Simon Bouley

MicrodB

We address the problem of blind gain and phase calibration of a sensor array from ambient noise. The key motivation is to ease the calibration process by avoiding a complex procedure setup. We show that computing the sample covariance matrix in a diffuse field is sufficient to recover the complex gains. To do so, we formulate a non-convex least-squ...

We address the problem of blind gain and phase calibration of a sensor array from ambient noise. The key motivation is to ease the calibration process by avoiding a complex procedure setup. We show that computing the sample covariance matrix in a diffuse field is sufficient to recover the complex gains. To do so, we formulate a non-convex least-squ...

The rising interest for three-dimensional acoustic imaging requires the improvement of the numerical models describing the propagation between a radiating body and a microphone array. The commonly used free field transfer functions boil down to assume a full acoustic transparency of the radiating object, which, in some cases, may lead to misleading...

In accordance with aeroacoustic analogies, the noise arising from the interaction of an object and a low Mach number flow is likely to be accurately described by the radiation of elementary monopoles, dipoles and quadrupoles. Combined with the diffracting behaviour of the car as a rigid body, three-dimensional source identification in wind tunnel i...

Aeroacoustic signals, as typically returned by recordings of pressure fluctuations generated by rotating machines, often exhibit a strong contribution of broadband components. The separate analysis of the various sources of broadband noise is important from an engineering point of view as they relate to different physical mechanisms. It is yet tech...

Source localization and quantification by an acoustic array of microphones depend to a great extent on an accurate knowledge of the antenna position towards the radiating device. The present work details a methodology to determine the location of the microphones in relation to an object of study, starting from its geometric shape and that of the ar...

As the mining of deep-sea natural deposits is becoming cost competitive compared to similar land-based mining, companies have started to dig into the seabeds to collect minerals. However, the acoustic contribution of this activity in the surrounding environment can be significant. To predict the impact of such noise, the starting point is to locali...

A postprocessing methodology of microphone-array results for accurate source localization and separation is described. A method constrained iterative restoration algorithm with an assumption of uncorrelated sources is used to extract quantitative spectral results for multiple noise sources identified on a wall-mounted finite-span swept and cambered...

The reconstruction of sound sources by using inverse methods is known to be prone to estimation errors due to measurement noise, model mismatch, and poor conditioning of the inverse problem. This paper introduces a solution to map the estimation errors together with the reconstructed sound sources. From a Bayesian perspective, it initializes a Gibb...

The characterization of acoustic sources typically involves the retro-propagation of the acoustic field measured with a microphone array to a mesh of the surface of interest, which amounts to solve an inverse problem. Such an inverse problem is built on the basis of a forward model prone to uncertainties arising from mismatches with the physics of...

The present work deals with the analytical modeling of two aspects of outlet guide vane aeroacoustics in axial-flow fan and compressor rotor-stator stages. The first addressed mechanism is the downstream transmission of rotor noise through the outlet guide vanes, the second one is the sound generation by the impingement of the rotor wakes on the va...

The rotor-stator wake-interaction tonal noise, generated by the impingement of rotor wakes on outlet guide vanes, plays a crucial role in the aerodynamic noise of axial-flow ducted fan stages. The latter are widely used in most aeronautic propulsion and air-conditioning systems. The noise prediction by means of numerical simulations remains expensi...