Investigation of the Shape of the Anode Flow Channel in a Direct Ethanol Polymer Electrolyte Fuel Cell -Optimization of the Sharp Turn Corner Shape by Numerical Flow Analysis with a Genetic Algorithm-

Abstract

Polymer electrolyte fuel cells, which have been developed for mobile equipment, are mainly direct methanol fuel cells (DMFC). From the standpoint of safety to a human body, it is desirable to use ethanol as fuel. In order to improve the performance of direct ethanol fuel cells (DEFC), it is necessary to investigate the fuel flow pattern in the anode flow channel with many sharp turn corners in the fuel cell, and to improve the channel shape. So, in this study, the velocity distribution of the water flow in a micro-channel was numerically analyzed using the authors' GTT code and the calculated results were verified by the velocity measurement with a line LDV system. For reducing the pressure loss in consideration of the suppression of flow stagnation in the channel, it was attempted to optimize the sharp turn corner shape by three-dimensional numerical flow analysis with a genetic algorithm (GA) and a shape with less pressure loss was found.

Numerical Simulation of Concentration Over-voltage in a Polymer Electrolyte Fuel Cell under Low-Hydrogen Conditions

“…The water temperature was 298 K, its kinematic viscosity was 1.004 × 10 −6 m 2 /s, and the average inlet velocity was 0.04 m/s. Figure 3 shows calculation results of the x-direction velocity, and the results of a laser Doppler velocimetry experiment performed by Taninaka et al are also shown for comparison [23]. The calculation results of the CFD model show good agreement with the experimental data.…”

“…Figure 6 shows the relationship between cell voltage and current density under two hydrogen concentration conditions, 10 and 30 vol.%. When the hydrogen concentration is 10 vol.%, the cell voltage rapidly decreases with increasing current density, unlike x-direction velocity comparisons between CFD result and LDV measurement data by Taninaka.et al [23].…”

Noninvasive In-vivo Measurements of Microvessels by Reflection-Type Micro Multipoint Laser Doppler Velocimeter

“…Taninaka et al have numerically analyzed the flow dynamics in a serpentine flow channel. 9,10) They found that the velocity distribution in a straight region is parabolic and that the flow obeys the Navier-Stokes equations for a Newtonian fluid, whereas the flow splits into two flows in corners since there is flow overrun. This phenomenon was observed in the experimental results obtained [see the region indicated by dashed ellipses in Fig.…”

Multi-channel laser Doppler velocimetry using a two-dimensional optical fiber array for obtaining instantaneous velocity distribution characteristics

“…[14][15][16][17][18] However, in recent years, more advanced methods are required in order to investigate topics such as unsteady three-dimensional turbulent flow, micro-scale flow in electronics devices, and flow in biochemical systems. [19][20][21][22][23][24][25][26] We have previously developed a laser Doppler velocimeter (LDV) that is capable of measuring the velocity at multiple points along a straight line, and is based on a conventional single-point LDV. 22,23,25) This instrument is referred to as a liner multipoint LDV (L-MLDV).…”