117 research outputs found
Eugenio d'Ors y el pragmatismo
El objetivo de este trabajo es dar noticia de la recepción del pragmatismo en la obra y el pensamiento de Eugenio d’Ors, reuniendo algunos resultados de nuestros trabajos preceden- tes. Dedicamos una primera parte a describir el encuentro de Eugenio d’Ors con el pragmatismo. En segundo lugar describimos su conexión con William James a quien llegó a conocer en París. En tercer lugar, damos cuenta de en qué consiste la denominada “superación del pragmatismo” por parte de Eugenio d’Ors y, por último, señalamos las afinidades más relevantes de su pensamiento con algunas de las intuiciones más originales del pragmatismo de Charles S. Peirce
Application of magnetic cooling in electric vehicles
The features of an active magnetic regenerator refrigerator (AMRR) are determined for its application in mobile air-conditioning (MAC) systems. The thermal requirements of an electric vehicle have been firstly obtained and result in a cooling demand of 3.03 kW at a temperature span of 29.3 K. A comprehensive parametric study has been conducted in order to find the AMRR design and working parameters that fulfill the vehicle needs with a minimum electric consumption and device mass. Specifically, a permanent-magnet parallel-plate AMRR made of Gd-like materials is considered. According to the possibilities of current prototypes, in the study the cycle frequencies have been limited to 10 Hz and the applied magnetic fields, to 1.4 T. The results show that an AMRR made of plates between 30 and 40 µm thick and channels between 20 and 40 µm high could meet the vehicle demand with a COP between 2 and 4 and a total mass between 20 and 50 kg. Compared to vapor-compression devices for MAC systems (COP=2.5 and mass 12 to 15 kg), the AMRR works optimally with fluid flow rates at least 3 times larger. In order to integrate AMRRs into MAC systems, the hydraulic loops should be consequently redesigned.Barbara Torregrosa-Jaime acknowledges the Spanish Ministry of Education, Culture, and Sport (Ministerio de Educacion, Cultura y Deporte) for the Research Fellowship FPU ref. AP2010-2160.Torregrosa Jaime, B.; Payá Herrero, J.; Corberán Salvador, JM. (2016). Application of magnetic cooling in electric vehicles. Science and Technology for the Built Environment. 22(5):544-555. doi:10.1080/23744731.2016.1186459S54455522
Sizing of a reversible magnetic heat pump for the automotive industry
[EN] This paper focuses on the design of an innovative air-conditioning system, namely a magnetocaloric air-conditioner for an electric minibus. An integrated design of the complete system is necessary, as the hot and cold side of the regenerator will work under dynamic conditions which depend on the instantaneous thermal load in the cabin.
In order to assist the design of the system, a dynamic model has been developed for the cabin, the hydraulic loops and heat exchangers, and the magnetocaloric unit. This paper presents (i) a description of the dynamic models, (ii) an analysis of the operating conditions of the magnetocaloric unit and (iii) a discussion on the design of the magnetocaloric air-conditioner. The results show that the electric minibus requests 1.60 kW of cooling power over a span of 37 K in cooling mode, and 3.39 kW of heating power over a span of 40 K.This work has been supported by the European Commission under the 7th European Community framework program as part of the ICE project "MagnetoCaloric Refrigeration for Efficient Electric Air-Conditioning", Grant Agreement no. 265434. B. Torregrosa-Jaime acknowledges the Spanish Science and Innovation Ministry (Ministerio de Ciencia e Innovacion) for receiving the Research Fellowship FPU ref. AP2010-2160.Torregrosa Jaime, B.; Corberán Salvador, JM.; Vasile, C.; Muller, C.; Risser, M.; Payá Herrero, J. (2014). Sizing of a reversible magnetic heat pump for the automotive industry. International Journal of Refrigeration. 37:156-164. https://doi.org/10.1016/j.ijrefrig.2013.06.018S1561643
Estimation of the in-cylinder residual mass fraction at Intake Valve Closing in a 2-stroke High-Speed Direct-Injection Compression-Ignition engine
This is the author's version of a work that was accepted for publication in International Journal of Engine Research. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting,
and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published as https://doi.org/10.1177/1468087418813406.[EN] New combustion concepts and engine designs are being currently investigated in order to comply with upcoming pollutant regulations and reduce fuel consumption. In this context, two-stroke architectures appear as a promising solution for the implementation of some combustion concepts. However, scavenging processes in a two-stroke engine are much more challenging than for a four-stroke engine, and the residual mass of burnt gases retained inside the cylinder needs to be properly determined in order to keep control over the in-cylinder composition, hence over the combustion conditions and pollutant emissions. In this study, a new methodology for the estimation of the internal residual gas fraction is introduced, which is based on the thermodynamic processes occurring in the engine investigated and makes use of basic engine instrumentation and measurement equipment usually available in a conventional test cell. Several versions of the estimator were developed so that different requirements could be met, such as those of real-time estimation on an engine test bench but with reduced precision or, on the contrary, highly precise but time-consuming computations for post-processing purposes and combustion diagnosis. The consistency of the internal residual gas estimator was then validated through its application to real engine tests at different operating points.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This research has been sponsored by the European Union in framework of the REWARD project, Horizon 2020 research and innovation program under grant agreement no. 636380. The authors kindly recognize the technical support provided by Mr Gilles Coma and his research group at RENAULT SAS, and also by the research group at IFPEN, along the development of the investigations presented here.Torregrosa, AJ.; Martín, J.; Novella Rosa, R.; Thein, K. (2020). Estimation of the in-cylinder residual mass fraction at Intake Valve Closing in a 2-stroke High-Speed Direct-Injection Compression-Ignition engine. 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Energy, 35(5), 2251-2260. doi:10.1016/j.energy.2010.02.012Olsen, D. B., Hutcherson, G. C., Willson, B. D., & Mitchell, C. E. (2002). Development of the Tracer Gas Method for Large Bore Natural Gas Engines—Part I: Method Validation. Journal of Engineering for Gas Turbines and Power, 124(3), 678-685. doi:10.1115/1.1454116Olsen, D. B., Hutcherson, G. C., Willson, B. D., & Mitchell, C. E. (2002). Development of the Tracer Gas Method for Large Bore Natural Gas Engines—Part II: Measurement of Scavenging Parameters. Journal of Engineering for Gas Turbines and Power, 124(3), 686-694. doi:10.1115/1.1454117Benajes, J., Olmeda, P., Martín, J., & Carreño, R. (2014). A new methodology for uncertainties characterization in combustion diagnosis and thermodynamic modelling. Applied Thermal Engineering, 71(1), 389-399. doi:10.1016/j.applthermaleng.2014.07.010Payri, F., Olmeda, P., Martín, J., & García, A. (2011). A complete 0D thermodynamic predictive model for direct injection diesel engines. 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¿ÁMBITO CIENTÍFICO O ASIGNATURAS?
A polémica que se gerou em algumas comunidades em Espanha pelo desenvolvimento de um sistema de ensino científico na primeira fase do Ensino Secundário Obrigatório (ESO), baseado na ideia de "Campo Científico" em vez de disciplinas e na possibilidade de que, longe de sendo uma medida excepcional de natureza específica provocada pela COVID19, poderá continuar ou ser ampliada ao abrigo da nova Lei da Educação (LOMLOE), é um assunto sobre o qual, como professores, investigadores e cidadãos, nos sentimos obrigados a comentar. É uma questão de grande importância, que afeta ou pode afetar também outros países e que tem basicamente duas vertentes: sociopolítica e científico-educacional. Neste artigo, ambos são brevemente discutidos
Compact High-Pressure Intake Silencer with Multilayer Porous Material
Intake noise has become one the main concerns in the design of highly-supercharged downsized engines, which are expected to play a
significant role in the upcoming years. Apart from the low frequencies associated with engine breathing, in these engines other
frequency bands are also relevant which are related to the turbocharger operation, and which may radiate from the high-pressure side
from the compressor outlet to the charge air cooler. Medium frequencies may be controlled with the use of different typologies of
resonators, but these are not so effective for relatively high frequencies. In this paper, the potential of the use of multi-layer porous
materials to control those high frequencies is explored. The material sheets are located in the side chamber of an otherwise
conventional resonator, thus providing a compact, lightweight and convenient arrangement. Several configurations have been tested in
an impulse rig, without and with a superimposed mean flow, and the results have been analyzed with the help of a simple linear finite
volume model accounting for the material. Then, the model has been used to explore different combinations of geometry and material
properties, with the purpose of defining design guidelines for a proper choice of the device size and the material used, that may allow
fulfilling the targeted value.Torregrosa, AJ.; Broatch Jacobi, JA.; Raimbault, V.; Migaud, J. (2016). Compact High-Pressure Intake Silencer with Multilayer Porous Material. SAE International Journal of Passenger Cars. Mechanical Systems. 9(3):1-8. doi:10.4271/2016-01-1819S189
Planificando la enseñanza problematizada : el ejemplo de la óptica geométrica en educación secundaria
La planificación de la enseñanza problematizada de los temas requiere seleccionar una meta orientadora (qué nos gustaría conseguir con nuestros alumnos en el tema a tratar), un problema estructurante e identificar grandes pasos que permiten avanzar en su solución y posibles obstáculos asociados. Estas decisiones se basan en un estudio histórico, epistemológico y de la investigación didáctica ya realizada en el campo (Duit et al., 2005; Furió et al., 2006; Verdú et al., 2002). Antes de la concreción de esta planifi cación en una secuencia de actividades para el aula (programa-guía), su relevancia potencial para la mejora de la enseñanza es sometida a pruebas mediante un estudio empírico. En este artículo presentamos los resultados de este proceso para la enseñanza del modelo de visión de Kepler en la etapa secundaria, cuya apropiación hemos considerado la meta orientadora de la enseñanza de la óptica geométrica en este nivel educativo.Planning problem-based teaching and learning topics requires to choose a guiding aim (what we would like to achieve for our students with the topic to deal with), a structural problem, and also to identify the big steps to reach its solution together with the possible associated obstacles. These decisions are based on a historical and epistemological study and on the previous educational research in the field (Duit et al2005; Furió et al, 2006; Verdú et al, 2002). The potential importance of these decisions to improve teaching and learning is tested by means of an empirical study. The data gained in this empirical study are then used to make a sequence of activities for the classroom into the problematized framework initially selected. In this paper we show the results of such a process in planning problem-based light and vision's teaching in Secondary Education (14-16 years old students)
Experimental methodology for turbocompressor in-duct noise evaluation based on beamforming wave decomposition
An experimental methodology is proposed to assess the noise emission of centrifugal turbocompressors like those of automotive turbochargers. A step-by-step procedure is detailed, starting from the theoretical considerations of sound measurement in flow ducts and examining specific experimental setup guidelines and signal processing routines. Special care is taken regarding some limiting factors that adversely affect the measuring of sound intensity in ducts, namely calibration, sensor placement and frequency ranges and restrictions. In order to provide illustrative examples of the proposed techniques and results, the methodology has been applied to the acoustic evaluation of a small automotive turbocharger in a flow bench. Samples of raw pressure spectra, decomposed pressure waves, calibration results, accurate surge characterization and final compressor noise maps and estimated spectrograms are provided. The analysis of selected frequency bands successfully shows how different, known noise phenomena of particular interest such as mid-frequency "whoosh noise" and low-frequency surge onset are correlated with operating conditions of the turbocharger. Comparison against external inlet orifice intensity measurements shows good correlation and improvement with respect to alternative wave decomposition techniques.The equipment used in this work has been partially supported by the Spanish Ministerio de Economia y Competitividad through grant no. TRA2012-36954 and by FEDER project funds "Dotacion de infraestructuras cientifico-tecnicas para el Centro Integral de Mejora Energetica y Medioambiental de Sistemas de Transporte (CiMeT), (FEDER-ICTS-2012-06)" framed in the operational program of unique scientific and technical infrastructure of the Spanish Ministerio de Economia y Competitividad. J. Garcia-Tiscar is partially supported through contract FPI-S2-2015-1530 of the Programa de Apoyo para la Investigacion y Desarrollo (PAID) of Universitat Politecnica de Valencia.Torregrosa, AJ.; Broatch Jacobi, JA.; Margot, X.; García Tíscar, J. (2016). Experimental methodology for turbocompressor in-duct noise evaluation based on beamforming wave decomposition. Journal of Sound and Vibration. 376:60-71. https://doi.org/10.1016/j.jsv.2016.04.035S607137
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