Adjoint methods as design tools in thermoacoustics

L Magri - Applied Mechanics Reviews, 2019 - asmedigitalcollection.asme.org
In a thermoacoustic system, such as a flame in a combustor, heat release oscillations couple
with acoustic pressure oscillations. If the heat release is sufficiently in phase with the …

Perturbation theory of nonlinear, non-self-adjoint eigenvalue problems: simple eigenvalues

GA Mensah, A Orchini, JP Moeck - Journal of Sound and Vibration, 2020 - Elsevier
The study of the vibrational modes and stability of a given physical system is strongly tied to
the efficient numerical evaluation of its eigenvalues. The operators governing the …

Thermoacoustic modes of intrinsic and acoustic origin and their interplay with exceptional points

A Orchini, CF Silva, GA Mensah, JP Moeck - Combustion and Flame, 2020 - Elsevier
We propose a general classification of all the modes of a given thermoacoustic system into
two sets: one of acoustic origin and one of intrinsic thermoacoustic (ITA) origin. To do this …

Low-order modeling to investigate clusters of intrinsic thermoacoustic modes in annular combustors

GJJ Fournier, M Haeringer… - … of Engineering for …, 2021 - asmedigitalcollection.asme.org
The intrinsic thermoacoustic (ITA) feedbackloop constitutes a coupling between flow, flame
and acoustics that does not involve the natural acoustic modes of the system. One recent …

Intrinsic thermoacoustic modes in an annular combustion chamber

PE Buschmann, GA Mensah, JP Moeck - Combustion and Flame, 2020 - Elsevier
Thermoacoustic instabilities originate from the interaction of unsteady heat release rate
associated with flames and the acoustic modes of a combustor. A feedback loop not …

A state-space formulation of a discontinuous Galerkin method for thermoacoustic stability analysis

M Meindl, A Albayrak, W Polifke - Journal of Sound and Vibration, 2020 - Elsevier
A hybrid approach for thermoacoustic stability analysis is formulated in a state-space
framework. The approach distinguishes between regions of the computational domain with …

Thermoacoustic spectrum of a swirled premixed combustor with partially reflecting boundaries

KJ Yong, M Meindl, W Polifke… - … of Engineering for …, 2020 - asmedigitalcollection.asme.org
This study investigates the effect of partial acoustic reflection at inlet or outlet of a combustor
on thermoacoustic stability. Parametric maps of the thermoacoustic spectrum are utilized for …

Adjoint-based calculation of parametric thermoacoustic maps of an industrial combustion chamber

CF Silva, L Prieto, M Ancharek… - … for Gas Turbines …, 2021 - asmedigitalcollection.asme.org
The aim of this study is to efficiently calculate parametric thermoacoustic maps of typical
combustion chambers. Two configurations are considered: an academic configuration …

Low-Order Modeling to Investigate Clusters of ITA Modes in Annular Combustors

GJJ Fournier, M Haeringer… - … Expo: Power for …, 2020 - asmedigitalcollection.asme.org
The intrinsic thermoacoustic (ITA) feedbackloop constitutes a coupling between flow, flame
and acoustics that does not involve the natural acoustic modes of the system. One recent …