This paper presents a numerical study of natural convection in an annular cavity filled with a hybrid nanofluid under the influence of a magnetic field. This study is significant for applications requiring enhanced thermal management, such as in heat exchangers, electronics cooling, and energy systems. The inner cylinder, equipped with fins and subjected to uniform volumetric heat generation, contrasts with the adiabatic outer cylinder. This study aims to investigate how different nanoparticle combinations (Fe3O4 with Cu, Ag, and Al2O3) and varying Hartmann and Rayleigh numbers impact heat transfer efficiency. The finite volume method is employed to solve the governing equations, with simulations conducted using Fluent 6.3.26. Parameters such as volume fraction (ϕ2 = 0.001, 0.004, 0.006), Hartmann number (0 ≤ Ha ≤ 100), Rayleigh number (3 × 103 ≤ Ra ≤ 2.4 × 104), and fin number (N = 0, 2, 4, 6, 8) are analyzed. Streamlines, isotherms, and induced magnetic field contours are utilized to assess flow structure and heat transfer. The results reveal that increasing the Rayleigh number and magnetic field enhances heat transfer, while the presence of fins, especially at N = 2, may inhibit convection currents and reduce heat transfer efficiency. These findings provide valuable insights into optimizing nanofluid-based cooling systems and highlight the trade-offs in incorporating fins in thermal management designs.
This study presents numerical analyses of the thermal, metallurgical, and mechanical processes involved in welding. The temperature fields were computed by solving the transient heat transfer equation using the ABAQUS/Standard 2024 finite element solver. Two types of moving heat sources were applied: a surface Gaussian distribution and a volumetric model, both implemented via DFLUX subroutines to simulate welding on butt-jointed plates. The simulation accounted for key welding parameters, including current, voltage, welding speed, and plate dimensions. The thermophysical properties of the INC 738 LC nickel superalloy were used in the model. Solidification characteristics, such as dendritic arm spacing, were estimated based on cooling rates around the weld pool. The model also calculated transverse residual stresses and applied a hot cracking criterion to identify regions vulnerable to cracking. The peak transverse stress, recorded in the heat-affected zone (HAZ), reached 1.1 GPa under Goldak’s heat input model. Additionally, distortions in the welded plates were evaluated for both heat source configurations.
In this article, we present an investigative study on the often-overlooked partial wake phenomenon in previous studies concerning wind farm configurations. A partial wake occurs when a portion of the actuator disk of a downstream wind turbine is affected by the wake of another upstream turbine. This phenomenon occurs in addition to the full wake, where the entire upstream turbine is affected by the wake of the frontal turbine, also leading to a decrease in wind speed and consequently a reduction in power production. The proposed study is based on measuring the power generated by the area swept by the wake of an array of turbines in a wind farm. To accomplish this, we integrate the linear wake model of Jensen, the specifications of the ENERCON E2 wind turbine, and the wind farm data into Matlab-developed software (version 18) to perform the calculations. In a concrete application, this proposed method is validated by reproducing the previous works that neglected the partial wake in wind farm configurations. The simulation results obtained are analyzed, compared, and discussed under similar operational conditions.
3 February 2025 in International Journal of Structural Integrity
Purpose: This study aims to develop high-performance truck trailer supports using polyamide PA6, a thermoplastic material renowned for its mechanical strength, durability and adaptability to extreme conditions. By analysing the material’s properties and exploring manufacturing methods such as injection moulding and 3D printing, the research seeks to optimise the design and production of supports capable of withstanding heavy-duty mechanical stresses. The ultimate goal is to provide the transport industry with reliable, cost-effective and durable solutions that meet safety standards and performance demands, ensuring enhanced operational efficiency and resilience in challenging environments.Design/methodology/approach: The study investigates the design and production of truck trailer supports using polyamide PA6, chosen for its high mechanical strength, thermal stability, and resistance to wear and chemical exposure. The research evaluates manufacturing techniques, including injection moulding and 3D printing, to optimise part performance and durability under heavy-duty mechanical stresses. Emphasis is placed on designing supports capable of enduring harsh environmental conditions while ensuring safety and cost-efficiency. By leveraging the superior properties of PA6, the study aims to develop reliable solutions that meet the transport industry’s stringent performance and economic requirements.Findings: The study confirms that using PA6 polyamide for truck trailer supports is an innovative and cost-effective solution, offering superior mechanical performance and environmental resistance. A detailed analysis of PA6 properties and manufacturing methods reveals its suitability as a robust and durable alternative for trailer supports. This integration marks a significant advancement in improving trailer efficiency and performance while maintaining quality standards. The findings underscore the importance of leveraging technological advancements to address challenges in innovation and sustainability, supporting the growth of the transport and logistics sector.Originality/value: This study introduces an innovative approach to designing truck trailer supports by utilising polyamide PA6, highlighting its superior mechanical properties and environmental resilience. By combining material analysis with advanced manufacturing techniques, such as injection moulding and 3D printing, the research provides a novel framework for producing durable, cost-effective components tailored to the transport industry’s demands. The originality lies in the integration of PA6 into heavy-duty applications, showcasing its potential to enhance performance, efficiency and sustainability. This work adds significant value by addressing critical industry challenges and offering practical solutions that align with modern safety and environmental standards.
1 December 2022 in Acta Universitatis Sapientiae, Electrical and Mechanical Engineering
Inconel738 is a nickel-based super alloy widely used in manufacturing gas turbines, particularly in the manufacture of blades that are in direct contact with hot gases during their operation. As a result, these blades are subjected to high temperatures, significant static and dynamic stresses, erosion and/or hot corrosion which can be very severe. The use of coatings is one of the most effective strategies to protect materials against corrosion and increase the wear resistance of materials. In this study, β-Ni-Al coatings were sprayed onto an Inconel738 substrate using a wire flame spraying process and characterization of coating has been made.
This study presents a quantitative comparison between the Jensen and Ishihara wake models to assess their impact on power output in wind farms. Both models were applied in a MATLAB-based simulation environment using pseudo-random number generation to optimize the configuration of 30 ENERCON E2 turbines on a 100-cell grid. Wind speeds between 7 m/s and 12 m/s were simulated. The Ishihara model predicted 57.96 MW at 12 m/s, corresponding to a 2.09% reduction in power, while the Jensen model predicted 55.71 MW, corresponding to a 5.89% reduction. For the Jensen model, the wake radius at x/D=10 was 4.53; for the Ishihara model, it was 2.05. The results show that the Ishihara model provides more accurate predictions of wake behavior and energy yield. At wind speeds close to the rated value (13 m/s), where wake effects become insignificant, both models agree. These results highlight the need to select an appropriate wake model in the design of wind farms to achieve optimal turbine placement and accurate energy predictions.