On the Aerodynamic-Noise Sources in a Circular Cylinder Coated with Porous Materials

Coating a circular cylinder with porous materials constitutes an effective passive strategy for reducing the flow-induced noise linked to the vortex shedding. Despite the number of investigations in the last decade, the noise-mitigation mechanisms associated with this technique remain unclear. The present research aims to clarify the role played...

3D-printed Perforated Trailing Edges for Broadband Noise Abatement

Turbulent boundary layer trailing-edge noise scattered by a NACA0018 airfoil equipped with 3D printed perforated trailing-edge inserts, i.e. with straight cylindrical channels connecting the two sides of the airfoil, is investigated. The inserts have different permeability in order to assess the effect of this property on broadband noise...

Flexible, printed, Pb-free piezo-composites for haptic feedback systems

While most of the work on piezoelectric composites focuses on methods to reduce the dielectric constant of the composite (for better sensor and energy harvesting performance), for haptic feedback and actuator applications the opposite is desirable. We present here a study of the effect of adding a second ceramic phase (BaTiO3 nanoparticles)...

BiFeO₃ synthesis by conventional solid-state reaction

BiFeO₃ is a multiferroic material with the perovskite structure which is promising for use in sensors and transducers. Single phase production of BiFeO₃ remains a challenge, however. In this study, the optimal calcination temperature to obtain close to single phase powder was determined to be 750°C. The sintering...

Broadband Trailing-Edge Noise Reduction Using Permeable Metal Foams

The generation of deformation damage during fatigue loading in Al-Cu alloy studied by the Doppler Broadening technique

We have investigated the evolution of damage during fatigue loading in Al-Cu 2024-T3 alloys using the positron annihilation Doppler Broadening (DB) technique. This technique enables us to monitor in a non destructive way, at the atomic and vacancy level, the formation of deformation defects and their interaction with solute atoms at selected...