661 research outputs found
Multidimensional Modeling of Natural Gas Jet and Mixture Formation in Direct Injection Spark Ignition Engines—Development and Validation of a Virtual Injector Model
No full textDuring the last few years, the integration of CFD tools in the internal combustion (IC) engine design process has continually increased, allowing time and cost savings as the need for experimental prototypes has diminished. Numerical analyses of IC engine flows are rather complex from both the conceptual and operational sides. In fact, these flows involve a variety of unsteady phenomena and the right balance between numerical solution accuracy and computational cost should always be reached. The present paper is focused on computational modeling of natural gas (NG) direct injection (DI) processes from a poppet-valve injector into a bowl-shaped combustion chamber. At high injection pressures, the gas efflux from the injector and the mixture formation processes include turbulent and compressible flow features, such as rarefaction waves and shock formation, which are difficult to accurately capture with numerical simulations, particularly when the combustion chamber geometry is complex and the piston and intake/exhaust valve grids are moving. In this paper, a three-dimensional moving grid model of the combustion engine chamber, originally developed by the authors to include simulation of the actual needle lift, has been enhanced by increasing the accuracy in the proximity of the sonic section of the critical valve-seat nozzle, in order to precisely capture the expansion dynamics the methane undergoes inside the injector and immediately downstream from it. The enhanced numerical model was then validated by comparing the numerical results to Schlieren experimental images for gas injection into a constant-volume bomb. Numerical studies were carried out in order to characterize the fuel-jet properties and the evolution of mixture formation for a centrally mounted injector configuration in the case of a pancake-shaped test chamber and the real engine chamber. Finally, the fluid properties calculated by the model in the throat section of the critical nozzle were taken as reference data for developing a new effective virtual injector model, which allows the designer to remove the whole computational domain upstream from the sonic section of the nozzle, keeping the flow properties virtually unchanged there. The virtual injector model outcomes were shown to be in very good agreement with the results of the enhanced complete injector model, substantiating the reliability of the proposed novel approach.</jats:p
Computational and Experimental Analysis of Direct CNG Injection and Mixture Formation in a SI Research Engine
No full text
Mirko Breyer, Publisher from Križevci
No full textU tekstu se donosi kratak prikaz života i djela križevačkog nakladnika Mirka Breyera. Mirko Breyer bio je pr\>ak hrvatske bibliografije, bibliofil, knjižar-nakladnik i antikvar. Obilježio je početak dvadesetog stoljeća svojim kulturnim radom. Autor donosi dio objavljene i dio neobjavljene građe o Mirku Breyeru.The text is a short overview of the life and work of a Križevci publisher Mirko Breyer. Mirko Breyer was a pioneer of Croation bibliography, a bibliophile, bookseller, publisher and antiquarian. He marked the beginning of the 20th century with his cultural work. The author presents parts of published as well as unpublished material on Mirko Breyer, with his bibliography
Multidimensional Modeling of Natural GAs Jet and Mixture Formation in DI SI Engines - Development and Validation of a Virtual Injector Model
No full textBiological Functional Relevance of Asymmetric Dimethylarginine (ADMA) in Cardiovascular Disease
No full textThere is growing evidence that increased levels of the endogenous NO synthase inhibitor asymmetric dimethylarginine (ADMA) may contribute to endothelial dysfunction. Studies in animal models as well as in humans have suggested that the increase in ADMA occurs at a time when vascular disease has not yet become clinically evident. ADMA competitively inhibits NO elaboration by displacing L-arginine from NO synthase. In a concentration-dependent manner, it thereby interferes not only with endothelium-dependent, NO-mediated vasodilation, but also with other biological functions exerted by NO. The upshot may be a pro-atherogenic state. Recently, several studies have investigated the effect of various therapeutical interventions on ADMA plasma concentrations. [...
Professor Mirko Škampa - personality portrait
No full textBakalářská práce se zabývá osobností Mirko Škampy. Obsahuje stručný životopis, přehled jeho nejvýznamnějších absolventů a osobní rozhovor s pedagogem. Velkou část práce autor věnuje analýze některých cvičení z jeho metodické publikace – Škola hry na violoncello.The goal of the thesis is to present the personality of Mirko Škampa. It includes a brief biography, an overview of his most famous graduates and an personal interveiw with professor Škampa. The author of this thesis devotes its great part to analyse of some exercises from his methodics – School of cello playing for kids
When children’s perceived and actual motor competence mismatch: gender differences and other issues
No full textProfessor Mirko Bagaric, 2019
No full textLeading sentencing and criminal justice scholar, Professor Mirko Bagaric, has been appointed as the new Dean of Swinburne Law School, where he has been Director of Research for three years.
Professor Bagaric brings vast experience to the role. He was Dean of Law at Deakin University from 2003 to 2006 and 2012 to 2015. He has been a practicing lawyer for 20 years, and is a prolific author and media commentator.
Photograph originally appeared in the Media Centre Release, 'Leading criminal justice scholar appointed new Dean of Swinburne Law School' on Monday 02 December 2019
Postmodern Aspects of Mirko Kovač`s Novels
No full textThis paper deals with postmodern techniquesin of the novels of Mirko Kovač, a prominent figure in the postmodern literature. In particular, the study examinesnarrative strategies which deviate from traditional paradigms and yet create a distinct reality of the text. Postmodern principles such as “the poetic narrator ” (and the “poetic reading ” associated with it), temporal distortion, the questioning of historical facts, hybridization of narrative texts, metatextuality and citationality, documentation, fragmentation and text segmentation will be addressed using concrete examples. Mirko Kovač stands out with his distinctive poetics which contains elements of postmodernism, intertwined with traces of other poetics. In this paper we will dwell precisely on the postmodern aspects of his texts. In weaving the fabric of his texts, the author employs narrative strategies that threaten and break the traditional conventional narrative with its prominent elements such as narrative instance, time, space, composition, characters. All canonised forms and values are reviewed and dissolved in a specific way. In his writings, Kovač makes use of specific forms of citation and documentarity. Special attention in our work shall be devoted to Kovač’s novelistic structures, in which he as an author spans a full creative range. We will try to shed light on all phenomena of the narrative text which are developed in terms of the postmodern
- …
