Fuel cells have become an attractive choice because they do not cause environmental and noise pollution. Additionally, they do not contain any moving parts and have higher efficiency than fossil fuels. Therefore, improving the capability of fuel cells helps to provide clean energy. Among fuel cells, the proton exchange membrane fuel cell (PEMFC) includes five main parts that are end plate, membrane, gas diffusion layer (GDL), catalyst layer (CL), bipolar flow plate (BFP). End plates hold PEMFC parts together securely. They should have high mechanical strength and low density properties. Therefore, the choice of materials for the PEMFC endplate is important. The calculated values of fracture energy show quantitatively how much energy must be placed in the sample to create the fracture surface. In this study, a finite element study was performed to understand the fracture behavior of cracks in the selected materials under different loading angles. The results revealed that the total fracture energy of aluminum was higher than boron-aluminum 50 and boron-aluminum 65 composites.
Favourable efficiency of diesel engines makes them the most abundant type of internal combustion engines. However, diesel engines are also primary sources of particulate matter (PM) and nitrogen oxides (NOX) emissions formed as a result of the combustion process. There are many variables to affect the performance of diesel engine. One of them is injection pressure. Combustion process has a crucial effect on emission formation of diesel engines and this process is highly affected by fuel atomization. Injectors are one of the most important components of diesel engines that control the atomization of fuel. Today's modern injectors provide high injection pressures to improve fuel atomization. To reduce exhaust emissions and fuel consumption, the effect of high-pressure fuel injection was investigated in fourcylinder engines numerically. Increased injection pressure improves smoke and fuel consumption, especially at low and medium speeds. However, some variables can be adversely affected by pressure increases. In this study, variables affecting engine performance were observed at different injection pressures for 500-800 bar and 800-1000 bar, and the results were shared.
Polymer matrix composites are the most prevalent ones among all the composite materials because they offer high specific strength to weight ratio, toughness, and ease of processing. These composites own most of their properties to the high-strength reinforcement materials as carbon, glass, and aramid fibers. The mass production method of such composites is basically the sheet molding compound (SMC) compression molding technology. However, regarding the inherent defects of SMCs, such as porosities and internal cracks, the current trend of improving their performance requires a thorough understanding of mechanical and fracture properties of such products. Therefore, in this work, the commercially available chopped glass-fiber reinforced polyester SMC has been subjected to uniaxial tensile and mixed-mode fracture experiments, along and perpendicular to the rolling direction. The results of these experiments were employed as input data in a finite element model to determine the fracture toughness (KIC and KIIC) and critical strain energy release rate (GIC and GIIC) of material under mixed-mode loading conditions. Overall, although the reinforcing material were in the form of strands of glass fiber, SMC specimens exhibited lower mechanical properties and fracture toughness in transverse direction as compare with that of the longitudinal (rolling) direction under all modes of loadings.
Fossil fuels are used for energy procurement widely, so environmental pollution rises due to harmful gases release. The usage of clean energy sources has started to increase in order to prevent environmental pollution. For this reason, fuel cells have seen as a significant option among clean energy sources with its positive sides. Besides, research and development on fuel cells have become important issue. There are advantages of fuel cell's properties such as, being environmentally and friendly, not producing harmful gases, high efficiency, noiseless, no moving parts and therefore low maintenance required. At First, fuel cells were used in space and marine technology, usage of them has started to become more widespread with the great advances in fuel cells [1,2].Fuel cells are devices that convert chemical energy to electrical energy directly. They generally produce electricity and water by the reaction of Hydrogen and Oxygen. As a result of chemical reaction, they do not create harmful waste for the environment. Only water and heat are produced after chemical reaction, it is the most important feature of fuel cells in energy production [2-5].Generally, fuel cells are classified as Alkaline Fuel Cell (AFC), Direct Methanol Fuel Cell (DMFC), Proton Exchange Membrane Fuel Cell (PEMFC), Phosphoric Acid Fuel Cell (PAFC), Molten Carbonate Fuel Cell (MCFC) and Solid Oxide Fuel Cell (SOFC). Each of them has advantages with their specific features according to usage areas. PEMFC is used more widely today than other fuel cells. With its high voltage, current and power density, low pressure operation, corrosion-resistant electrolyte usage, tolerance to pressure change, simple structure, low temperature operation, portable usage, it is more accurate choice than the other fuel cells with its advantages [2,6,7].Metal, non-metal and composite materials are used as material of end plates in fuel cells. Composite materials are also preferred in fuel cells due to their light weight, corrosion resistance and high mechanical properties [8]. There are studies with composite on bipolar flow plates and end plate
In the current days, fuel cells are more preferred to generate electricity due to their positive sides. Because, if they use hydrogen and oxygen as fuel, they only produce electricity, heat, and water. This property of fuel cells is significant because it prevents environmental and chemical pollution, therefore, they contribute positively to the environment. In addition, they have more positive aspects such as having no moving or rotating parts. Therefore, they don't require mechanical maintenance and don't make noise. Besides, they can be used in a wide range of areas as mobile and stationary power sources for electricity generation. There are many fuel cell types but proton exchange membrane fuel cell (PEMFC) is more common than the other fuel cell types. It consists of parts such as an endplate, bipolar flow plate, gas diffusion layer, catalyst layer, and membrane. End plates are located on the outer side of PEMFC and hold together its stacks. In the design of the endplates, the state of fracture energy should be considered in different loading conditions. Because the material may fail if it is designed only for the strength of materials concepts. In this paper, pure mode I, pure mode II and mixed mode fracture energy behavior of different materials were investigated numerically by using Arcan specimen.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.