Résumé -Modèles de spray dans les applications moteur, des corrélations aux simulations numériques directes -Les sprays sont parmi les principaux facteurs de qualité, dans la formation du mélange et la combustion, dans un grand nombre de moteurs (à combustion interne). Ils sont de toute première importance dans la formation de polluants et l'efficacité énergétique, bien qu'une modélisation adéquate soit encore en développement. Pour un grand nombre d'applications, la validation et la calibration de ces modèles demeurent une question ouverte. Aussi, présentons-nous un aperçu des modèles existants et proposons quelques voies d'amélioration. Les modèles sont classés en nondimensionnels et dimensionnels allant de formules simples dédiées à des applications proches du temps réel à des descriptions détaillées des premiers stades de l'atomisation. Abstract -Spray Atomization Models in Engine Applications
International audienceThis article presents an electro-thermal model of a stack of three lithium ion batteries for automotive applications. This tool can help to predict thermal behaviour of battery cells inside a stack. The open source software OpenFOAM provides the possibility to add heat generation because of Joule losses in a CFD model. Heat sources are introduced at the connectors and are calculated as a function of battery discharge current and internal resistance. The internal resistance is described in function of temperature. Simulation results are validated against experimental results with regard to cooling air flow field characteristic and thermal behaviour of the cell surface. The validation shows that the simulation is capable to anticipate air flow field characteristics inside the battery box. It also predicts correctly the thermal behaviour of the battery cells for various discharge rates and different cooling system conditions. The simulation supports the observation that batteries have a higher temperature close to the connectors and that the temperature increase depends highly on discharge rate and cooling system conditions. Copyright (C) 2016 John Wiley & Sons, Ltd
Abstract-PHP is by far the most popular WEB scripting language, accounting for more than 80% of existing websites. PHP is dynamically typed, which means that variables take on the type of the objects that they are assigned, and may change type as execution proceeds. While some type changes are likely not harmful, others involving function calls and global variables may be more difficult to understand and the source of many bugs. Hack, a new PHP variant endorsed by Facebook, attempts to address this problem by adding static typing to PHP variables, which limits them to a single consistent type throughout execution. This paper defines an empirical taxonomy of PHP type changes along three dimensions: the complexity or burden imposed to understand the type change; whether or not the change is potentially harmful; and the actual types changed. We apply static and dynamic analyses to three widely used WEB applications coded in PHP (WordPress, Drupal and phpBB) to investigate (1) to what extent developers really use dynamic typing, (2) what kinds of type changes are actually encountered; and (3) how difficult it might be to refactor the code to avoid type changes, and thus meet the constraints of Hack's static typing.We report evidence that dynamic typing is actually a relatively uncommon practice in production PHP programs, and that most dynamic type changes are simple representational changes, such as between strings and integers. We observe that most PHP type changes in these programs are relatively simple, and that the largest proportion of them are easy to refactor to consistent static typing using simple local renaming transformations. Overall, the paper casts doubt on the usefulness of dynamic typing in PHP, and indicates that for many production applications, conversion to Hack's static typing may not be very difficult.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.