What are designs of insert of composite high pressure vessel?5 answersThe designs of inserts for composite high-pressure vessels vary based on the specific construction. One design involves a metal nozzle at the inlet of a plastic liner, with a corresponding insert and nut member for attachment. Another design includes a supporting body, a metal end with a mounting hole, a bottle opening valve, and an enhancement layer for reinforcement. Additionally, a novel high-pressure composite gas cylinder features an inner liner with sealing structures, top and bottom tapes for fixation, and a winding layer for added strength. These designs aim to enhance structural integrity, sealing performance, and pressure-bearing capabilities while ensuring lightweight construction.
How do nanocomposites improve the performance and durability of marine materials, such as boat hulls and fishing gear?5 answersNanocomposites play a crucial role in enhancing the performance and durability of marine materials like boat hulls and fishing gear. By incorporating nanoparticles into the materials, nanocomposites offer benefits such as reduced fuel consumption, lower pollutants, increased efficiency, and improved mechanical strength. Additionally, nanofillers in polymer matrices provide lower water intake, comprehensive chemical resistance in ionic environments, and delay the aging of structures in offshore applications. These advancements make nanocomposites ideal for marine applications, offering improved properties like higher viscoelasticity, tunable physical and chemical characteristics, and enhanced resistance to degradation in water. Overall, the utilization of nanocomposites in marine materials leads to increased efficiency, durability, and performance, making them valuable assets in the marine industry.
How does the use of composite materials in marine applications impact the durability and longevity of marine structures?5 answersThe utilization of composite materials in marine applications significantly influences the durability and longevity of marine structures. Composite materials, such as glass fiber reinforced composites, are exposed to harsh marine environments, leading to water absorption and subsequent degradation of mechanical properties over time. Green composites, made from biodegradable materials, offer a sustainable alternative, reducing the environmental impact and carbon footprint of marine structures. These materials exhibit resistance to degradation in water, making them suitable for various marine components like hulls, propellers, and subsea structures, enhancing longevity and reducing maintenance requirements. Understanding the impact of immersion time and operational temperature on composite materials is crucial for ensuring the long-term performance and structural integrity of marine applications.
Whats the metal matrix composites?5 answersMetal matrix composites (MMCs) are composite materials in which reinforcing particles or flakes are incorporated into a metal or alloy matrix to create a new material with enhanced properties. These composites are used in various industries such as transportation, aerospace, and automobile due to their desirable properties like tensile strength, stiffness, hardness, fatigue, and wear resistance. Different processing techniques have been developed to incorporate reinforcements of varying sizes into the metal matrix, including micron to nanometer sizes. Some of the commonly used manufacturing processes for MMCs include solid-state processing methods like powder metallurgy and liquid processing methods like stir casting. The mechanical properties of MMCs produced by different manufacturing techniques have been extensively studied. Metal matrix composites find wide applications in manufacturing due to their lightweight nature and excellent surface and mechanical characteristics.
Whats the polymer composites?4 answersPolymer composites are materials that consist of a polymer matrix reinforced with other materials such as glass, carbon, or nanocomposites. These composites are used in various industries including automotive, aerospace, biosensing, and electronics applications. In the automotive industry, polyester polymer resin is commonly used as the matrix for polymer composites. In biosensing, polymer nanocomposites with integrated nanoparticles are used to improve performance features such as rapid response and high selectivity. Composite materials based on synthetic polymers have unique properties such as thermal and mechanical stability, good selectivity, and cost-effectiveness, making them suitable for various applications including wastewater treatment and ion-exchange membranes. Polymer matrix composites are also widely used in electronics applications, offering properties such as strength, rigidity, thermal conductivity, and desirable dielectric properties. Additionally, composite films consisting of polymer layers and heat seal compositions are used for packaging and heat-sealing applications.
How does the blockage effect of a short duct affect the propeller noise?5 answersThe blockage effect of a short duct can significantly benefit noise control for propellers. Installing the propeller at the symmetric plane of the duct can achieve the most noise reduction. The blockage effect can also affect the cavitation pattern on the blade surface, especially when cavitation is intense. The Glauert formula can satisfactorily correct thrust, torque, and hydrodynamic efficiency even in moderate cavitation, but it is not recommended when cavitation is intense. The presence of an incoming airflow can modify the noise radiation of a ducted propeller, both in the frequency and spatial domain. The ground effect near the ducted propeller can lead to a high-pressure zone that blocks the jet flow through the outlet of the duct, affecting the aerodynamic forces and powers of both the duct and propeller. The ground effect should be considered in the process of aerodynamic and conceptual design for ducted propellers in near ground hover state.