Transverse combustion instabilities: Acoustic, fluid mechanic, and flame processes

J O'Connor, V Acharya, T Lieuwen - Progress in Energy and Combustion …, 2015 - Elsevier
Thermoacoustic oscillations associated with transverse acoustic modes are routinely
encountered in combustion chambers. While a large literature on this topic exists for rockets …

Adjoint equations in stability analysis

P Luchini, A Bottaro - Annual Review of fluid mechanics, 2014 - annualreviews.org
The objective of this article is to review some developments in the use of adjoint equations in
hydrodynamic stability theory. Adjoint-based sensitivity analysis finds both analytical and …

Wavepackets and trapped acoustic modes in a turbulent jet: coherent structure eduction and global stability

OT Schmidt, A Towne, T Colonius… - Journal of Fluid …, 2017 - cambridge.org
Coherent features of a turbulent Mach 0.9, Reynolds number jet are educed from a high-
fidelity large eddy simulation. Besides the well-known Kelvin–Helmholtz instabilities of the …

Primary instability, sensitivity and active control of flow past two tandem circular cylinders

Z Liu, L Zhou, H Tang, Z Wang, F Zhao, X Ji, H Zhang - Ocean Engineering, 2024 - Elsevier
The tandem two-cylinder configuration is frequently employed in engineering structures. Its
fluid force and vortex shedding are significantly greater than those of widely studied single …

Optimal eddy viscosity for resolvent-based models of coherent structures in turbulent jets

E Pickering, G Rigas, OT Schmidt, D Sipp… - Journal of Fluid …, 2021 - cambridge.org
Response modes computed via linear resolvent analysis of a turbulent mean-flow field have
been shown to qualitatively capture characteristics of the observed turbulent coherent …

Coherent structures in a swirl injector at Re= 4800 by nonlinear simulations and linear global modes

O Tammisola, MP Juniper - Journal of Fluid Mechanics, 2016 - cambridge.org
The large-scale coherent motions in a realistic swirl fuel-injector geometry are analysed by
direct numerical simulations (DNS), proper orthogonal decomposition (POD), and linear …

Sensitivity-aided active control of flow past twin cylinders

L Zhou, H Li, KT Tim, X He, GYC Maceda… - International Journal of …, 2023 - Elsevier
The flow-induced vibration (FIV) of twin structures always experiences significantly larger
vibration amplitude than that of a single one, which causes severe structural safety …

Single-and double-helix vortex breakdown as two dominant global modes in turbulent swirling jet flow

M Vanierschot, JS Müller, M Sieber… - Journal of Fluid …, 2020 - cambridge.org
In this paper, we study the shape and dynamics of helical coherent structures found in the
flow field of an annular swirling jet undergoing vortex breakdown. The flow field is studied by …

Prediction of the hub vortex instability in a wind turbine wake: stability analysis with eddy-viscosity models calibrated on wind tunnel data

F Viola, GV Iungo, S Camarri, F Porté-Agel… - Journal of Fluid …, 2014 - cambridge.org
The instability of the hub vortex observed in wind turbine wakes has recently been studied
by Iungo et al.(J. Fluid Mech., vol. 737, 2013, pp. 499–526) via local stability analysis of the …

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 …