Multimodal teaching, learning and training in virtual reality: a review and case study

It is becoming increasingly prevalent in digital learning research to encompass an array of different meanings, spaces, processes, and teaching strategies for discerning a global perspective on constructing the student learning experience. Multimodality is an emergent phenomenon that may influence how digital learning is designed, especially when employed in highly interactive and immersive learning environments such as Virtual Reality (VR). VR environments may aid students' efforts to be active learners through consciously attending to, and reflecting on, critique leveraging reflexivity and novel meaning-making most likely to lead to a conceptual change. This paper employs eleven industrial case-studies to highlight the application of multimodal VR-based teaching and training as a pedagogically rich strategy that may be designed, mapped and visualized through distinct VR-design elements and features. The outcomes of the use cases contribute to discern in-VR multimodal teaching as an emerging discourse that couples system design-based paradigms with embodied, situated and reflective praxis in spatial, emotional and temporal VR learning environments

Modélisation THD d’un Palier Lisse. Comparaison sur les Champs Thermiques entre Modèles 2D et 3D

International audienc

Modélisation Thermohydrodynamique Tridimensionnelle des Paliers Lisses par Eléments finis

International audienc

Thermal Behaviour Analysis of Journal Bearing. Influence of Oil Film Viscosity on the Journal Characteristics

International audienceA numerical procedure is developped in order to analyse the " Tridimensional Thermohydrodynamic " behaviour of a bearing under static loading. The Reynolds equation, the energy equation in the film and the heat transfert equation in the solids are simultaneously solved using a Newton-Raphson procedure and the finite element modelisation. The numerical procedure developped incorporates a cavitation algorithm based on JFO model, which automatically predicts film rupture and reformation in the bearings. In the present study, the obtained results from this model are compared to experimentals results and numericals results from THD 2D model. The evolution of the thermal fields are presented and discussed. The comparisons showed that the THD 3D model with the cavitation algorithm is more performant than THD 2D model

Modélisation thermoélastohydrodynamique tridimensionnelle des paliers de moteurs thermiques (mise en place d'un banc d'essais pour paliers sous conditions sévères)

Les paliers fluides dans les moteurs thermiques sont utilisés pour guider en rotation certains organes (bielle, vilebrequin, ). Les vitesses de rotation imposées à celles-ci associées d'une réduction de leur masse font que les températures présentes dans le contact sont très importantes. Un modèle numérique complet de la lubrification TEHD 3D a donc été développé. Celui-ci décrit l'équation de Reynolds généralisée bidimensionnelle, les équations de l'énergie et de la chaleur tridimensionnelles pour le calcul de la pression, des températures dans le film et les solides. Celles-ci sont résolues par la méthode des éléments finis. La validation du code est effectuée pour un palier soumis à une charge statique. Pour cela, les résultats obtenus sont comparés avec ceux issus d'un modèle TEHD 2D et ceux issus d'une campagne d'essais. Une bonne concordance sur la température est observée entre les résultats issus du modèle TEHD 3D et ceux obtenus expérimentalement. La comparaison entre le modèle 2D et le modèle 3D montre que la prise en compte de l'évacuation axiale de la température est essentielle pour une bonne détermination des caractéristiques thermiques du palier. Le cahier des charges et la description technique du dispositif expérimental "MEGAPASCALE" est présenté. Ce dernier permet de réaliser des essais dans des conditions réelles de fonctionnement. Ainsi des vitesses de rotation de 20000 tr/min et des charges dynamiques de 90 kN pourront être atteintes.The fluid bearing in the thermal engines are used to guide in rotation certain bodies (rod, crankshaft ). High speed associated with the mass reduction of engine bearings induced high temperature for the lubricated contacts. A numerical procedure of TEHD 3D lubrication, based on finite elements method, was developed. This one described two-dimensional Reynolds Generalized equation, three-dimensional energy equation and heat equation for the calculation of the pressure, the temperatures in film and solids. The validation of the TEHD 3D model was carried out for a steady state bearing. The results are compared with a TEHD 2D model and with experimental data. A good agreement on the temperature is observed between the TEHD 3D model and the experimental data. The comparison between the 3D and 2D numerical models showed that taking into account the heat axial evacuation is essential for a good pattern. The functional specifications as well as the technical description of experimental device "MEGAPASCALE" was presented. This one allows tests under high speed (20000 rev/min) and important dynamical loads (90 kN) which correspond to real operating conditions.POITIERS-BU Sciences (861942102) / SudocSudocFranceF

Etude Thermique d’un Palier de Bielle

International audienc

Thermohydrodynamic lubrication analysis for a dynamically loaded journal bearing

International audienceA numerical procedure is developed to analyse the ‘three-dimensional transient thermohydrodynamic (THD)’ behaviour of bearings under dynamic loading. The Reynolds equation, the three-dimensional energy equation in film, and the three-dimensional heat transfer equation in solids are simultaneously solved using a Newton-Raphson procedure and finite-element modelling to resolve the three-dimensional THD problem. The three-dimensional finite-element meshes of the three domains are interconnected and, therefore, the heat flux continuity conditions become implicit. The developed numerical procedure incorporates a cavitation (mass conservation) algorithm on the basis of the JFO (Jacobson, Floberg, and Olsson) model, which automatically predicts film rupture and reformation in the bearings. In order to validate the three-dimensional model, the temperature fields are compared with the temperature fields obtained with a numerical two-dimensional THD model with a parabolic pressure in the axial direction and also with experimental results. Finally, this model is applied to a bearing under sinusoidal loading in which the oil supply is fixed on the housing