SILVESTRI P.

The dynamic interaction between a flexible rail line and a traveling wheel can be treated in the framework of dynamic substructuring, assembling line and wheel through a moving contact point. The rail line is idealized as a continuous beam supported by the sleepers. It is discretized by the finite element method assuming the displacement and...

The paper summarizes the main aspects of an experimental vibro-acoustic investigation developed by the authors on two violas da gamba (named in the following as viols). The considered instruments show similar aesthetic and geometric characteristics, as one of them was made later adopting the other as a reference. However, they are characterized...

High operational vibrations in ships can lead to discomfort for passengers and crew and cause structural fatigue and cracking. Reducing these vibration levels under working conditions requires an understanding of both the characteristics of the excitation sources and the vibrational structural dynamic behaviour of the system in question. For...

The paper presents and discusses modelling and simulation of a robotic vehicle called FURBOT, designed for last mile delivery of freights. The focus is on the design process through simulation to meet requirements typical of a robot as well as automotive performance as for a commercial van. It is introduced the original concept of vehicle...

The use of centrifugal compressors has been increasing tremendously in the last decade as they are a key component in the present energy scenario both in the modern internal combustion engine design and in advanced cycles and innovative plant layouts as fuel cell systems. Instability phenomena limit the operating range of the whole compressor...

This paper presents an experimental investigation carried out on a large pleasure yacht during a sea trial using vibration signal processing methods to characterize its dynamic operational behaviour and to identify contributions of the main sources acting on the system including the onset of the propeller cavitation phenomenon. Synchronous...

There are several small energy sources that can be exploited to provide useful energy: small temperature differences, mechanical vibrations, flow variations, latent exhausts are just some examples. The recovery of such common and small energy sources, usually wasted, for example with the conversion into useful amounts of electrical energy, is...

Acoustic insulation optimization of the ship decks to contain impact noise is generally obtained by adopting suitable types of viscoelastic resilient materials. For this purpose, it is necessary to be able to make a correct choice of material. This is obtained by experimentally identifying the vibro-acoustic behavior of the combined...

Nowadays, turbocharging is a technique widely used to improve fuel consumption and exhaust emissions in automotive engines. Centrifugal compressors are typically adopted, even if an efficient engine integration is often restricted by surge phenomena. The focus of the present work is to describe an experimental analysis developed with the aim at...

The aim of this work is to describe the design and the use of an innovative test rig for investigating the expansion of subcooled fluids inside a converging nozzle and the evolution of two-phase flows in Tesla-type turbines. The flow exiting the nozzle enters tangentially into a thin flat circular chamber and it finally is discharged in the...

This paper focuses on rotor dynamic investigation of a bladeless turbine, or Tesla turbine, for application to innovative small scale cycles. Tesla rotor consists of a shaft with several co-rotating disks with small gaps between each other. The flow through the disks creates a momentum exchange by viscous effect, motoring the shaft. Thanks to...

The closing sound of a car door is objectively not related to the intrinsic quality of the vehicle but it is an important subjective parameter for vehicle evaluation. For automotive developers, it is very interesting to deepen this phenomenon and to define a methodology to understand the influence of several parameters on door-closing sound...

Tesla bladeless turbomachines are recently being investigated due to many advantages such as its simple design and ease of manufacturing. If an efficient design is achieved, this will be a promising machine in the area of small-scale power generation and energy harvesting. This paper focuses on the experimental performance investigation of 3 kW...

The aim of this work is to explore the possibilities to find surge precursors from compressor vibro-acoustic analysis in a condition close to instability. For this purpose, a large campaign of data acquisition has been conducted by Thermochemical Power Group (TPG) of University of Genoa: T100 micro-turbine, equipped with three different...