Search results for "IRP"

SCELTA E APPLICAZIONE DI NUOVI STANDARD DI MANOVRA NELLE FASI DI DECOLLO ED ATTERRAGGIO DELL’ELICOTTERO - MODELLO E SPERIMENTAZIONE -

Una zona o un ambiente ha tipicamente un livello sonoro che lo caratterizza e ci si aspetta che le variazioni di quell’ambiente in equilibrio dovute ad un evento acustico insolito alterino le sensazioni delle persone in quel contesto. Non ci si può riferire al buon senso per valutare se disturbiamo o danneggiamo il prossimo, è necessario individuare le fonti di rumore e valutare l’impatto ambientale tramite indagini di tipo qualitativo e fasi sperimentali di misura. Lo studio condotto ha correlato il dato qualitativo a quello quantitativo sia in ambito predittivo che tramite rilievi sul campo. Gli scopi e gli obiettivi sono incentrati a: ricercare una simulazione coerente di propagazione de…

Asphalt mixtures improved with plastic additives: mix design and case study in an airport

La crescente domanda di prestazioni e le esigenze di salvaguardia dell’ecosistema spingono a sviluppare nuove tecnologie di lavorazione, a sperimentare l’impiego di nuovi materiali, a migliorare i metodi di progetto delle miscele. Il criterio seguito è quello di un impiego più razionale delle risorse e dell’utilizzo di tecniche a basso impatto ambientale. Per ragioni tecniche ed economiche stiamo assistendo al fenomeno di espansione nel mercato degli additivi, impiegati nella produzione di miscele bituminose per migliorarne le prestazioni e ridurre i costi. In generale, però riuscire a soddisfare tutti gli obiettivi con un unico prodotto è difficile, perché l’alta qualità richiede costi più…

Airport Charges Policy as a Tool for Achieving Competitive Advantage in the Aviation Market

2020

Air transportation plays an important socio-economic role, and an airport, as part of the transportation system, is a significant component of the national infrastructure. The airport is not just a provider of aviation services, whose activities are regulated by the state, but is a self-sustainable commercial complex with its own business goals and development strategy aimed at the growth and economic efficiency of operations. Strengthening its position in the Nordic region is the strategic goal of Riga International Airport. Competitive advantage in airport charges policy should contribute to the accomplishment of this strategic goal - Riga Airport should be the first choice for airport tr…

Asymmetries in the momentum distributions of electrons stripped by a XUV chirped pulse in the presence of a laser field

2012

The ionization of hydrogen by a chirped XUV pulse in the presence of a few cycle infrared laser pulse has been investigated. The electron momentum distribution has been obtained by treating the interaction of the atom with the XUV radiation at the first order of the time-dependent perturbation theory and describing the emitted electron through the Coulomb-Volkov wavefunction. The results of the calculations agree with the ones found by solving numerically the time-dependent Schr¨odinger equation. It has been found that depending on the delay between the pulses the combined effect of the XUV chirp and of the steering action on the infrared field brings about asymmetries in the electron momen…

A study of noise transmission through cylindrical shell using modal truncation approach

2011

International audience; The study of the vibroacoustic behaviour of cylindrical structure like aircraft fuselage requires the establishment of very large models, and the numerical results which can be obtained are often difficult to interpret. On the other hand, the study of simple structures such as cylindrical shells is useful to validate the criteria and tools that can be used to simplify the models of complex structures. The presented study concerns the sound transmission through a cylindrical shell coupled to a cavity and subjected to an incident acoustic wave. Noise reduction is obtained and validated by a numerical method which uses structural and acoustical modes. A criterion for se…

Synchronization techniques for power quality instruments

2004

The measurement of voltage characteristics in power systems requires the accurate estimation of the power supply frequency and signal synchronization, even in the presence of disturbances. The authors developed and tested two innovative techniques for instrument synchronization. The first is based on signal spectral analysis techniques performed by means of the Chirp-Z transform analysis. The second is a phase-locked loop (PLL) software based on a time-domain coordinate transformation and an innovative phase-detection technique. To evaluate how synchronization techniques are adversely affected by the application of a disturbing influence, experimental tests were carried out, taking into acc…

Towards more sustainable airfield pavements using life-cycle assessment of design alternatives

2020

Airports are critical infrastructures and their success is paramount to development through tourism, trade and connectivity. Within the airport, the runway pavement must always be in a pristine condition. Consequently, pavement design and maintenance decisions are vital. Authorities must make decisions concerning preferred materials for design and maintenance. Decisions should be balanced by both economic and environmental factors. This paper considers a case study at Falcone Borsellino Airport (PMO), Palermo, Italy, where air traffic has been steadily increasing. Different pavements are proposed: flexible Asphaltic concrete designs with both traditional Asphaltic concrete and using reclaim…

An induction motor speed measurement based on current harmonic analysis with Chirp-Z Transform

2002

The paper presents a new method to measure motor speed by means of frequency estimation of rotor slot harmonics present in the supply current of squirrel single cage induction motors. The novelty of the method is the use of Chirp-Z Transform as supply current harmonic analysis. The advantages are an improved spectral resolution and accuracy. Moreover a shorter sampling time window is required reducing errors related to not stationary current signal. Experimental results are presented to validate the proposed method and to perform a comparison with FFT based one.

Different Wings Flowfields Interaction on the Wing-Propeller Coupling

1997

A high-portability numerical technique based on the method of free wake analysis (FWA) is described that analyzes the interference between an aircraft propeller and a wing having different planforms and computes the influence of the wing aerodynamic field on the propeller performance. For an isolated propeller and wing, the models employed are based on the FWA and Prandtl theory, respectively. The performance of the propeller in the presence of the wing is related to the wing angle of attack and to the variation of wing circulation and the corresponding induced velocity at the propeller disk. A numerical model, previously and successfully used, was implemented to account for the effects of …

A pedagogical flight simulator for longitudinal airplane flight

2009

This article presents a bi-dimensional model of flight and describes the implementation of a flight simulator able to describe the different phases of longitudinal flight of a real airplane. After identifying the relevant physical variables, the equations of motion are written and solved using a numerical integration method. Using computer simulations, flight paths and time evolution of the kinematics variables are analyzed for a complete flight of a light commercial airplane. The simulations take into account and reproduce the basic actions of a pilot to control the flight. The main maneuvers involved in pilotage are also predicted and explained in terms of model parameter variations induc…