Published in Scientific Reports
The use of high-speed cameras permits to visualize, analyze or study physical phenomena at both their time and spatial scales. Mixing high-speed imaging with coherent imaging allows recording and retrieving the optical path difference and this opens the way for investigating a broad variety of scientific challenges in biology, medicine, material sc...
The quality of ultrasound images of welds is highly penalized by the dendritic structure of the material that forms during cooling. The image of a flaw is all the more degraded as a reliable description of such a medium is most of the time not possible, due to the poor knowledge on the weld at time of inspection. In a previous work, we demonstrated...
This work propose a simple, non-destructive and non-intrusive characterization technique, applied to lead acid batteries for battery monitoring during operation. It consists in installing two piezoelectric transducers on the surface of a battery and studying the transport of ultrasonic acoustic waves through the battery. The acoustic signal transmi...
In the present paper, large eddy simulations are performed to study two different mechanisms of Fan/OGV broadband noise: airfoil self-noise and turbulence interaction noise. Firstly, the current study focuses on the prediction of airfoil self-noise from a thin plate with a sharp trailing edge and a chord-based Reynolds number of the order of 1e6. T...
This paper explores a family of generalized sweeping preconditionners for Helmholtz problems with non-overlapping checkerboard partition of the computational domain. The domain decomposition procedure relies on high-order transmission conditions and cross-point treatments, which cannot scale without an efficient preconditioning technique when the n...
Ultrasonic inspection of coarse-grained steels is a common challenge in various industrial fields. This task is often difficult because of acoustic scattering that creates structural noise in the ultrasonic signals and images. This drives inspections using low-frequency probes at the cost of a lower resolution of standard delay and sum (DAS) imagin...
International audience
International audience
The internal geometry of a wind instrument can be estimated from acoustic measurements. For woodwind instruments, it implies to characterize the inner shape (bore) but also the side holes (dimensions and location). In this study, the geometric parameters are recovered by a gradient-based optimization process, which minimizes the deviation between s...
Woodwind tonehole’s linear behavior is characterized by two complex quantities: the series and shunt acoustic impedances. A method to determine experimentally these two quantities is presented. It is based on two input impedance measurements. The method can be applied to clarinet-like instruments.The robustness of the method proposed is explored nu...
