Numerical investigation on the sensitivity of endplate design and gas diffusion material models in quantifying localized interface and bulk electrical resistance

2021 ◽  
Vol 46 (33) ◽  
pp. 17358-17373
Author(s):  
Umesh Shinde ◽  
Poornesh K. Koorata
Keyword(s):  
Numerical Investigation ◽  
Electrical Resistance ◽  
Gas Diffusion ◽  
Material Models ◽  
Bulk Electrical Resistance

scholarly journals Вплив параметрів адитивного формування на електричні властивості графітонаповненого композиту на основі полілактиду

2021 ◽  
Vol 150 (5) ◽  
pp. 93-102
Author(s):  
Н. В. Сова ◽  
О. О. Слепцов ◽  
Т. Р. Федорів ◽  
А. О. Мартиненко ◽  
М. Р. Кудлай ◽  
...  
Keyword(s):  
Electrical Properties ◽  
3D Printing ◽  
Electrical Resistance ◽  
Specific Resistance ◽  
Polymer Melt ◽  
Electrical Characteristics ◽  
Additive Production ◽  
Filled Composite ◽  
Printing Parameters ◽  
Bulk Electrical Resistance

Purpose. Investigate the effect of additive formation parameters on the properties of an antistatic composition based on polylactide (PLA). Methodology. Surface and bulk electrical resistance were determined by ASTM D257. Findings. The influence of additive formation parameters on the electrical properties of graphite-filled composite based on polylactide has been studied. It was found that the value of resistivity significantly depends on the printing conditions, namely the temperature, speed, thickness of the layer. Increasing the printing temperature helps to reduce the resistivity of the sample. Reducing the thickness of the polymer layer also reduces the resistivity at a print speed within 3000 mm / min It was found that the specific electrical characteristics are significantly different in the plane of the sample in contact with the printing platform. Concentric method of laying layers of polymer melt is less effective in terms of resistivity than mutually perpendicular. It was found that the electrical resistivity of samples made of material for 3D printing, which was previously subjected to drying below the resistance of the sample made of undried material. The programmed change of 3D printing parameters allows to control the specific resistance of graphite-filled composite based on polylactide in the range of three orders and to obtain products with properties from antistatic to statically dissipative materials. Additive production allows to obtain products of the desired configuration with adjustable electrical properties. Originality. The peculiarities of the change of antistatic properties of the polymer composite depending on the conditions of additive formation of experimental samples are investigated. Depending on the applied parameters of additive molding, it is possible to obtain products with properties from antistatic to statically dissipative materials. Practical value. Technological modes of additive molding of composite products based on polylactide and graphite have been developed. Energy consumption for additive formation of products of different mass is estimated.

Comparative experimental and numerical investigation of a piloted turbulent natural-gas diffusion flame

1994 ◽  
Vol 25 (1) ◽  
pp. 1241-1248 ◽  
Author(s):  
T.W.J. Peeters ◽  
P.P.J. Stroomer ◽  
J.E. de Vries ◽  
D.J.E.M. Roekaerts ◽  
C.J. Hoogendoorn
Keyword(s):  
Natural Gas ◽  
Numerical Investigation ◽  
Diffusion Flame ◽  
Gas Diffusion

Separate Measurement of Current Density Under the Channel and the Shoulder in PEM Fuel Cells

2007 ◽  
Author(s):  
Lin Wang ◽  
Hongtan Liu
Keyword(s):  
Fuel Cells ◽  
Diffusion Layer ◽  
Current Density ◽  
Electrical Resistance ◽  
High Current Density ◽  
Gas Diffusion Layer ◽  
Pem Fuel Cells ◽  
Gas Diffusion ◽  
Proton Exchange ◽  
Experimental Results

In a proton exchange membrane (PEM) fuel cell current density under the shoulder can be very different from that under the gas channel and the knowledge of where the current density is higher is critical in flow field designs in order to optimize cell performance. Yet, up to date this issue has not been resolved. In this study, a novel yet simple approach was adopted to directly measure the current densities under the channel and the shoulder in PEM fuel cells separately. In this approach, the cathode catalyst layer was so designed that either the area under the shoulder or the area under the channel was loaded with catalyst. Such a design guaranteed the currents generated under the shoulder and the channel could be measured separately. Experimental results showed that the current density produced under the channel was lower than that under the shoulder except in the high current density region. To determine whether the lateral electrical resistance of the gas diffusion layer (GDL) was the causes for lower current density under the channel, an additional set of experiments were conducted. In this set of experiments, a silver mesh was added on the top of the gas diffusion layer (GDL) and the experimental results showed that GDL lateral electrical resistance was not the cause and it had a negligible effect on lateral current density distribution.

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