Recursos de colección

Archivo Digital UPM (107.543 recursos)

This is an institutional repository providing access to the research output of the institution. Primarily contains thesis.

Materia = Aeronáutica

Mostrando recursos 1 - 20 de 1.060

  1. Non-cooperative target identification based on singular value decomposition

    Hernán Vega, Olga; López Rodríguez, Patricia; Escot Bocanegra, David; Fernández Recio, Raúl; Bravo Muñoz, Ignacio
    Non-Cooperative Target Identification based on High Resolution Range Profiles is a key research domain in the Defense industry. In this paper a method based on the application of Singular Value Decomposition to a matrix of range profiles is defined. The decomposition is applied to reduce dimensionality and to accomplish recognition in the transformed domain. So as to confirm the feasibility of the methodology, identification experiments of profiles coming from electromagnetic simulations are conducted, revealing promising results.

  2. Non-cooperative identification of civil aircraft using a generalised mutual subspace method

    López Rodríguez, Patricia; Escot Bocanegra, David; Fernández Recio, Raúl; Bravo Muñoz, Ignacio
    The subspace-based methods are effectively applied to classify sets of feature vectors by modelling them as subspaces. However, their application to the field of non-cooperative target identification of flying aircraft is barely seen in the literature. In these methods, setting the subspace dimensionality is always an issue. Here, it is demonstrated that a modified mutual subspace method, which uses softweights to set the importance of each subspace basis, is a promising classifier for identifying sets of range profiles coming from real in-flight targets with no need to set the subspace dimensionality in advance. The assembly of a recognition database is also...

  3. Virtual-work-based optimization design on compliant transmission mechanism for flapping-wing aerial vehicles

    Zhang, Chao; Rossi, Claudio; He, Wei; Colorado Montaño, Julián
    This paper presents a method for analyzing and optimizing the design of a compliant transmission mechanism for a flapping-wing aerial vehicle. Its purpose is of minimizing the peak input torque required from a driving motor. In order to maintain the stability of flight, minimizing the peak input torque is necessary. To this purpose, first, a pseudo-rigid-body model was built and a kinematic analysis of the model was carried out. Next, the aerodynamic torque generated by flapping wings was calculated. Then, the input torque required to keep the flight of the vehicle was solved by using the principle of virtual work....

  4. A Review of Macroscopic Motion in Thermodynamic Equilibrium

    Sanmartín Losada, Juan Ramón
    A principle on the macroscopic motion of systems in thermodynamic equilibrium, rarely discussed in texts, is reviewed: Very small but still macroscopic parts of a fully isolated system in thermal equilibrium move as if points of a rigid body, macroscopic energy being dissipated to increase internal energy, and increase entropy along. It appears particularly important in Space physics, when dissipation involves long-range fields at Electromagnetism and Gravitation, rather than short-range contact forces. It is shown how new physics, Special Relativity as regards Electromagnetism, first Newtonian theory then General Relativity as regards Gravitation, determine different dissipative processes involved in the approach...

  5. SIGS: Synthetic Imagery Generating Software for the development and evaluation of vision-based sense-and-avoid systems

    Carrió Fernández, Adrián; Changhong, Fu; Collumeau, Jean-Françoise; Campoy Cervera, Pascual
    Unmanned Aerial Systems (UASs) have recently become a versatile platform for many civilian applications including inspection, surveillance and mapping. Sense-and-Avoid systems are essential for the autonomous safe operation of these systems in non-segregated airspaces. Vision-based Sense-and-Avoid systems are preferred to other alternatives as their price, physical dimensions and weight are more suitable for small and medium-sized UASs, but obtaining real flight imagery of potential collision scenarios is hard and dangerous, which complicates the development of Vision-based detection and tracking algorithms. For this purpose, user-friendly software for synthetic imagery generation has been developed, allowing to blend user-defined flight imagery of a...

  6. Analysis of design alternatives on using dynamic and partial reconfiguration in a space application

    Veljković, Filip; Riesgo Alcaide, Teresa; Berrojo, Luis; Regada, Raúl; Álvaro Castellanos, Ángel de; Torre Arnanz, Eduardo de la
    Some of the biggest concerns in space systems are power consumption and reliability due to the limited power generated by the system's energy harvesters and the fact that once deployed, it is almost impossible to perform maintenance or repairs. Another consideration is that during deployment, the high exposure to electromagnetic radiation can cause single event damage effects including SEUs, SEFIs, SETs and others. In order to mitigate these problems inherent to the space environment, a system with dynamic and partial reconfiguration capabilities is proposed. This approach provide s the flexibility to reconfigure parts of the FPGA while still in operation,...

  7. Analysis of thermionic bare tether operation regimes in passive mode

    Sanmartín Losada, Juan Ramón; Chen, Xin; Sánchez Arriaga, Gonzalo
    A thermionic bare tether (TBT) is a long conductor coated with a low work-function material. In drag mode, a tether segment extending from anodic end A to a zero-bias point B, with the standard Orbital-motion-limited current collection, is followed by a complex cathodic segment. In general, as bias becomes more negative in moving from B to cathodic end C, one first finds space-chargelimited (SCL) emission covering up to some intermediate point B*, then full Richardson-Dushman (RD) emission reaching from B* to end C. An approximate analytical study, which combines the current and voltage profile equations with results from asymptotic studies of the Vlasov-Poisson system for emissive...

  8. New direct alcohol and hydrogen fuel cells for naval and aeronautical applications (PILCONAER)

    Aparicio Ambros, Mario; Mosa Ruiz, Jadra; Chinarro Martin, Eva; Moreno Burriel, Berta; Garcia Escribano, Maria Pilar; Rio Bueno, Carmen del; Morales Bergas, Enrique; Leo Mena, Teresa de Jesus; Carrillo Ramiro, Isabel; Mora Peña, Eleuterio; Navarro Arevalo, Emilio; Maellas Benito, Jesus; Gonzalez Lopez, Eduardo; Garcia Gonzalo, Carmen; Argumosa Martinez, Pilar; Raso García, Miguel Ángel
    In the current context of demand for reliable, low cost and low environmental impact energy sources, many countries and companies are mostly focused on fuel cells (FC) in fields as transportation and stationary power generation and portable devices. Lately, FCs have begun to be applied in naval and aeronautical systems due to its high efficiency, low noise and environmental advantages. These applications could range from propulsion systems to auxiliary power units(APU). The main problems associated with the use of FCs in these areas are the current high cost due to the materials used, i.e. Nafion and Pt, the lack of...

  9. Theoretical study of the energy harvesting of a cantilever with attached prism under aeroelastic galloping

    Xu-Xu, Ji; Vicente-Ludlam, David; Barrero Gil, Antonio
    The aeroelastic galloping of a cantilever with attached prism has recently attracted the attention of several researchers as a way to harvest energy from an airstream. This arrangement is not entirely analogous to that of classical Transverse Galloping (TG) since the instantaneous attitude of the galloping body (prism) with respect to the incident flow depends both on the velocity of the galloping body and wind speed (like in TG) but also on the rotation angle at the cantilever free end. A new governing parameter emerges, namely the ratio of the cross-section length of the prism to the beam length ?,...

  10. Assessment of experimental optical techniques for characterizing heat transfer using numerical simulations

    López Juste, Gregorio; Fajardo, P.
    This manuscript addresses the application of numerical simulations for assessing the error in the measurement of the bulk temperature along the laser beam of a 3D flow using a 2D Moiré deflectometry analysis. To analyze the effect of different flow parameters on the error, a 3D computational model of an experimental system was developed. The simulated domain represents the well-known solution of the backward facing step in a rectangular channel but includes a hot-plate at the bottom of the step to enhance the heat transfer effects. The geometry resembles that found in a general heat exchanger. The difference between the...

  11. Medida del deterioro del hormigón sometido a hielo-deshielo con bandas extensométricas

    Romero, Hector; Casati Calzada, Maria Jesus; Galvez Ruiz, Jaime Carlos
    Los daños producidos por los ciclos de hielo deshielo en el hormigón llegan hasta un 13% del total de los daños. Estos daños pueden ser internos y externos, y se manifiestan en la disminución del módulo de elasticidad dinámico y la aparición de fisuras, y el descascarillamiento superficial, respectivamente. La mayoría de los ensayos normalizados para la evaluación de la resistencia del hormigón a los efectos del H-D se basan en la medida del daño externo. Estas medidas requieren parar el ensayo y manipular las probetas fuera de la cámara climática. En este trabajo se propone el uso de medidas...

  12. Docencia presencial y laboratorio remoto: una unión idónea para las prácticas de motores alternativos

    Tizón Pulido, Juan Manuel; Navarro Arevalo, Emilio
    Se ha utilizado en una misma clase presencial recursos docentes convencionales, como son la clase magistral y las presentaciones en pantalla, junto con un laboratorio remoto para impartir docencia de prácticas de laboratorio de Motores Alternativos de Combustión Interna. En ambos casos se ha hecho uso de cámaras de video para visualizar las instalaciones en tiempo real. La clase magistral se ha utilizado para describir las instalaciones que forman parte de un banco de ensayos y el laboratorio remoto se ha utilizado para realizar ensayos para la determinación de actuaciones de un motor de encendido provocado. Con esta metodología se...

  13. Aerodynamic shape optimization of a 3D wing via volumetric B-Splines

    Martín Burgos, Mario Jaime; Andrés Pérez, Esther; Gomez Lopez, Mariola
    This paper shows a gradient-based aerodynamic shape optimization of a threedimensional wing using volumetric B-Splines. The wing is enclosed in a volumetric parallelepiped, commonly referred as control box, which can be seen as a rubber box that deforms the enclosed space. The deformation of the wing is provided by the manipulation of the control points, where the gradients are calculated using the continuous adjoint solution. This technique can be applied to arbitrary three dimensional complex designs and provides some advantages over other traditional geometry parameterization methods, such as deformation locality and the ability to handle some geometric constraints.

  14. A singularity-free DROMO-based regularized method for the propagation of roto-translationally coupled asteroids

    Urrutxua Cereijo, Hodei; Pelaez Alvarez, Jesus
    There are many asteroids for which the attitude coupling imposes harsh demands to the numerical propagation of their dynamics. Special regularization methods are appropriate to overcome such difficulties, where perturbations techniques make their best. The perturbation techniques used to derive the DROMO regularization method for orbital dynamics, have now been extended to the attitude dynamics problem with equally remarkable results both in terms of speed and accuracy. The combination of these DROMO-based techniques is thus appropriate for the propagation of strongly coupled bodies.

  15. Mesh movement strategy based on octree decomposition

    Gómez López, Mariola; Cordero Gracia, Marta Amalia; Ponsin Roca, Jorge; Valero Sánchez, Eusebio
    The aim of the present work is to apply an interpolation method based on Radial Basis Functions(RBF) to transfer deformations from surface mesh to volume mesh in multidisciplinary CFD computations. In order to deal with the increasing need in all engineering areas to manipulate meshes of very large computational size, it is mandatory to develop methodologies based on the decomposition of the global problem into local smaller problems according to the current computational capabilities of personal computers. In this way we have applied an octree decomposition to generate computational domains where the interpolation can be easily affordable. The problem now...

  16. An interpolation tool for aeroelastic data transfer problems

    Cordero Gracia, Marta Amalia; Gomez Lopez, Mariola; Valero Sanchez, Eusebio
    In the loosely-coupled aeroelastic methodology, the aerodynamic and structural models are computed on different meshes. CFD tools are applied over the aerodynamic grid whereas CSM tools over the structural one. Depending on the model, the meshes can or not share an interface. In stick models, for example, there is no real interface. A common problem consists on transfering structural deformations to the aerodynamic mesh and aerodynamic loads to the structural one. In this work we have developed an interpolation tool based on Radial Basis Functions (RBF) to transfer information between loosely-coupled meshes, independent of their topologies. The problem arises when...

  17. Definición e integración de procedimientos de descenso continuo para la mitigación de ruido en la operación del TMA y del Aeropuerto de Madrid - Barajas

    Arnaldo Valdes, Rosa Maria; Gomez Comendador, Víctor Fernando; Perez Sanz, Luis
    Aplicación operativa de procedimientos de vuelo de aeronaves de mitigación de ruido, con minimización del impacto sobre la capacidad

  18. Investigación de accidentes RPAS

    Arnaldo Valdes, Rosa Maria
    Taller para la Comunidad Española de RPAS Grupo 6 - Aspectos de educación y genéricos de seguridad de la integración de los RPAS

  19. Estudio de la maquinabilidad de aleaciones de aluminio-cobre

    Sánchez Almirón, Borja; Aguirre Cebrian, Maria Vega; Calvo Narvaez, Felix; González Requena, Ignacio; Sanz Lobera, Alfredo
    El cometido principal es establecer una metodología para analizar y evaluar la maquinabilidad de una aleación aluminio-cobre mecanizada en torno utilizando los recursos disponibles en los laboratorios de materiales y producción. El estudio se realizó mediante la medida del caudal de viruta, el dimensionado de la herramienta durante el proceso y su análisis microscópico. También se estudió el posible desgaste de la herramienta y qué factores han podido incrementar o disminuir dicho valor. Se han mecanizado ocho barras de una aleación 2030 T4 con dos herramientas de corte idénticas de carburo de wolframio. Esto permite usar cada filo de corte...

  20. Plasma simulation in space propulsion : the helicon plasma thruster

    Navarro Cavallé, Jaume
    The Helicon Plasma Thruster (HPT) is an electrodynamic rocket proposed in the early 2000s. It matches an Helicon Plasma Source (HPS), which ionizes the neutral gas and heats up the plasma, with aMagneticNozzle (MN),where the plasma is supersonically accelerated resulting in thrust. Although the core of this thruster inherits the knowledge on Helicon Plasma sources, dated from the seventies, the HPT technology is still not developed and remains below TRL 4. A deep review of the HPT State-of-art has been performed, concluding that the propulsive figures reached for some prototypes abruptly differ from each other. This Thesis analyses some of...

Aviso de cookies: Usamos cookies propias y de terceros para mejorar nuestros servicios, para análisis estadístico y para mostrarle publicidad. Si continua navegando consideramos que acepta su uso en los términos establecidos en la Política de cookies.