1,081 research outputs found
Design of a Three Surfaces R/C Aircraft Model
Design of a three lifting surfaces radio-controlled model has been carried out at Dipartimento di Progettazione Aeronautica (DPA) by the authors in the last year. The model is intended to be a UAV prototype and is now under construction. The main goal of this small aircraft's design is to check the influence of the canard surface on the aircraft's aerodynamic characteristics and flight behavior, especially at high angles of attack. The aircraft model is also intended to be a flying platform to test sensors, measurement and acquisition systems for research purposes and a valid and low-cost teaching instrument for flight dynamics and flight maneuvering. The aircraft has been designed to fly with and without canard, and all problems relative to aircraft balance and stability have been carefully analyzed and solved. The innovative configuration and the mixed wooden-composite material structure has been obtained with very simple shapes and all the design is focused on realizing a low-cost model. A complete aerodynamic analysis of the configuration up to high angles of attack and a preliminary aircraft stability and performance prediction will be presented
Design of a Three Surfaces R/C Aircraft Model
Design of a three lifting surfaces radio-controlled model has been carried out at Dipartimento di Progettazione Aeronautica (DPA) by the authors in the last year. The model is intended to be a UAV prototype and is now under construction. The main goal of this small aircraft's design is to check the influence of the canard surface on the aircraft's aerodynamic characteristics and flight behavior, especially at high angles of attack. The aircraft model is also intended to be a flying platform to test sensors, measurement and acquisition systems for research purposes and a valid and low-cost teaching instrument for flight dynamics and flight maneuvering. The aircraft has been designed to fly with and without canard, and all problems relative to aircraft balance and stability have been carefully analyzed and solved. The innovative configuration and the mixed wooden-composite material structure has been obtained with very simple shapes and all the design is focused on realizing a low-cost model. A complete aerodynamic analysis of the configuration up to high angles of attack and a preliminary aircraft stability and performance prediction will be presented
Flight Tests, Performances and Flight Certification of a Twin-Engine Light Aircraft
This paper deals with flight test activities performed on P2006T, a twin-engine light aircraft recently designed and produced by Tecnam. Research activities and flight tests have been conducted during the flight certification of P2006T for the normal category under CS-23. All the acquired data and flight results presented have been focused on both aircraft certification and on aircraft performances, stability and flight qualities measurement. The data have been acquired through a light, accurate and reliable flight instrumentation available at DIAS (Department of Aerospace Engineering). Some flight data about aircraft leveled speed, stall speed, climb characteristics and ground performances (take-off and landing) will be presented. After preliminary flight tests, winglets have been designed and added to the final configuration in order to obtain good climb performances also in OEI (One Engine Inoperative) conditions. Accurate stall tests have been performed in all configurations and influence of both entry-rate and load factor on stall speed have been highlighted. Excellent ground performances have been measured with short take-off and landing distances compared with similar airplanes. All measured flight performances can be considered very good for this aircraft category and have been used to demonstrate aircraft safety and to obtain CS23 certification
Tracking ground state Ba+ ions in an expanding laserâplasma plume using time-resolved vacuum ultraviolet photoionization imaging
We report results from a study of the integrated column density and expansion dynamics of ground-state-selected Ba+ ions in a laserâplasma plume using a new experimental systemâVPIF (vacuum-ultraviolet photoabsorption imaging facility). The ions are tracked by recording the attenuation of a pulsed and collimated vacuum ultraviolet beam, tuned to the 5pâ6d inner-shell resonance of singly ionized barium, as the expanding plasma plume moves across it. The attenuated beam is allowed to fall on a CCD array where the spatial distribution of the absorption is recorded. Time-resolved ion velocity and integrated column density maps are readily extracted from the photoionization images
Swept source optical coherence tomography findings in a severe traumatic maculopathy following firework ocular injury
A probabilistic approach to the evaluation of seismic resilience in road asset management
Road networks are classified as critical infrastructure systems. Their loss of functionality not only hinders residential and commercial activities, but also compromises evacuation and rescue after disasters. Dealing with risks to key strategic objectives is not new to asset management, and risk management is considered one of the core elements of asset management. Risk analysis has recently focused on understanding and designing strategies for resilience, especially in the case of seismic events that present a significant hazard to highway transportation networks. Following a review of risk and resilience concepts and metrics, an innovative methodology to stochastically assess the economic resources needed to restore damaged infrastructures, one that is a relevant and complementary element within a wider resilience-based framework, is proposed. The original methodology is based on collecting and analyzing ex post reconstruction and hazard data and was calibrated on data measured during the earthquake that struck central Italy in 2016 and collected in the following recovery phase. Although further improvements are needed, the proposed approach can be used effectively by road managers to provide useful information in developing seismic retrofitting plans
An EpiDoc ontological perspective: the epigraphs of the Castello Ursino Civic Museum of Catania via CIDOC CRM
The rich epigraphic heritage of the Castello Ursino Civic Museum of Catania has been studied by the EpiCUM project that encoded it in EpiDoc TEI XML, an XML based standard digital representation for cultural heritage contents. The project made the epigraphic heritage available in a digital museum: under the guise of the âVoci di Pietraâ exhibition, a selection of epigraphs were presented, implementing innovative presentation modalities thanks to a smart use of technological and digital means. Information contained in the epigraphs was semantically reorganized in a unique homogeneous container, the EpiONT ontology, constructed according to the Linked Open Data paradigm and to consolidated international standards. The encoding of the ancient texts, by the TEI standard and its EpiDoc subset, is wedded to the paradigmatic semantic web model for museums and cultural heritage. The EpiONT ontology is currently populated by 580 epigraphs collected in the Castello Ursino Civic Museum. Designed according to the CIDOC CRM standard, it makes use of the SKOS vocabularies of the EAGLE project concerning material, execution technique, type of inscription, and type of support of an epigraph. The EpiONT ontology additionally can handle any uncertainty in the origin and place of discovery of the epigraphs
Dynamic Behaviour of the Patented Kobold Tidal Current Turbine: Numerical and Experimental Aspects
This paper provides a summary of the work done at DPA on numerical and experimental investigations of a novel patented vertical axis and variable pitching blades hydro turbine designed to harness energy from marine tidal currents. Ponte di Archimede S.p.A. Company, located in Messina, Italy, owns the patented KOBOLD turbine that is moored in the Messina Strait, between the mainland and Sicily. The turbine has a rotor with a diameter of 6 meters, three vertical blades of 5 meters span with a 0.4 m chord ad hoc designed curved airfoil, producing high lift with no cavitation. The rated power is 160 kW with 3.5 m/s current speed, which means 25% global system efficiency. The VAWT and VAWT_DYN computer codes, based on Double Multiple Steamtube, have been developed to predict the steady and dynamic performances of a cycloturbine with fixed or self-acting variable pitch straight-blades. A theoretical analysis and a numerical prediction of the turbine performances as well as experimental test results on both a model and the real scale turbine will be presented and discussed.
End-to-End System Test and Optical Performance Evaluation for the Solar and Heliosphere Observatory (SOHO) Ultraviolet Coronagraph Spectrometer (UVCS)
The UVCS is one of the instruments carried by the Solar and Heliospheric Observatory (SOHO), a joint NASA/ESA Spacecraft launched in November 1995. It is designed to perform ultraviolet spectroscopy and visible light polarimetry of the extended solar corona. The primary scientific objectives of the UVCS investigation are to study the physical processes occurring in the extended solar corona, such as: the mechanism of acceleration of the solar wind, the mechanism of coronal plasma heating, the identification of solar wind sources, and the investigation of the plasma properties of the solar wind. The UVCS End-to-End test activities included a comprehensive set of system level functional and optical tests. Although performed under severe schedule constraints, the End-to-End System Test was very successful and served to fully validate the UVCS optical design. All test results showed that the primary scientific objectives of the UVCS Mission were achievable
Comparing extrapolations of the coronal magnetic field structure at 2.5 solar radii with multi-viewpoint coronagraphic observations
The magnetic field shapes the structure of the solar corona but we still know
little about the interrelationships between the coronal magnetic field
configurations and the resulting quasi-stationary structures observed in
coronagraphic images (as streamers, plumes, coronal holes). One way to obtain
information on the large-scale structure of the coronal magnetic field is to
extrapolate it from photospheric data and compare the results with
coronagraphic images. Our aim is to verify if this comparison can be a fast
method to check systematically the reliability of the many methods available to
reconstruct the coronal magnetic field. Coronal fields are usually extrapolated
from photospheric measurements typically in a region close to the central
meridian on the solar disk and then compared with coronagraphic images at the
limbs, acquired at least 7 days before or after to account for solar rotation,
implicitly assuming that no significant changes occurred in the corona during
that period. In this work, we combine images from three coronagraphs
(SOHO/LASCO-C2 and the two STEREO/SECCHI-COR1) observing the Sun from different
viewing angles to build Carrington maps covering the entire corona to reduce
the effect of temporal evolution to ~ 5 days. We then compare the position of
the observed streamers in these Carrington maps with that of the neutral lines
obtained from four different magnetic field extrapolations, to evaluate the
performances of the latter in the solar corona. Our results show that the
location of coronal streamers can provide important indications to discriminate
between different magnetic field extrapolations.Comment: Accepted by A&A the 20th of May, 201
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