3rd World Conference on Mechanical Engineering

composites have become increasingly popular in orthopedic structures due to their high strength-to-weight ratio and biocompatibility. These materials are commonly used in implants, prosthetics, and other orthopedic devices However, the long-term performance and durability of carbon composites in biomedical applications are not fully understood, there for this study discus the Aging of two different type of resins corthocryle and polyester, against aggressive environment diesel in this case in order to determine weight gaining or loss, particularly at the microscopic level ,The specimens were exposed to diesel and weighed weekly for one months, resulting in four measurements for each medium. A microscopic study (MEB) was conducted to better understand the weight gain phenomena. The results were compared to assess the aggressiveness of the liquid on both resins. The liquid absorption curves did not follow the Fickian type, instead showing progressive absorptions followed by leaching at the end of the experiments for the polyester resin. On the other hand, a desorption observed for c-orthocryl resin. Polyester had greater absorption than c-orthocryl, while resin corthocryl exhibited faster physical leaching despite lower absorption. The microscopic study revealed preferential paths for liquid propagation in the material, attributed to the resin proprieties and the infusion molding process used.

In today's gas turbines, the purge flow plays a critical role in enhancing turbine performance by limiting the ingestion of hot gases into the cavity located at the stator / rotor interface. The aerothermal efficiency of this method is fundamentally affected by various geometric and physical parameters. This study presents a 3D CFD simulation that investigates the influence of the slot width (E) on the cooling performance and aerodynamic losses of a high-pressure transonic gas turbine, in which four geometries are studied by using the commercial software ANSYS Fluent (two uniform slot geometries with E= 2 mm and 3 mm, and two converging slot geometries 𝐸2/𝐸1 = 0.5 and 𝐸2/𝐸1 = 0.75), setting the slot inclination angle (𝝓) to 30° and the purge flow rate to 1%. The Reynolds-averaged Navier-Stokes (RANS) equations for steady flow are solved using the k-ω SST turbulence model. The results obtained indicate that the converging slot configuration with 𝐸2/𝐸1 = 0.5 is the most adequate choice.

In the demanding operating environment of gas turbines, particularly in the first stage where temperatures reach extreme levels, turbine vanes are subject to intense thermal stress. Film cooling is a critical technique, forming a protective layer that reduces exposure to the intense temperature generated during combustion. An ANSYS CFX numerical simulation was run to study flow behavior through leaned NGV turbine. The key objective was to carry out a comparative study investigating the effect of the presence of the cooling system, one utilizing cooling holes with two distinct inclination angles 25 and 30 degree, at the same mass flow rates (MFR) of 0.5 and the other incorporating slot, ensuring that both cooling methods were positioned alike for a close comparison. In addition, the study investigated the influence of different mass flow rates (MFR) of 0.5, 1, 1.5 and 2 for the case of 30 degrees. The study highlights a significant reduction in hub temperature from 1704.0845 K (30-degree hole) to 1627.85 K (slots only), reflecting considerable effectiveness of the different cooling methods. Pointing to the mass flow rate’s importance in optimizing cooling performance.

The longevity and precision of astronomical observations hinge on the optimal performance of antenna structures, yet the open atmosphere poses a persistent threat of corrosion to vital components. The Quadripod (QPD) structure of the C03 antenna at the Giant Meter wave Radio Telescope (GMRT) has succumbed to significant corrosion in 20 years, compelling an urgent need for replacement. This paper introduces an innovative approach to combat corrosion through the design of required structures, specifically focusing on Columns. Additionally, the paper details the meticulous design of essential components, including lifting and resting mechanisms, to facilitate the seamless replacement of the antenna. The proposed design addresses safe lowering and lifting of the antenna. This paper contributes a comprehensive solution to safeguard against corrosion-induced degradation and lays the foundation for sustained excellence in radio telescope operations. The column design is strategically engineered to allocate the load-bearing responsibility among three out of four columns, ensuring the safe lowering of the antenna structure. This paper delves into the preliminary considerations for maintaining damaged pipes at the Quadripod (QPD) of the antenna. Our investigation involves the development and analysis of three distinct configurations aimed at addressing corrosion issues within the QPD structure. Out of these configurations, one has been adopted for the replacement of the QPD structure. In conclusion, the innovative approach presented in this paper not only addresses the urgent need for replacement of the corroded Quadripod structure at the Giant Metre wave Radio Telescope (GMRT), but also showcases our in-house technical expertise in combating corrosion-induced degradation. By meticulously designing essential components and implementing strategic engineering solutions, we have laid the foundation for sustained excellence in radio telescope operations. Our commitment to pushing the boundaries of innovation and ensuring optimal performance underscores our dedication to advancing astronomical observation capabilities.

In this paper, the problem of predicting creep-failure time of thick-walled spherical vessels is investigated. The thick-walled spherical vessels are important structural components that are used in many industries such as oil, chemical, and nuclear industries, etc. and are required to operate under complex thermal and mechanical loadings where creep deformation is prevalent. The fact that continuing deformation under creep may reach a value where the assumption of small strains becomes increasingly invalid has been incorporated by using a finite-strain formulation in the mathematical framework developed to perform the creep-failure prediction times of the vessels. The mathematical analysis is conducted by employing the equilibrium, compatibility, and constitutive equations for the finite (logarithmic) strain theory together with suitable boundary conditions. The creepfailure time prediction relation is developed and solved using analytical and/or numerical methods. The special cases of thin-walled and very thick-walled spherical vessels are discussed, and the creep-failure time relations are derived for them. Parametric studies for various wall thicknesses and pressure magnitudes are performed and presented in the form of graphs. It is expected that this investigation will provide useful guidelines for predicting more accurate creep- failure time and thus result in a safer design of thick-walled spherical vessels.

The marine industry is using many types of alternative Polymer-based composite materials in the manufacture of small tourist boats, fishing boats and military boats due to the impact of the harsh marine environment on metallic materials. There’s a lot of research have been conducted or still ongoing for the possibility of using others types of resins non-degradable resins in marine composites, to achieve a fundamental understanding of how Fuel interact with the Polymer, In this research, two types of resin polyester resin and c-orthocryl resin were subjected to fuels (Gasoline) absorption test, absorption test were conducted by immersing specimens into Gasoline at room temperature from 1st day until 4th week, the absorption of the gasoline by two Polymers was captured and compared. The weight gain by the polyester due to absorption was low but was different for the other C-orthocryl. The absorption of model fuel decreased the mechanic propriety of composites. The change in Absorption was significantly different between the polyester resin and the C-orthocryl resin these results can be making C-orthocryl not possible substitute for the polyester resin in the naval industry; the phenomenon of gasoline absorption is discussed after 1 month, Scanning electron microscope was used to investigate the microscopic mechanisms of absorption and damage and were used to determine the change in the polyester & c-orthocryl after immersion in Gasoline solutions.

The present investigation introduces a novel micro-combustor for micro-thermophotovoltaic application. The micro-combustor is a modified version of the conventional Micro Backward Step Combustor (MBSC) and features an additional aft-body to create a trapped vortex. The novel micro combustor is called a Micro Trapped Vortex Combustor (MTVC). This design is inspired from the propulsion and power combustion systems and its suitability for micro-scale application will be assessed using computational fluid dynamics. The investigations are carried out under laminar flow regime, conjugated heat transfer, premixed hydrogen-air, lean combustion and various inflow velocities. The results indicate that the trapped vortex design is very suitable for micro-combustor application since it enhances the flame stability compared to the conventional design. The twin vortices formed in the cavity and downstream the aft-body are responsible of increasing the combustion intensity as the inflow speed increases. Consequently, both the conductive and radiative heat transfers are intensified through the bottom wall, which is very beneficial to micro-thermophotovoltaic systems. Moreover, it was found that the novel MTVC is capable of maintaining combustion at an ultra-lean regime up to Φ = 0.5. More importantly, comparison between both configurations at Φ = 0.8 revealed that the MTVC produces 47% less NOx compared with the MBSC.