Preliminary study and experimental test of Peltier cells for a potential implementation in a renewable energy device

The present work focuses its attention about the need of implementation of a cooling system for photovoltaic cells. In fact the efficiency and technical lifetime is strongly affected by temperature of photovoltaic cell and this is a fundamental topic for every installation but above all in the cases of regions with a very hot climate or for concentrated photovoltaic plants. In a specific way it is proposed preliminary evaluations and study for a potential use of a thermoelectric cooling system for PV, based on Peltier cells. An overview of Peltier cells, treating about their functionality, properties and possible applications, is presented. It is performed an experimental phase, which is based on the creation of the setup and preliminary tests on Peltier cells for the next implementation in a cooling system for PV cells

STRUCTURAL DYNAMIC CHARACTERIZATION OF A PLATE TYPE ELEMENT ORIENTED AT ACTIVE CONTROL IMPLEMENTATION

Successful implementation of an active vibration control system is strictly correlated to the exact knowledge of the dynamic behavior of the the system, of the excitation level and spectra and of the sensor and actuator’s specification. Only the correct management of these aspects may guarantee the correct choice of the control strategy and the relative performance. Within this paper, some preliminary activities aimed at the numerical and experimental dynamic characterization of a plate type test article as well as the evaluation of piezoelectric sensors and actuators will be presented and discussed. All these information represent, in-fact, the basic information for a successive choice and implementation of the more appropriate active control strategy

ACOUSTIC IMPACT OF CAPODICHINO AIRPORT BY THE USE OF THE AEDT SOFTWARE

About the study of the acoustic impact of the Capodichino airport (Naples), a new acoustic simulation soft ware was used to generate the study of noise propagation in the area near the airport and relative footprint. In the past, the INM (Integrated Noise Model) calculation code provided by the FAA (Federal Aviation Agency) has been represented the standard code for these simulation operations and widely used all over the international airports. Anyway, in the last three years, a new code has been implemented by the FAA, to overcome some of the lim itation of the INM. This new tool, named Aviation Environmental Design Tool (AEDT) present a new manage ment of the acoustic parameters (as, for instances the implementation of innovative sound absorption model such as the SAE-AIR-5534) and a different management of the acoustic maps definition (as, for instances, the use of dynamic grids) . It also allow to a contextual management of acoustic and air pollution (CO2) problems. AEDT also presents a catalog of aircraft updated and constantly updated, which INM did not have and for which equivalent aircraft should have been taken. In the framework of the present study, AEDT provisional results have been compared with data already available and based upon the use of the INM code. An in-depth study has been also dedicated to the comparison of numerical forecasted data and experimental one measured at specific target point through the use of the Capodichino Airport remote monitoring noise sys tem. The study has highlighted some of the peculiarities of the new software consolidating the opportunity to use AEDT as future planning tool for Capodichino and other airport’s scenario

Numerical Simulation For ANN Training and validation For Impact Detection

Composite structures, today, have a relevant role in our life. The most of the object we use daily are done of composite materials. The recent increase in use of composite materials can be explained if we consider: * They have great strength; * They have low weight; The combination of these two characteristics is the main reason the composite materials are so appreciate in engineering. Every time we need to produce a light structure with high strength composite materials are the good approach to design it. Instead of benefits, composite materials have also some issues. From a structural point of view the most critical is the difficult to monitoring them. Metal materials integrity is easy to check, the most of the time a visual inspection is enough to detect failures also in early stage. In composite materials, due the way they are maiden, often is impossible detect failures until it is too late to repair them. The most common problem composite materials have is the delamination. It consists in a detachment of plys inside the material due to an impact on the material itself. From an exterior point of view it is impossible to detect by eye. It suddenly propagates inside the structure inducing failures. The task of this work is to develop an artificial neural network (ANN) able to detect impacts and restrict the part of structure to monitor looking for damages. I

Simulation and experimental validation of fatigue endurance limit of copper alloy for industrial application

Fatigue resistance performance represents one of the main characteristic for flexible structures as those used in aerospace and other means of transport. For this reason, particular attentions are dedicated during the design stage to the evaluation of the lifetime resistance parameters. Many numerical and analytical approaches are actually available for this purpose, as well-standardized experimental test procedures have been assessed. With reference to a copper bar of an electric motor, the paper presents a survey of the main analytical and numerical methodologies for the prediction of the fatigue peculiarities. The estimation data have been than validated by an experimental campaign in simulated operating conditions, revealing advantage and drawbacks of different models

Wheel – Rail interaction based on roughness calculation

Rolling noise is a relevant source in railway applications. The rolling noise is generated by the contact force the wheel, and the rail, exchange each other during relative motion. The interaction force between wheel and rail is generated by their roughness. Wheel and rail surfaces are not perfectly flat, they have a lot of small micro imperfections due to usage, damages, manufacturing. The whole of these imperfection is the roughness of the two surfaces. In the following a new interaction model will be shown where the roughness in kept in account to simulate the real case application. The model, based on previously studies, is improved introducing the rail and wheel real roughness for interaction force calculation. A real case study will be kept in account for model application and its application

Sound proofing and thermal properties of an innovative viscoelastic treatment for the turboprop aircraft fuselage

Low-resilience polyurethane foams including several additive constituents were synthesized to improve their vibro-acoustic performances, as well as the thermal insulation. viscoelastic polymer additive can attenuate vibrations and absorb sound energy. the vibro-acoustic properties of two innovative viscoelastic treatments fabricated with polyurethane foams are discussed in this paper using a typical aeronautical panel test setup. Since an aircraft insulation arrangement must provide both noise and thermal insulation for the specified operating conditions and expected thermal comfort of passengers, the thermal conductivity of the samples has been examined assuming a testing range between 20 °C (room temperature) and − 40 °C (cruise altitude). the results highlighted an optimal behavior of the novel viscoelastic foams in terms of both acoustic and thermal performance, offering a very interesting self-embedded solution with a good weight to performance ratio, compared to standard blanket composed by extra viscoelastic treatments

Development of a dynamic tool for aircraft noise reproduction

The aircraft is surely one of the most considerable invention that changed the transport-engineering field, since flying was already an ancient dream come true just a few years ago. Now it is really easy to reach many far places even if most people have no clue how flying is possible. However, as factories do, these large and faster and faster machines return a consistent amount of pollution every day. During take-off, engines reach the highest RPMs returning the most noise possible, and during landing, mobile surfaces produce a lot of aerodynamic disturbs releasing energy in the air while landing gears constantly produce drag in both circumstances. The need to be able to predict the sound emission of an acoustic source represents an extremely current engineering challenge: in particular, a numerical code that would let the user to listen noise produced by a flyover, since acoustic reports are just numerical statistics and spectrogram plots. In this paper, a numerical formulation is suggested for the prediction of the acoustic emission in the frequency domain. The main task of the project was to develop a program that makes dynamic analysis of the signal taking into account the source movement. Moreover, the simulations predicted the noise levels, thus explicitly accounting for the scattering acoustic effects of incidence and geometrical obstacles as well. Geometrical reflections and absorptions of certain frequencies depending on the material have been comprised in the model

Strain State Detection in Composite Structures: Review and New Challenges

Developing an advanced monitoring system for strain measurements on structural components represents a significant task, both in relation to testing of in-service parameters and early identification of structural problems. This paper aims to provide a state-of-the-art review on strain detection techniques in composite structures. The review represented a good opportunity for direct comparison of different novel strain measurement techniques. Fibers Bragg grating (FBG) was discussed as well as non-contact techniques together with semiconductor strain gauges (SGs), specifically infrared (IR) thermography and the digital image correlation (DIC) applied in order to detect strain and failure growth during the tests. The challenges of the research community are finally discussed by opening the current scenario to new objectives and industrial applications