https://www.um.edu.mt/library/oar/handle/123456789/902 Sun, 12 Apr 2026 20:48:43 GMT 2026-04-12T20:48:43Z https://www.um.edu.mt/library/oar/handle/123456789/145008 Title: Progress in the concept development of the VNS — a beam-driven tokamak for component testing Authors: Bachmann, Chris; Siccinio, Mattia; Aiello, Giorgia; Ambrosino, Roberto; Bajari, J.; Boscary, J.; Carusotti, S.; Claps, V.; Cufar, A.; Elbez-Uzan, J.; Federici, G.; Franke, T.; Giannini, L.; Gliss, C.; Haertl, T.; Hopf, C.; Luongo, C.; Maione, I.; Maisonnier, D.; Marzullo, D.; Maviglia, F.; Marek, P.; Mollicone, Pierluigi; Moscato, I.; Mozzillo, R.; Muscat, Martin; Pagani, I.; Park, J.H.; Pereslavtsev, P.; Quartararo, A.; Renard, S.; Steinbacher, T.; Tarallo, A.; Vallone, E.; Vigano, F.; Wiesen, S.; Wu, C. Abstract: The Volumetric Neutron Source (VNS) is a compact beam-driven tokamak with D–T plasma to generate a high neutron flux that will allow the testing and qualification of fusion nuclear components, in particular the breeding blanket. Recently, EUROfusion concluded a design study that confirmed the feasibility of VNS for construction and operation. Also, aspects were identified that require further development and assessment, and these have been key subjects of the on-going conceptual design phase. This article summarises the progress made in the design of VNS, including the rationale for the small adjustments of major radius and aspect ratio, the configuration and performance of the equilibrium coils, the design of the in-vessel components including their remote handling concepts, (vi) design of the nuclear buildings and layout of the main plant systems including those related to the fuel cycle. Thu, 01 Jan 2026 00:00:00 GMT https://www.um.edu.mt/library/oar/handle/123456789/145008 2026-01-01T00:00:00Z https://www.um.edu.mt/library/oar/handle/123456789/143783 Title: Examining the effects of different winglet designs on aerodynamic forces using computational fluid dynamics Abstract: The pursuit of better aerodynamic efficiency in aircraft design has led to significant advancements, with winglets being one of the most impactful innovations. Winglets are aerodynamic extensions at the tips of an aircraft’s wings designed to reduce induced drag by minimizing wingtip vortices. This reduction in drag improves lift-to-drag ratios, leading to fuel savings, extended range, lower carbon emissions, and quieter flight operations. Over time, various winglet designs have emerged, including bio-inspired configurations, each offering distinct aerodynamic advantages. While traditional wind tunnel tests remain useful, Computational Fluid Dynamics (CFD) has become essential for optimizing winglet geometry, providing insights into flow fields and aerodynamic forces under various conditions. Despite progress, designing universally optimal winglets remains challenging due to the need to balance lift, drag, structural strength, and manufacturing feasibility. This thesis uses CFD to examine the effects of different winglet geometries on aerodynamic performance, contributing to a deeper understanding of their impact on efficiency. First, an intensive review of the current literature related to CFD studies of winglets was carried out. The different setups used in literature combined with further information obtained through background theory research were used to determine the set up used for the simulations carried out in this thesis. Within this study, no winglet, raked winglet, fenced winglet, blended winglets and split winglet models were analysed. In this thesis, the end section of the winglet attached to the full wing geometry and the end geometry by themselves were analysed and compared. These results provided similar trends for both geometries, with the raked winglet providing the highest lift-to-drag ratio, followed closely by the blended winglet. From this study, the split and fenced winglet provided the lowest values of lift-to-drag ratio meaning that these winglets were the least efficient. Furthermore, to analyse clearly the trailing vortices formed behind the winglet, another set of simulations were carried out with the same geometry and domain, only editing the mesh to be more refined behind the wing. This resulted in a more clear display of the vortices, making it easier to compare how the different winglets effected the formation of these vortices. The effect of the Cant angle on blended winglets was also analysed, to see which model produced the best lift-to-drag ratio. The results were very close to each other. The 45° Cant angle winglet produced the best results, closely followed by the 30° Cant angle model and lastly by the 60° Cant angle model. Description: B.Eng. (Hons)(Melit.) Wed, 01 Jan 2025 00:00:00 GMT https://www.um.edu.mt/library/oar/handle/123456789/143783 2025-01-01T00:00:00Z https://www.um.edu.mt/library/oar/handle/123456789/143782 Title: CFD modelling of the indoor unit of an air conditioner Abstract: Air conditioning (AC) systems are crucial for maintaining thermal comfort and indoor air quality. With the growing demand for efficient cooling, understanding AC unit performance is crucial for improving efficiency and reducing operational costs. Monitoring airflow dynamics is key to optimizing system design and energy efficiency. This study investigates the airflow behaviour within a split-type indoor air conditioning (SAC) unit using computational fluid dynamics (CFD) modelling, supported by experimental validation. A two-dimensional transient CFD model was developed in ANSYS Fluent 2024 R2 software to simulate airflow at three different fan speeds. The CFD analysis revealed several critical airflow patterns within the indoor SAC unit, including three major recirculation zones: an eccentric vortex at the periphery of the impeller, a recirculation zone at the intake of the impeller near the rear wall and another at the unit outlet. The eccentric vortex, formed by the interaction between the rotating fan and the stationary vortex wall, created low-velocity regions and reversed flow. Additional recirculation zones formed due to flow disruptions caused by internal components including the rear and vortex walls, while stagnation regions around sharp geometries indicated potential obstructions or redirection of airflow. The recirculation zones contributed to the displacement of the eccentric vortex, thereby reducing discharge efficiency and affecting overall air delivery. The highest velocity occurred along the rear wall due to centrifugal force, resulting in a jet flow that remained attached to the rear wall. Although the shape of the jet flow deviated from typical CFD literature, it was supported by experimental observations, emphasizing the importance of realworld validation. Overall, this study demonstrates the effectiveness of CFD in capturing key airflow behaviours in indoor SAC units and provides a basis for further research on optimizing airflow performance. Description: B.Eng. (Hons)(Melit.) Wed, 01 Jan 2025 00:00:00 GMT https://www.um.edu.mt/library/oar/handle/123456789/143782 2025-01-01T00:00:00Z https://www.um.edu.mt/library/oar/handle/123456789/143781 Title: Comparative analysis and validation of different measurement technologies for vertical jump performance Abstract: Force plates (FP) are a primary tool used by the Malta Olympic Committee (MOC) in the Functional Diagnostic Lab (FDL) to assess vertical jump performance in athletes, particularly through the countermovement jump (CMJ) and the multi-rebound jump (MRJ) tests. The main aim of this dissertation is to develop a custom-built software to extract previously unattainable performance metrics from the MRJ test. The double integration method, using numerical trapezium integration, proved to be a viable approach to replicate CMJ performance metrics. However, this method is unsuitable for MRJ analysis due to integration drift, which introduced significant inaccuracies in deriving performance metrics. As a result, the flight time method was adopted as the preferred method for MRJs. The initial version of the software evaluated two force threshold methods to detect the take-off and landing instants. The first method employed a standard deviation method, while the second method applied a 10 N threshold on one leg. Both approaches replicated nearly all the metrics to within a 5% error. Following consultation with the FP manufacturer (Hawkin Dynamics) it was identified that their FP use a 25 N force threshold. Therefore, the final version of the software implemented this threshold which replicated the metrics to a near zero percent error when compared to the FP outputs. A secondary objective is to validate the use of FP using alternative technologies. Three motion capture methods were compared to assess discrepancies in different jump height definitions which resulted in discrepancies ranging from 4 cm up to 16.5 cm. These findings highlighted the importance of defining the jump height relative to the measurement technology used. When comparing the force threshold methods against motion capture technology, the standard deviation method proved most accurate, underestimating jump height by ~0.6 mm on average, and is best suited for symmetrical jumpers. Although the single leg 10 N threshold overestimated jump height by ~6.1 mm and the 25 N by ~4.2 mm, they aligned best with the FP software. All methods produced consistent results across 11 tests. Additionally, the smartphone accelerometer overestimated jump height by ~1 cm, showing improved accuracy over previous research, but was deemed unsuitable for FDL use due to limited reliability and automation. Therefore, the FP were still considered the gold standard for assessing vertical jump performance in the FDL at the MOC. Description: B.Eng. (Hons)(Melit.) Wed, 01 Jan 2025 00:00:00 GMT https://www.um.edu.mt/library/oar/handle/123456789/143781 2025-01-01T00:00:00Z