Search results for "Aerospace Engineering"

Monte Carlo study of an imager for low-energy γ-ray astronomy: Optimization of the design and evaluation of the scientific performances

1997

Abstract In this paper we present the phase A studies which were carried out for the optimization of the design and evaluation of the scientific performances of the Imager, which is one of the two main instruments under development for the INTEGRAL mission, selected by ESA as the next scientific mission of medium size (M2). These studies were done by Monte Carlo simulation, using the CERN GEANT-3 package. Both the whole geometry and materials defining the Imager were considered in the simulations.

An experiment on wind energy

2012

We discuss an experiment on wind energy performed with home-made apparatus. The experiment reproduces a laboratory windmill, which can pump water from a lower level to a higher one. By measuring the gain of the gravitational potential energy of the pumped water, one can determine the power extracted from the wind. The activity was carried out with high-school students, in the framework of the Italian National Plan for Scientific Degrees-Physics. The proposed experiment allows teachers to discuss renewable energy sources with students whose knowledge of physics is limited to mechanics. It gives students the possibility to gain experience with energy and to increase their awareness of this re…

ZERO-DIMENSIONAL UNSTEADY INTERNAL BALLISTIC MODELING

2002

Correlation and Spectral Properties of Vehicle-to-Vehicle Channels in the Presence of Moving Scatterers

2013

This paper derives a vehicle-to-vehicle (V2V) channel model assuming a typical propagation scenario in which the local scatterers move with random velocities in random directions. The complex channel gain of the proposed V2V channel model is provided. Subsequently, for different scatterer velocity distributions, the corresponding autocorrelation function (ACF), power spectral density (PSD), and the Doppler spread of the channel are derived, shown, and confirmed by the available measurement data. It is shown that the Gaussian mixture (GM) and the exponential distribution can accurately describe the velocity distribution of relatively fast and slow moving scatterers, respectively. Since the p…

The Palermo XACT facility: a new 35 m long soft x-ray beam-line for the development and calibration of next-generation x-ray observatories

2006

The X-ray Astronomy Calibration and Testing (XACT) facility of the Instituto Nazionale di Astrofisica (INAF) at Osservatorio Astronomico di Palermo has recently undergone a major upgrade with the design and construction of a 35 meter long vacuum beam-line operating in the soft X-rays (0.1-20 keV) and the addition of new hardware to meet the requirements for testing and calibration of next generation X-ray missions. We report on the present configuration of the facility and briefly survey the range of its applications.

Modeling hydrodynamic interactions in soft materials with multiparticle collision dynamics

2019

Multiparticle collision dynamics (MPCD) is a flexible and robust mesoscale computational technique for simulating solvent-mediated hydrodynamic interactions in soft materials. Here, we provide a critical overview of the MPCD method and summarize its current strengths and limitations. The capabilities of the method are highlighted by reviewing its recent applications to simulate diverse phenomena, ranging from the flow of complex fluids and thermo-osmotic transport to bacterial swimming and active particle self-assembly. We also discuss outstanding challenges and emerging methodological developments that are expected to greatly expand the applicability of MPCD to other systems of technologic…

Video-Analysis of the flight of a model aircraft

2011

A video-analysis software tool has been employed in order to measure the steady-state values of the kinematics variables describing the longitudinal behaviour of a radio-controlled model aircraft during take-off, climbing and gliding. These experimental results have been compared with the theoretical steady-state configurations predicted by the phugoid model for longitudinal flight. A comparison with the parameters and performance of the full-size aircraft has also been outlined.

E-sail test payload of the ESTCube-1 nanosatellite

2014

The scientific mission of ESTCube-1, launched in May 2013, is to measure the electric solar wind sail (E-sail) force in orbit. The experiment is planned to push forward the development of the E-sail, a propulsion method recently invented at the Finnish Meteorological Institute. The E-sail is based on extracting momentum from the solar wind plasma flow by using long thin electrically charged tethers. ESTCube-1 is equipped with one such tether, together with hardware capable of deploying and charging it. At the orbital altitude of ESTCube-1 (660–680 km) there is no solar wind present. Instead, ESTCube-1 shall observe the interaction between the charged tether and the ionospheric plasma. The E…

Development of a low-cost piezo film-based knock sensor

2003

It is well known that spark advance is a key parameter in spark ignition engine management. Increasing fuel cost and emission regulation strictness require a higher engine efficiency, which can be improved by an accurate regulation of the spark advance. Under high load conditions, an optimal spark advance choice leads the engine to run next to the knock limit, so the management and control system needs to be equipped with a knock sensor in order to preserve the engine from damage. The authors developed a low-cost knock sensor whose sensing element is a thin washer of polyvinylidine fluoride (PVDF), a fluoropolymer characterized by a great piezoelectric e ect if polarized. The sensor has be…

Mhd-Modeling of the Propagation of a Coronal Mass Ejection

2005

Hydrodynamic modeling of the propagation of a density perturbation launched upwards in the solar corona has been shown to explain some features of a Coronal Mass Ejection (CME) observed in detail with the SoHO/UVCS, but left open the questions of the evidence of thermal insulation of the CME and of its large expansion factor. We investigate whether the interaction with the coronal magnetic field is able to explain these aspects, by performing magnetohydrodynamic simulations. We solve the ideal MHD equations for a fully ionized compressible plasma with different assumptions on the ambient magnetic field, using the FLASH code. We include the effect of the directional thermal conduction. Preli…