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[EN] In this paper, the unsteady behaviour of a compression-ignited (CI) engine combustion chamber is studied by analysing the results of a Computational Fluid Dynamics (CFD) model through the application of different flow decomposition techniques, aiming to resolve the underlying modal structure of the process. Experimental validation for the combustion simulation is provided, and a methodology for extracting coherent pressure information is proposed in order to provide a suitable input for different analysis methods. These range from straightforward Fourier transform techniques to more sophisticated modal decomposition approaches. In particular Proper Orthogonal Decomposition (POD) is shown to provide valuable insight into the time-spatial structure of the combustion flow field, allowing the establishment of correlations between pressure modes and physical parameters of the combustion, such as the injection timing or the chamber geometry. Dynamic Mode Decomposition (DMD) on the other hand is proven to successfully highlight the link between the frequency of the unsteady energy components and their spatial distribution within the chamber. Advantage is then taken of the modal characterization of the unsteady behaviour in the chamber to showcase how physical parameters such as the spray angle can be modified to optimize the acoustic signature of the combustion process, helping CI internal combustion engines reduce their acoustic environmental impact (C) 2017 The Combustion Institute. Published by Elsevier Inc. All rights reserved. ; The equipment used in this work has been partially supported by FEDER project funds "Dotacidn de infraestructuras cientifico tecnicas para el Centro Integral de Mejora Energetica y Medioambiental de Sistemas de Transporte (CiMeT)" [grant number FEDER-ICTS-2012-06], framed in the operational program of unique scientific and technical infrastructure of the Spanish Government. ; Torregrosa, AJ.; Broatch, A.; Garcia Tiscar, J.; Gómez-Soriano, J. (2018). Modal decomposition of the unsteady ...

[EN] This paper reports the results of an experimental campaign where four different inlet geometries for the compressor of an automotive turbocharger were acoustically characterized. These four geometries (a straight pipe for reference, a tapered duct, a 90º elbow and a reservoir) were selected for their potential for deep surge margin enhancement, while being simple enough to be commonly found in production vehicles. A detailed measurement of this surge margin enhancement was performed, together with acoustic measurements of both radiated and orifice noise at design conditions of best isentropic efficiency and also close to the deep surge limit. Results demonstrated that while all the proposed geometries indeed enlarged the usable air mass flow range, changes in the acoustic behaviour of the system could be positive, neutral, or even negative. It is therefore important to carefully consider accurate noise measurements before implementing these geometric solutions in production vehicles, and to further pursue research on the link between the characteristic flow pattern produced by each inlet geometry and the noise emission of the turbocompressor. ; The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: The equipment used in this work has been partially supported by FEDER project funds ''Dotacio´n de infraestructuras cientı´fico te´cnicas para el Centro Integral de Mejora Energe´tica y Medioambiental de Sistemas de Transporte (CiMeT)'' (grant number FEDER-ICTS-2012-06), framed in the operational program of unique scientific and technical infrastructure of the Spanish Government. ; Broatch, A.; Margot, X.; Garcia Tiscar, J.; Roig-Villanueva, F. (2018). Impact of simple surge-enhancing inlet geometries on the acoustic behaviour of a turbocompressor. International Journal of Engine Research. https://doi.org/10.1177/1468087418784125 ; S

[EN] As the focus of research and development is put into innovative combustion concepts with the goal of reducing harmful chemical pollutants while keeping or even improving the efficiency of conventional Diesel combustion, it is necessary to consider the impact on noise pollution brought by those innovative concepts. However, the question arises as to what extent the noise characterization and optimization strategies currently applied to conventional Diesel compression-ignited engines are applicable to these innovative combustion concepts. In this paper, we apply experimental noise characterization techniques based on pressure trace decomposition to two compression-ignited engines: a baseline conventional Diesel engine and an innovative 2-stroke engine operating with the gasoline partially premixed combustion concept. Analysis of the results reveals that the underlying physical phenomena responsible for the spectral signature of the noise are still shared between the new and the conventional concepts. However, results evince a significant change in the relevance of these physical sources, leading to necessary changes in optimization strategies for future compression-ignited engine development. ; The equipment used in this work has been partially supported by FEDER project funds "Dotacion de infraestructuras cientifico tecnicas para el Centro Integral de Mejora Energetica y Medioambiental de Sistemas de Transporte (CiMeT)" [Grant No. FEDER-ICTS-2012-06], framed in the operational program of unique scientific and technical infrastructure of the Spanish Government. J. Gomez-Soriano is partially supported through the Programa de Apoyo para la Investigacion y Desarrollo (PAID) of Universitat Politecnica de Valencia [Grant No. FPI-S2-2016-1353] ; Broatch, A.; Novella Rosa, R.; Garcia Tiscar, J.; Gómez-Soriano, J. (2019). On the shift of acoustic characteristics of compression-ignited engines when operating with gasoline partially premixed combustion. Applied Thermal Engineering. 146:223-231. ...

[EN] During the last years, it is well known that the curricula of the different engineering firms have undergone drastic changes in all the countries belonging to the European Union. Specifically, one of the concepts that can be derived from the application of the Bologna Plan, and with which the Universitat Politècnica de València is specially committed, is the need to provide the student with a series of transversal competences, common to all similar degrees. , that are of help to him during the development of his professional life. One of the most widespread methods for the development of these competences is the design of group work for practical application. This work proposes a group project, developed within the framework of the subject of the third year of the Aerospace Engineering Degree (GIA), consisting of the design and construction of a glider demonstrator, with the aim of treating, jointly, several of the specific and transversal competences of the degree. A detailed description will be made of the design of the project and an analysis of the results obtained after its application, from the academic year 2015-2016 in the subject Aerospace Technology II ; [ES] Durante los últimos años, es bien sabido que los planes de estudio de las diferentes ingenierías han sufrido drásticos cambios en todos los países pertenecientes a la Unión Europea. En concreto, uno de los conceptos que se pueden derivar de la aplicación del Plan Bolonia, y con el que la Universitat Politècnica de València está especialmente comprometida, es la necesidad de proporcionar al alumno una serie de competencias trasversales, comunes a todas las titulaciones semejantes, que le sean de ayuda durante el desarrollo de su vida profesional. Uno de los métodos más extendidos para el desarrollo de estas competencias consiste en el diseño de trabajos en grupo de aplicación práctica. Este trabajo propone un proyecto grupal, desarrollado en el marco de la asignatura de tercer curso del Grado de Ingeniería Aeroespacial (GIA), consistente en el ...