double-bridge shape is proposed as a novel flow channel cross-sectional shape of a membraneless microfluidic fuel cell, and its electrochemical performance was analyzed with a numerical model. A membraneless microfluidic fuel cell (MMFC) is a micro/nano-scale fuel cell with better economic and commercial viability with the elimination of the polymer electrolyte membrane. The numerical model involves the Navier–Stokes, Butler–Volmer, and mass transport equations. The results from the numerical model were validated with the experimental results for a single-bridge channel. The proposed MMFC with double-bridge flow channel shape performed better in comparison to the single-bridge channel shape. A parametric study for the double-bridge channel was performed using three sub-channel widths with the fixed total channel width and the bridge height. The performance of the MMFC varied most significantly with the variation in the width of the inner channel among the sub-channel widths, and the power density increased with this channel width because of the reduced width of the mixing layer in the inner channel. The bridge height significantly affected the performance, and at a bridge height at 90% of the channel height, a higher peak power density of 171%was achieved compared to the reference channel.

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