Giovanni Vichi

• University of Florence

div class="section abstract"> The use of hydrogen in port fuel injection (PFI) engines faces challenges related to abnormal combustions that must be addressed, especially in transient operation. The in-cylinder air-to-fuel ratio and the amount of trapped exhaust gas have a significant impact on the probability of abnormal combustion as well as NOx...

div class="section abstract"> Increasingly stringent regulations on engine emissions require strict control of nitrogen oxide (NOx) emissions in diesel engines. Feedback control systems coupled with virtual sensors for real-time NOx readings have shown to be effective solutions for managing emissions. The authors of this paper propose a machine lea...

div class="section abstract"> The possibility to operate current diesel engines in dual-fuel mode with the addition of an alternative fuel is fundamental to accelerate the energy transition to achieve carbon neutrality. The simulation of the dual- fuel combustion process with 0D/1D combustion models is fundamental for the performance prediction, bu...

Real-time estimation of the in-cylinder pressure of combustion engines is crucial to detect failures and improve the performance of the engine control system. A new estimation scheme is proposed based on the Extended Kalman Filter, which exploits measurements of the engine rotational speed provided by a standard phonic wheel sensor. The main novelt...

Modern engines require continuous and detailed monitoring in order to minimize variations in performance and emissions during their operation. To this aim, the engine thermodynamic cycle must be brought into focus, with special emphasis on the combustion process. The in-cylinder pressure is the parameter that is most directly associated with the en...

In the field of Internal Combustion Engines (ICEs), increasingly stricter regulations on pollutant emissions have made necessary to continuously monitor engine operation. Indeed, in order to tackle fault-induced variations in engine performance, continuous, real-time data related to the engine’s thermodynamic cycle is needed: specifically, obtainin...

In the last ten years, Machine Learning (ML) and Artificial Intelligence (AI) have overwhelmed every engineering research branch finding a broad variety of applications; anomaly detection and anomaly classification are two of the topics that have benefited mostly by data-driven methods’ insights. On the other side, in the small diesel engine domain...

In case of stationary power production, the matching between the turbocharger and the engine can be optimized around a specific operating point, rather than throughout a wide range like in automotive applications. This, in turn, may enable a finer optimization of the aerodynamic efficiency in comparison to existing industrial standards. The present...

The increasing attention in reducing pollutant emissions and fuel consumption in internal combustion engines is promoting the development of more sophisticated control systems for the diagnosis and the optimization of the combustion process. In this view, the real-time monitoring of the in-cylinder pressure is becoming mandatory in order to ensure...

The increasingly strict European emissions standards are prompting researchers at improving further the combustion process in internal combustion engines, in order to reduce pollutant emissions and fuel consumption. To this end, more effective monitoring and control strategies need to be developed in the near future. In particular, the development...

In order to ensure a high level of performance and to comply with the increasingly severe limitations in terms of fuel consumption and pollution emissions, modern diesel engines need continuous monitoring of their operating conditions by their control units. With particular focus on turbocharged engines, which are presently the standard in a large...

The increasing application of new concepts for the combustion process in internal combustion engines, e.g. HCCI or RCCI, is mainly aimed at reducing pollutant emissions and fuel consumption. A typical drawback of these technologies is the difficulty of properly controlling the combustion process in the area of medium-high brake mean effective press...

Recent innovations in engine control and diagnostics are providing room for development of innovative combustion approaches (e.g., low-temperature combustion) able to minimize the creation of pollutants. To ensure the constant fulfillment of the prescribed thermodynamic conditions, however, a fast real-time monitoring of the in-cylinder pressure is...

The main drawbacks of two stroke (2S) engines consist in poor engine efficiency and high level of pollutant emissions. The contemporary opening of transfer and exhaust ports during the scavenging process causes the short circuit of fresh air-fuel mixture in case of indirect injection or carbureted engines. Despite the intrinsic strengths such as hi...

The engine and vehicle design in Formula SAE competition has to accomplish a strict regulation. In order to limit the maximum power, an air restrictor of 20mm of diameter is imposed in the intake line. To overcome the limitations caused by the restrictor, Firenze Race Team equipped its one-cylinder engine with a turbocharger, which is conventionall...

The Formula SAE is an international competition for vehicle fully designed and built by students from worldwide Universities.

The paper investigates the influence of the fuel injection pressure on a small two-stroke engine with low pressure direct injection (LPDI). The authors in previous studies showed the benefits of the LPDI system in reducing the fuel short circuit, both from an experimental and numerical point of view. As a direct consequence, both the specific fuel...

A typical issue of the two-stroke engine in monitoring the combustion process is to measure the actual burning mixture with a conventional 02-sensor placed in the exhaust duct. In fact, the short circuit of fresh charge affects the correct acquisition of the residual oxygen associated to the completeness of the combustion process, leading to the ov...

In order to ensure a high level of performance and to comply with more severe limitations in term of fuel consumption and emissions reduction, a continuous supervision of the engine operating conditions, by monitoring several parameters, is needed. The growing use of turbocharger (TC) in ICE for automotive and industrial applications suggests to u...

High specific fuel consumption and pollutant emissions are the main drawbacks of the small crankcase-scavenged two-stroke engine. The symmetrical port timing combined with a carburetor or an indirect injection system leads to a lower scavenging efficiency than a four-stroke engine and to the short-circuit of fresh air-fuel mixture. The use of fuel...

High specific fuel consumption and pollutant emissions are the main drawbacks of the small crankcase-scavenged two-stroke engine. The symmetrical port timing combined with a carburetor or an indirect injection system leads to a lower scavenging efficiency than a four-stroke engine and to the short-circuit of fresh air-fuel mixture. The use of fuel...

In the last years, the engineering in the automotive industry is revolutionized by the continuous research of solutions for the reduction of consumptions and pollutant emissions. On this topic maximum attention is paid by both the legislative bodies and the costumers. The more and more severe limitations in pollutant and CO2 emissions imposed by in...

The intake and exhaust lines provide the main abatement of the acoustic emissions of an Internal Combustion Engine (ICE). Many different numerical approaches can be used to evaluate the acoustic attenuation, which is commonly expressed by the Transmission Loss. One-dimensional (1D) and three-dimensional (3D) simulations are conventionally carried o...

A condition monitoring activity consists in the analysis of several information from the engine and the subsequent data elaboration to assess its operating condition. By means of a continuous supervision of the operating conditions the internal combustion engine performance can be maintained at design-level in the long term. The growing use of turb...

Two-stroke engines complete the process cycle in one crankshaft revolution: the scavenging process takes place when the piston is close to the bottom dead center, with the opportunity to open and close the cylinder ports by means of the piston motion, greatly reducing the number of moving parts. This solution however, typically used in small engine...

In current automotive research, increasing attention is being paid to the design of mufflers due to the lower noise levels which have been established by the acoustic international standards. The traditional design approaches are no longer sufficient to meet the standards and more refined techniques are necessary. Within this context, a specific te...

Increasing interest is being paid to noise pollution of internal combustion engines and as a result, recent international standards imposed more severe limitations to acoustic emissions on engine manufacturers. In particular, the noise coming from gas-dynamic interactions has an important influence in determining the final noise level of the engine...

Design and optimization of intake and exhaust systems and valve timing is crucial in development of a naturally aspirated engine. Nowadays numerical simulation is a fundamental tool for this area. Unfortunately to perform an optimization of engine performance by setting even only a few parameters needs great effort in terms of time and engineering...