turbocharger speed estimation via vibration measurements for combustion sensing

Abstract Monitoring of engine operating condition is essential to comply with severe limitations of harmful exhaust emissions and fuel consumption. Several strategies have been proposed, in which different types of sensors are used for the direct/indirect combustion sensing and to provide a feedback signal to optimize the process. It has been demonstrated that in a turbocharged engine a relationship exists between the rotational speed of the turbocharger and the thermo-fluid dynamic condition of the gases at the exhaust valve opening. Such a relation allows to establish a link between the engine operating conditions in terms of speed, load and injection settings and the turbocharger speed. This work presents a methodology devoted to extract from an accelerometer signal, the mean turbocharger rotational speed with the final aim of realizing a non intrusive control of combustion process, in which the variation of combustion development as regards nominal condition is detected via the estimation of the turbocharger speed

vibration analysis to estimate turbocharger speed fluctuation in diesel engines

Abstract The optimum management of the engine system has a crucial role in order to achieve high efficiency and reduced pollutant emissions. Advanced methods have been proposed, in which several types of sensors are used to directly/indirectly sense the combustion and to provide a feedback signal to optimize the engine management. In turbocharged engines, it has been demonstrated that a relationship exists between the rotational speed of the turbocharger and the thermo-fluid dynamic condition of the gases at the exhaust valve opening. Such a relation allows to establish a link between the engine operating conditions in terms of speed, load and injection settings and the turbocharger speed. A research activity was performed aimed at developing a methodology in which the signal from an accelerometer mounted on the compressor housing was used to extract information about the turbocharger speed value. The activity was organized in two subsequent steps, each one focused on one specific objective: – estimation of the mean turbocharger rotational speed – evaluation of the turbocharger speed fluctuations. Tests were performed on a small displacement two-cylinder diesel engine mainly used in urban vehicles that was equipped with a turbocharger. The results obtained during the first step of activity demonstrated the opportunity of further investigations in order to compute the turbocharger speed fluctuation from the accelerometer signal processing. This paper is devoted to present the results of the second step of the research activity, with the final aim of realizing a non intrusive control of combustion process, in which the variation of combustion development as regards nominal condition is detected via the estimation of the turbocharger speed

Soot Particles Experimental Characterization During Cold Start of a Micro Car Engine

Abstract Substantial amount of pollutants is emitted during the vehicle start-up, since the engine has not reached its optimal operating temperature. In urban traffic environment, the engine emissions during its warming up until it reaches a hot stabilized mode are an important source of major air pollutants. Existing literature indicates that: - in recent years the vehicle emissions have been reduced significantly, while those related to engine cold starts still remain high; - emission levels during engine start-up are deeply influenced by the vehicle characteristics. Most of studies are related to diesel engines equipped with high efficiency DPFs, gasoline port fuel injected and gasoline direct injected engines equipped with three-way-catalysts. This paper aims at characterizing pollutants and solid particles emissions from a low displacement two cylinder diesel engine, whose main application is in city cars and urban vehicles. During tests, measurements started at the time of the engine cold start-up; transient conditions of load and speed were imposed to the engine. A characterization of solid particle was performed, in terms of particle number and size distribution for three engine thermal conditions: cold, warm and hot starts

Altered Erythropoiesis in Mouse Models of Type 3 Hemochromatosis

Type 3 haemochromatosis (HFE3) is a rare genetic iron overload disease which ultimately lead to compromised organs functioning. HFE3 is caused by mutations in transferrin receptor 2 (TFR2) gene that codes for two main isoforms (Tfr2α and Tfr2β). Tfr2α is one of the hepatic regulators of iron inhibitor hepcidin. Tfr2β is an intracellular isoform of the protein involved in the regulation of iron levels in reticuloendothelial cells. It has been recently demonstrated that Tfr2 is also involved in erythropoiesis. This study aims to further investigate Tfr2 erythropoietic role by evaluating the erythropoiesis of two Tfr2 murine models wherein either one or both of Tfr2 isoforms have been selectively silenced (Tfr2 KI and Tfr2 KO). The evaluations were performed in bone marrow and spleen, in 14 days’ and 10 weeks’ old mice, to assess erythropoiesis in young versus adult animals. The lack of Tfr2α leads to macrocytosis with low reticulocyte number and increased hemoglobin values, together with an anticipation of adult BM erythropoiesis and an increased splenic erythropoiesis. On the other hand, lack of Tfr2β (Tfr2 KI mice) causes an increased and immature splenic erythropoiesis. Taken together, these data confirm the role of Tfr2α in modulation of erythropoiesis and of Tfr2β in favoring iron availability for erythropoiesis

Recurrent, founder and hypomorphic variants contribute to the genetic landscape of Joubert syndrome

Background Joubert syndrome (JS) is a neurodevelopmental ciliopathy characterised by a distinctive mid-hindbrain malformation, the 'molar tooth sign'. Over 40 JS-associated genes are known, accounting for two-thirds of cases.Methods While most variants are novel or extremely rare, we report on 11 recurring variants in seven genes, including three known 'founder variants' in the Ashkenazi Jewish, Hutterite and Finnish populations. We evaluated variant frequencies in similar to 550 European patients with JS and compared them with controls (>15 000 Italian plus gnomAD), and with an independent cohort of similar to 600 JS probands from the USA.Results All variants were markedly enriched in the European JS cohort compared with controls. When comparing allele frequencies in the two JS cohorts, the Ashkenazim founder variant (TMEM216 c.218G>T) was significantly enriched in American compared with European patients with JS, while MKS1 c.1476T>G was about 10 times more frequent among European JS. Frequencies of other variants were comparable in the two cohorts. Genotyping of several markers identified four novel European founder haplotypes. Two recurrent variants (MKS1 c.1476T>G and KIAA0586 c.428delG), have been detected in homozygosity in unaffected individuals, suggesting they could act as hypomorphic variants. However, while fibroblasts from a MKS1 c.1476T>G healthy homozygote showed impaired ability to form primary cilia and mildly reduced ciliary length, ciliary parameters were normal in cells from a KIAA0586 c.428delG healthy homozygote.Conclusion This study contributes to understand the complex genetic landscape of JS, explain its variable prevalence in distinct geographical areas and characterise two recurrent hypomorphic variants

Linguaggio e conoscenza in J. R. Searle

Dottorato di ricerca in filosofia. 11. ciclo. Tutore C. MontaleoneConsiglio Nazionale delle Ricerche - Biblioteca Centrale - P.le Aldo Moro, 7, Rome; Biblioteca Nazionale Centrale - P.za Cavalleggeri, 1, Florence / CNR - Consiglio Nazionale delle RichercheSIGLEITItal

Multi-step approaches for comprehensive modeling of diesel engine fuel injection processes

The overall optimization of diesel fuel injection equipment and combustion process is mandatory to fulfill the future emission regulations. Among the involved phenomena, a preliminary role is played by the strong link between the combustion behavior and the adopted strategies to promote the mixing of reactants. The aim of the present work is to develop a comprehensive modeling approach, having the capability to take the deep connection between fuel injection phenomena into account. For this scope, different computational tools, characterized by different roles, have been used and coupled, accounting for the interdependencies of the relevant sub-processes. Three main multi-step modeling approaches are outlined and then used in the analysis of practical cases; these can be summarized as follows: 1) multi-step modeling (0D-3D CFD) for injection process and spray simulation with a unitary approach; 2) double step modeling (3D-0D) of fuel metering component operation; 3) comprehensive multi-step lumped modeling of injection system operation, spray formation and fuel vaporization. The mechanical-hydraulic modeling of the injection systems is based on the 0-1D code AMESim. To model the in-cylinder flows and the 3D transient nozzle flow, the commercial FIRE code is used, whereas the lumped modeling of evaporation processes in cylinder ambient is self FORTRAN implemented. Several cases have been considered and the contribution of the modeling approach is presented evaluated. Two different injection system types (inline pump and common rail systems) are considered in the applications. Investigations are devoted to evaluate the influence on injection process of fuel characteristics and composition, injection strategies, injector layout, geometrical features and needle operating conditions