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A fully-coupled algorithm with implicit surface tension treatment for interfacial flows with large density ratios
Get PDFABSTRACT: The stability of most surface-tension-driven interfacial flow simulations is governed by the capillary time-step constraint. This concerns particularly small-scale flows and, more generally, highly-resolved liquid-gas simulations with moderate inertia. To date, the majority of interfacial-flow simulations are performed using an explicit surface-tension treatment, which restrains the performance of such simulations. Recently, an implicit treatment of surface tension able to breach the capillary time-step constraint using the volume-of-fluid (VOF) method was proposed, based on a fully-coupled pressure-based finite-volume algorithm. To this end, the interface-advection equation is incorporated implicitly into the linear flow solver, resulting in a tight coupling between all implicit solution variables (colour function, pressure, velocity). However, this algorithm is limited to uniform density and viscosity fields. Here, we present a fully-coupled algorithm for interfacial flows with implicit surface tension applicable to interfacial flows with large density and viscosity ratios. This is achieved by solving the continuity and momentum equations in conservative form, whereby the density is treated implicitly with respect to the colour function, and the advection term of the interface-advection equation is discretised using the THINC/QQ algebraic VOF scheme, yielding a consistent discretisation of the advective terms. This new algorithm is tested by considering representative surface-tension-dominated interfacial flows, including the Laplace equilibrium of a stationary droplet and the three-dimensional Rayleigh-Plateau instability of a liquid filament. The presented results demonstrate that interfacial flows with large density and viscosity ratios can be simulated and energy conservation is ensured, even with a time step larger than the capillary time-step constraint, provided that other time-step restrictions are satisfied
Navigating the shift: strategies beyond “build it and they will come” for sustainable mobility in Quebec
Get PDFABSTRACT: Passenger transport is an important contributor to unsustainable urban systems. To achieve the necessary socio-ecological transition will require overcoming the entrenched system of automobility. Composed of several mutually reinforcing components, this system has conferred psychosocial dimensions to car ownership and use that leads to important institutional, political, and individual resistance to change both car-centric transportation infrastructure and individual travel behaviour. For this reason, a growing consensus suggests that transitioning to a sustainable mobility system requires a more holistic approach that applies a synergistic integration of “hard” supply-side measures and “soft” demand-side solutions. This means increasing non-automobile accessibility and supporting such change with soft travel behaviour change solutions that target social-psychological barriers to change. While such approaches have demonstrated their effectiveness around the world, this second category of interventions remains underutilized, particularly in North America. Drawing from social psychology and a North American case study, this chapter proposes a theory-to-practice guide for practitioners to designing effective voluntary travel behaviour change interventions based on the Stage Model of Self-Regulated Behaviour Change (SSBC). A four-level integration framework for intervention design based on the SSBC is proposed. The framework proposes intervention approaches from using the model as a simple diagnostic tool to a complete integration to deliver a fully individualized and stage-tailored intervention. Stage-specific messages and strategies are described to shift people away from car use towards active, collective, and shared mobility options. The chapter concludes on suggestions for collaborative efforts between researchers and practitioners to design, evaluate, and enhance the effectiveness of these interventions, thus moving beyond infrastructure-only solutions to foster a successful transition to sustainable mobility in Québec
Assessing the effect of environmental attitudes on waste material flow quality through agent-based modelling of citizen source separation behaviour
No full textStudy of morphological and optical properties of thin Ag layers prepared by pulsed laser deposition at glancing angle configuration
No full textVulnerability scoring metric of CVSS needs to be adjusted per each product: our analysis on Linux and Apache
No full textFormation documentaire créditée et obligatoire aux cycles supérieurs : contexte et bénéfices pour la clientèle étudiante et le corps professoral
Get PDFRÉSUMÉ: Depuis 2002, la Bibliothèque de Polytechnique Montréal offre des formations documentaires obligatoires et créditées. Plus de 6 500 étudiantes et étudiants aux cycles supérieurs en génie y ont participé. Un sondage effectué au fil des ans révèle que plus de 90 % de la clientèle étudiante est satisfaite des apprentissages réalisés durant les cours. Les étudiantes et étudiants apprécient particulièrement apprendre à créer et exécuter une stratégie de recherche complexe dans une base de données bibliographiques, mais aussi découvrir de nouvelles ressources et en apprendre davantage sur le plagiat et le droit d’auteur. Les résultats d’un sondage auprès du corps professoral font ressortir que ses membres jugent ces formations utiles, une grande majorité d’entre eux indiquant que celles-ci ont permis à leurs étudiantes et étudiants de produire de meilleures revues de littérature. Les facteurs de succès de ces formations comprennent l’aspect crédité et obligatoire, les travaux portant sur le sujet de recherche et l’encadrement par les bibliothécaires. Outre les bénéfices pour la clientèle étudiante et le corps professoral, ces formations documentaires contribuent aussi au développement professionnel des bibliothécaires et amènent les bibliothèques universitaires à faire davantage partie de l’équation pour favoriser le succès des activités de recherche et d’enseignement de leur institution
