55 citations · 294 across the 19 of their papers we have counts for
21 papers
Whistling of turbulent cavity flows: Self-consistent predictions with the linearized compressible Navier-Stokes equations
Nikolaos Bozikis, Dilara Özev, Nicolas Noiray
A self-consistent saturation model for the prediction of aeroacoustic limit cycles emerging in turbulent low-Mach cavity flows (Re=O(10^5), M\simeq 0.2) is proposed. It predicts th…
Hydrogen reaction rate modeling based on convolutional neural network for large eddy simulation
Quentin Malé, Corentin J Lapeyre, Nicolas Noiray
This paper establishes a data-driven modeling framework for lean Hydrogen (H2)-air reaction rates for the Large Eddy Simulation (LES) of turbulent reactive flows. This is particula…
A real-time digital twin of azimuthal thermoacoustic instabilities
Andrea Nóvoa, Nicolas Noiray, James R. Dawson +1
When they occur, azimuthal thermoacoustic oscillations can detrimentally affect the safe operation of gas turbines and aeroengines. We develop a real-time digital twin of azimuthal…
Synchronization-based lossless non-reciprocal scattering
Tiemo Pedergnana, Abel Faure-Beaulieu, Romain Fleury +1
Breaking the reciprocity of wave propagation is a problem of fundamental interest, and a mucht-sought functionality in practical applications, both in photonics and phononics. Alth…
Smooth transformations and ruling out closed orbits in planar systems
Tiemo Pedergnana, Nicolas Noiray
This work deals with planar dynamical systems with and without noise. In the first part, we seek to gain a refined understanding of such systems by studying their differential-geom…
Numerical study of ignition and combustion of hydrogen-enriched methane in a sequential combustor
Matteo Impagnatiello, Quentin Malé, Nicolas Noiray
Ignition and combustion behavior in the second stage of a sequential combustor are investigated numerically at atmospheric pressure for pure CH4 fueling and for a CH4/H2 fuel blend…
Exact potentials in multivariate Langevin equations
Tiemo Pedergnana, Nicolas Noiray
Systems governed by a multivariate Langevin equation featuring an exact potential exhibit straightforward dynamics but are often difficult to recognize because, after a general coo…
Superradiant Scattering from Nonlinear Wave-Mode Coupling
Tiemo Pedergnana, Nicolas Noiray
Waves scattered at a self-oscillating mode can exhibit superradiance, or net amplification of an external harmonic excitation. This exotic behavior, arising from the nonlinear coup…
Steady State Statistics of Emergent Patterns in a Ring of Oscillators
Tiemo Pedergnana, Nicolas Noiray
Networks of coupled nonlinear oscillators model a broad class of physical, chemical and biological systems. Understanding emergent patterns in such networks is an ongoing effort wi…
Dynamics of azimuthal thermoacoustic modes in imperfectly symmetric annular geometries
Thomas Indlekofer, Abel Faure-Beaulieu, James R. Dawson +1
Using a nominally symmetric annular combustor, we present experimental evidence of a predicted spontaneous symmetry breaking and an unexpected explicit symmetry breaking in the nei…
Coupling-Induced Instability in a Ring of Thermoacoustic Oscillators
Tiemo Pedergnana, Nicolas Noiray
Thermoacoustic instabilities in can-annular combustors of stationary gas turbines lead to unstable Bloch modes which appear as rotating acoustic pressure waves along the turbine an…
Modeling the nonlinear aeroacoustic response of a harmonically forced side branch aperture under turbulent grazing flow
Tiemo Pedergnana, Claire Bourquard, Abel Faure-Beaulieu +1
Hydrodynamic modes in the turbulent mixing layer over a cavity can constructively interact with the acoustic modes of that cavity and lead to aeroacoustic instabilities. The result…
Symmetry breaking of azimuthal waves: Slow-flow dynamics on the Bloch Sphere
Abel Faure Beaulieu, Nicolas Noiray
Depending on the reflectional and rotational symmetries of annular combustors for aeroengines and gas turbines, self-sustained azimuthal thermoacoustic eigenmodes can be standing,…
Stabilization of acoustic modes using Helmholtz and Quarter-Wave resonators tuned at exceptional points
Claire Bourquard, Nicolas Noiray
Acoustic dampers are efficient and cost-effective means for suppressing thermoacoustic instabilities in combustion chambers. However, their design and the choice of their purging a…
Bifurcation Dodge: Avoidance of a Thermoacoustic Instability under Transient Operation
Giacomo Bonciolini, Nicolas Noiray
Varying one of the governing parameters of a dynamical system may lead to a critical transition, where the new stable state is undesirable. In some cases, there is only a limited r…
Combustion regimes in sequential combustors: Flame propagation and autoignition at elevated temperature and pressure
Oliver Schulz, Nicolas Noiray
This numerical study investigates the combustion modes in the second stage of a sequential combustor at atmospheric and high pressure. The sequential burner (SB) features a mixing…
Processing time-series of randomly forced self-oscillators: the example of beer bottle whistling
E. Boujo, C. Bourquard, Y. Xiong +1
We present a model-based, output-only parameter identification method for self-sustained oscillators forced by dynamic noise, which we illustrate experimentally with an aeroacousti…
Effect of wall thermal inertia upon transient thermoacoustic dynamics of a swirl-stabilized flame
Giacomo Bonciolini, Dominik Ebi, Ulrich Doll +2
This paper shows the importance of considering the thermal state of a combustor to investigate or predict its thermoacoustic stability. This aspect is often neglected or regarded a…
Experiments and modelling of rate-dependent transition delay in a stochastic subcritical bifurcation
Giacomo Bonciolini, Dominik Ebi, Edouard Boujo +1
Complex systems exhibiting critical transitions when one of their governing parameters varies are ubiquitous in nature and in engineering applications. Despite a vast literature fo…
Output-only parameter identification of a colored-noise-driven Van der Pol oscillator -- Thermoacoustic instabilities as an example
Giacomo Bonciolini, Edouard Boujo, Nicolas Noiray
The problem of output-only parameter identification for nonlinear oscillators forced by colored noise is considered. In this context, it is often assumed that the forcing noise is…
Robust identification of harmonic oscillator parameters using the adjoint Fokker-Planck equation
Edouard Boujo, Nicolas Noiray
We present a model-based output-only method for identifying from time series the parameters governing the dynamics of stochastically forced oscillators. In this context, suitable m…