1,721,027 research outputs found
Propagating vortices in ferrofluidic Couette flow under magnetic fields - part II: Oblique orientated fields
Full text linkThis work provides a numerical investigations of propagating vortex flow states (pVs) for ferrofluidic Couette flow with small aspect ratio and fixed non-rotating end-walls. The system is subjected to oblique magnetic fields as superposition of axial and transverse orientated fields. Such field configuration breaks the basic system symmetries and renders all flow structures to be inherently three-dimensional with complexer flow dynamics. Under oblique field configuration pV states are not direct present at onset. Instead oscillating flow states (oVs) bifurcate out of the stationary state. Basically these oVs hold same symmetries as pVs, which eventually evolve in a smooth transformation out of the oVs. pVs under oblique fields appear periodic or quasi-periodic, which render them topological speaking to exist on either two- or one-dimensional invariant manifolds as 2-torus or limit cycle (1-torus) solutions, respectively. In detail, structural modifications and changes in spatial and temporal behavior for pV solutions are studied with changing the magnetic field strength of the applied magnetic field.Postprint (author's final draft
Optimization of Genetic algorithm as multi-gravity assist design tool
No full textThis master thesis presents an enhancement of the outer loop in a genetic algorithm for interplanetary trajectory design. The outer loop, responsible for determining the sequence of planetary flybys, plays a critical role in the early stages of space mission planning. To support this process, a pre-processing module was developed in C++ to autonomously generate and filter feasible flyby sequences using heuristic rules, energy approximations, and a genetic algorithm framework. This significantly reduces the number of non-viable candidates and provides optimized inputs to the inner-loop algorithm, improving the overall efficiency of the trajectory design process. The full approach includes two levels of optimization: the outer loop selects promising flyby sequences based on feasibility and estimated energy cost, while the inner loop focuses on optimizing trajectory timing. Evaluation criteria include total delta-V and time of flight, which are crucial for balancing mission cost and duration. All tools were implemented to run from the command line, providing flexibility and automation with minimal user input. The system was tested using parameters from real missions such as Voyager I, Voyager II, and Galileo. The trajectories generated were physically consistent and realistic, showing structural and energetic profiles in line with actual mission data. A key contribution of this work is the reduction of manual configuration, this method allows the user to define high-level mission constraints and let the algorithm explore a broad solution space autonomously. Although some simplifications were necessary, the resulting framework is generalizable and modular, allowing future extensions or adaptations to different mission contexts. It represents a meaningful step towards a more automated design of interplanetary missions.Objectius de Desenvolupament Sostenible::9 - Indústria, Innovació i Infraestructur
Active flow control of airfoils via multi-sweeping jets at ultra low Reynolds numbers
No full textThe primary focus is on implementing multiple sweeping jets to eliminate the requirement for high-lift equipment with mechanical components, which are at risk for mechanical failures and increase weight due to redundant control mechanisms. This project deals with the investigation of aerodynamic and performance parameters of Airfoils under subsonic flow regimes. This mainly includes the Active flow control techniques such as multi-sweeping jets used in Airfoils that will help us analyse the lift and drag parameters. The jet configurations are studied and modified to reduce viscous drag, improve pressure distribution and interference effects over and below the airfoil, and maximize lift coefficient. Pre and Post-processing stages would include the generation of a complete airfoil design with built-in sweeping jets using Fusion 360. It requires parametric inputs like altering the position of jets in order to calculate the induced drag and thus decrease the drag effects. The use of this open source also results in advanced visualization capabilities that include pressure, velocity distribution, turbulent kinetic energy, and eddy viscosity contours of the airfoil. This analysis and simulation have been carried out using ANSYS Fluent, industryleading fluid simulation software.Objectius de Desenvolupament Sostenible::9 - Indústria, Innovació i Infraestructur
Evolution-estimation and tendency of the future power resources of aviation
No full textThis report primarily aims to estimate when and what type of resource is going to be the principal type of resource in charge of decarbonizing the aviation industry. Forced by the huge increase in operations experienced in the last 30 years, severely impacting the planet, making this situation unsustainable and prompting it to look for more renewable resources. Based on analysis, studies, and estimations of several parts of the industry, like regulators, manufacturers, and airlines, a compilation of them shows a probable way of development for the industry to invest among others to create new types of energies to power the aircraft. The estimation also relies on the technological advancements made so far as well as the expected ones in the near future to be implemented in the industry, while also considering the economic viability of the transition. The results show that a clearway wasn't defined for development a few years ago, looking for really radical changes in the industry like the implementation of electric and hydrogen-powered aircraft. Nevertheless, once the first tests were done using these resources, irrefutable and undeniable conclusions appeared, like the lack of technology available able to power commercial operations mainly because of range restrictions caused by the weight and occupancy of them inside the aircraft, limiting those solutions to very short-range flights, leaving them for further years like 2045 to be implemented. Once the industry realized that a small step was needed in the middle, collaboration from all parts, including support policies became essential for the implementation of SAF, taking advantage of the similarities to conventional fuels, making them a drop in solution for the reduction of emissions with the goal to be fully stabilized on operations by 2030, and 'only' needing to increase the rate of blending until arriving to a 100% and finding less harmful ways to produce them, making them the first-placed resource intended to reach the decarbonization goal in 2050.Objectius de Desenvolupament Sostenible::7 - Energia Assequible i No ContaminantObjectius de Desenvolupament Sostenible::13 - Acció per al Clim
Development of a hybrid propulsion system for fuel-efficient aircraft
No full textThis project focuses on studying the feasibility of introducing alternative energy sources into conventional aircrafts to reduce fossil fuel consumption. Currently, the use of electricity as the primary propulsion source for aircraft is not very viable due to the low energy density of actual batteries required to provide an aircraft with a practical range. For this reason, this study explores the introduction of electricity as a complement to fossil fuels to help reduce overall kerosene consumption. The initial idea of the project was to develop a hybrid system alongside existing turbofan engines. However, it became evident that electrification should be introduced gradually and naturally rather than being forced. Therefore, the project focuses on integrating electric energy into specific phases, such as taxiing from the stand to the runway threshold. Both the technological and economic feasibility have been analyzed, and the results are compared with current industry developments, such as the solution proposed by WheelTug. As part of the research, an interview was conducted with the company's current CEO to discuss the project, compare proposed solutions, and explore future industry expectations in the incoming years.Objectius de Desenvolupament Sostenible::7 - Energia Assequible i No ContaminantObjectius de Desenvolupament Sostenible::9 - Indústria, Innovació i Infraestructur
Aerodynamic analysis of a delta wing with active flow control
No full textDelta wing configurations are widely used in high-speed aircraft due to their favorable behavior at high angles of attack. However, they tend to perform poorly at low speeds, which poses challenges during maneuvers such as landing approaches or low-altitude flight. Among the available flow control strategies, the use of blowing jets offers a promising solution to improve performance under these conditions. Nevertheless, most previous research has focused on synthetic jets or two-dimensional airfoils, with few studies analyzing steady blowing jets on three-dimensional wing geometries. In this context, the objective of this project is to evaluate the effect of steady blowing jets on the aerodynamic performance of delta wings at low angles of attack. The study has been conducted through numerical simulations using Computational Fluid Dynamics (CFD). Two delta wing geometries, a Bicombex wing and a Wedge wing, were analyzed in both clean and actively controlled configurations. The simulations were performed using ANSYS CFX in steady-state mode, employing a pressure-based solver and the k-¿ turbulence model. Key aerodynamic parameters such as lift, drag, pressure distribution, and turbulent kinetic energy were extracted and compared. The results show a consistent improvement in aerodynamic efficiency with the activation of the jets, with an increase in the lift-to-drag ratio of over 4% in both configurations. While the Wedge wing produced more absolute lift, the Bicombex wing achieved slightly higher aerodynamic efficiency
Evolution-estimation and tendency of the future power resources of aviation
No full textThis report primarily aims to estimate when and what type of resource is going to be the principal type of resource in charge of decarbonizing the aviation industry. Forced by the huge increase in operations experienced in the last 30 years, severely impacting the planet, making this situation unsustainable and prompting it to look for more renewable resources. Based on analysis, studies, and estimations of several parts of the industry, like regulators, manufacturers, and airlines, a compilation of them shows a probable way of development for the industry to invest among others to create new types of energies to power the aircraft. The estimation also relies on the technological advancements made so far as well as the expected ones in the near future to be implemented in the industry, while also considering the economic viability of the transition. The results show that a clearway wasn't defined for development a few years ago, looking for really radical changes in the industry like the implementation of electric and hydrogen-powered aircraft. Nevertheless, once the first tests were done using these resources, irrefutable and undeniable conclusions appeared, like the lack of technology available able to power commercial operations mainly because of range restrictions caused by the weight and occupancy of them inside the aircraft, limiting those solutions to very short-range flights, leaving them for further years like 2045 to be implemented. Once the industry realized that a small step was needed in the middle, collaboration from all parts, including support policies became essential for the implementation of SAF, taking advantage of the similarities to conventional fuels, making them a drop in solution for the reduction of emissions with the goal to be fully stabilized on operations by 2030, and 'only' needing to increase the rate of blending until arriving to a 100% and finding less harmful ways to produce them, making them the first-placed resource intended to reach the decarbonization goal in 2050.Objectius de Desenvolupament Sostenible::7 - Energia Assequible i No ContaminantObjectius de Desenvolupament Sostenible::13 - Acció per al Clim
Optimization of Genetic algorithm as multi-gravity assist design tool
No full textThis master thesis presents an enhancement of the outer loop in a genetic algorithm for interplanetary trajectory design. The outer loop, responsible for determining the sequence of planetary flybys, plays a critical role in the early stages of space mission planning. To support this process, a pre-processing module was developed in C++ to autonomously generate and filter feasible flyby sequences using heuristic rules, energy approximations, and a genetic algorithm framework. This significantly reduces the number of non-viable candidates and provides optimized inputs to the inner-loop algorithm, improving the overall efficiency of the trajectory design process. The full approach includes two levels of optimization: the outer loop selects promising flyby sequences based on feasibility and estimated energy cost, while the inner loop focuses on optimizing trajectory timing. Evaluation criteria include total delta-V and time of flight, which are crucial for balancing mission cost and duration. All tools were implemented to run from the command line, providing flexibility and automation with minimal user input. The system was tested using parameters from real missions such as Voyager I, Voyager II, and Galileo. The trajectories generated were physically consistent and realistic, showing structural and energetic profiles in line with actual mission data. A key contribution of this work is the reduction of manual configuration, this method allows the user to define high-level mission constraints and let the algorithm explore a broad solution space autonomously. Although some simplifications were necessary, the resulting framework is generalizable and modular, allowing future extensions or adaptations to different mission contexts. It represents a meaningful step towards a more automated design of interplanetary missions.Objectius de Desenvolupament Sostenible::9 - Indústria, Innovació i Infraestructur
New winglet designs to minimize drag and turbulence
Full text linkThe aerospace industry relies on the continuous upgrading of available technology and the testing of novel concepts to ensure that there is a demand for aircraft design investments. These aircraft design improvements will substantially impact the aircraft's aerodynamic efficiency and structural design. Winglets are one of the essential components of an aircraft's design that contribute to its aerodynamic efficiency. The winglet design plays a significant part in reducing aerodynamic drag when it comes to the geometry of a wing. The winglet is responsible not only for the aircraft's efficiency but also for its structural integrity. So, based on the backdrop, as mentioned earlier, we'll now focus on implementing alternative winglet designs, generating parameters such as drag force and lift, and finally determining the most effective design based on the shape and flow regimes. Autodesk Fusion 360, Education License, the integrated CAD/CAM and 3D modeling software, is used to develop novel winglet designs. Ansys Fluent student version displays flow parameters, analysis, and simulations.Objectius de Desenvolupament Sostenible::9 - Indústria, Innovació i Infraestructur
New winglet designs to minimize drag and turbulence
Full text linkThe aerospace industry relies on the continuous upgrading of available technology and the testing of novel concepts to ensure that there is a demand for aircraft design investments. These aircraft design improvements will substantially impact the aircraft's aerodynamic efficiency and structural design. Winglets are one of the essential components of an aircraft's design that contribute to its aerodynamic efficiency. The winglet design plays a significant part in reducing aerodynamic drag when it comes to the geometry of a wing. The winglet is responsible not only for the aircraft's efficiency but also for its structural integrity. So, based on the backdrop, as mentioned earlier, we'll now focus on implementing alternative winglet designs, generating parameters such as drag force and lift, and finally determining the most effective design based on the shape and flow regimes. Autodesk Fusion 360, Education License, the integrated CAD/CAM and 3D modeling software, is used to develop novel winglet designs. Ansys Fluent student version displays flow parameters, analysis, and simulations.Objectius de Desenvolupament Sostenible::9 - Indústria, Innovació i Infraestructur
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