Energy Efficiency Optimization of Superhydrophobic Surfaces for Enhanced Condensation Heat Transfer

The process of droplets jumping, against adhesive forces, from a solid surface upon coalescence has been studied in detail using experimentally-validated CFD modelling. Both Lattice Boltzmann and Volume of Fluid methods have been used to evaluate different kinematic conditions of coalescence inducing a jump velocity. Design of experiment techniques were used to establish near-optimal initial process parameters around which to focus the study. This multidisciplinary approach allows us to evaluate the jumping phenomenon for super-hydrophobic surfaces for which several input parameters may be varied, so as to improve the heat transfer exchange rate on the surface during condensation. Reliable conditions were found to occur for droplets within initial radius range of r=20-40 μm and static contact angle θs~160º. Moreover, the jumping phenomenon was observed for droplets with initial radius of up to 500 μm. Our study also shows that a critical contact angle for droplets to jump upon coalescence is θc~140º

Analysis of surface roughness morphology with TRIZ methodology in automotive electrical contacts: Design against third body fretting-corrosion

Electrical connectors for motor vehicles are essential for the safe and efficient operation of a vehicle. However, their durability is limited by fretting induced corrosion. This type of surface damage is observed between two interconnected surfaces exposed to vibration and temperature variations. Such conditions occur during normal vehicle operation and cause two parts of an electrical contact to move at high frequency and with a small amplitude of movement relative to each other. This damages both surfaces, creates wear particles and then oxidizes them in the air. This causes an oxide layer to form at the interface, isolating the two surfaces and increasing the electrical resistance, resulting in contact failure. This study shows how the service life of electrical contacts can be extended by a surface design approach that controls the metal interface and ensures low contact resistance. The approach combines surface morphology with the progressive process of interfacial oxidation. A strong relationship between surface roughness and electrical contact resistance was observed and is elucidated in this study. Theory of Inventive Problems Solving (TRIZ) was used to identify surface texturing as a viable option to increase durability of automotive electrical connectors

Influence of Cutting Conditions in the Topography of Texturized Surfaces on Aluminium 7075 Plates Produced by Robot Machining

International audienc

Information-Rich Manufacturing Metrology

Part 4: Digital Technologies and Industry 4.0 ApplicationsInternational audienceInformation-rich metrology (IRM) is a new term that refers to an approach, where the conventional paradigm of measurement is transcended, thanks to the introduction and active role of multiple novel sources of information. The overarching goal of IRM is to encompass and homogenise all those measurement scenarios where information available from heterogeneous sources, for example, from the object being measured, the manufacturing process that was used to fabricate it, the workings of the measurement instrument itself, as well as from any previous measurements carried with any other instrument, is gathered and somewhat incorporated with an active role into the measurement pipeline in order to ultimately achieve a higher-quality measurement result (better metrological performance, shorter measurement times, smaller consumption of resources). Examples of IRM in action in precision and additive manufacturing will be presented, including the measurement of form and texture