Search Results - "Juniper, Matthew"

Sensitivity and Nonlinearity of Thermoacoustic Oscillations by Juniper, Matthew P, Sujith, R.I

“…Nine decades of rocket engine and gas turbine development have shown that thermoacoustic oscillations are difficult to predict but can usually be eliminated…”
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Combined state and parameter estimation in level-set methods by Yu, Hans, Juniper, Matthew P., Magri, Luca

“…Reduced-order models based on level-set methods are widely used tools to qualitatively capture and track the nonlinear dynamics of an interface. The aim of…”
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Physics-Informed Compressed Sensing for PC-MRI: An Inverse Navier-Stokes Problem by Kontogiannis, Alexandros, Juniper, Matthew P.

“…We formulate a physics-informed compressed sensing (PICS) method for the reconstruction of velocity fields from noisy and sparse phase-contrast magnetic…”
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Azimuthal instabilities in annular combustors: standing and spinning modes by Ghirardo, Giulio, Juniper, Matthew P.

“…This theoretical study investigates spinning and standing modes in azimuthally symmetric annular combustion chambers. Both modes are observed in experiments…”
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Nonlinear thermoacoustics of ducted premixed flames: The influence of perturbation convection speed by Kashinath, Karthik, Hemchandra, Santosh, Juniper, Matthew P.

“…When a premixed flame is placed within a duct, acoustic waves induce velocity perturbations at the flame’s base. These travel down the flame, distorting its…”
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The effect of the flame phase on thermoacoustic instabilities by Ghirardo, Giulio, Juniper, Matthew P., Bothien, Mirko R.

“…This paper concerns the influence of the phase of the heat release response on thermoacoustic systems. We focus on one pair of degenerate azimuthal acoustic…”
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Linear stability and adjoint sensitivity analysis of thermoacoustic networks with premixed flames by Orchini, Alessandro, Juniper, Matthew P.

“…We analyse the linear response of laminar conical premixed flames modelled with the linearised front-track kinematic G-equation. We start by considering the…”
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Nonlinear dynamics of a self-excited thermoacoustic system subjected to acoustic forcing by Balusamy, Saravanan, Li, Larry K.B., Han, Zhiyi, Juniper, Matthew P., Hochgreb, Simone

“…We experimentally study the nonlinear dynamics of a self-excited thermoacoustic system subjected to acoustic forcing. Our aim is to relate these dynamics to…”
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Thermoacoustic stabilization of combustors with gradient-augmented Bayesian optimization and adjoint models by Sengupta, Ushnish, Juniper, Matthew P.

“…Bayesian optimization (BO) is a global optimization algorithm well-suited for multimodal functions that are costly to evaluate, e.g. quantities derived from…”
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Adjoint-based sensitivity analysis of low-order thermoacoustic networks using a wave-based approach by Aguilar, José G., Magri, Luca, Juniper, Matthew P.

“…Strict pollutant emission regulations are pushing gas turbine manufacturers to develop devices that operate in lean conditions, with the downside that…”
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Optimal experiment design with adjoint-accelerated Bayesian inference by Yoko, Matthew, Juniper, Matthew P.

“…We develop and demonstrate a computationally cheap framework to identify optimal experiments for Bayesian inference of physics-based models. We develop the…”
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The structural sensitivity of open shear flows calculated with a local stability analysis by Juniper, Matthew P., Pier, Benoit

“…The structural sensitivity shows where an instability of a fluid flow is most sensitive to changes in internal feedback mechanisms. It is formed from the…”
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Nonlinear hydrodynamic and thermoacoustic oscillations of a bluff-body stabilised turbulent premixed flame by Lee, Chin Yik, Li, Larry Kin Bong, Juniper, Matthew P., Cant, Robert Stewart

“…Turbulent premixed flames often experience thermoacoustic instabilities when the combustion heat release rate is in phase with acoustic pressure fluctuations…”
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Experimental sensitivity analysis of a linearly stable thermoacoustic system via a pulsed forcing technique by Jamieson, Nicholas P., Juniper, Matthew P.

“…In this paper, we present the results of an experimental sensitivity analysis on a vertical electrically heated Rijke tube. We examine the shift in linear…”
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G-equation modelling of thermoacoustic oscillations of partially premixed flames by Semlitsch, Bernhard, Orchini, Alessandro, Dowling, Ann P, Juniper, Matthew P

“…Numerical simulations aid combustor design to avoid and reduce thermoacoustic oscillations. Non-linear heat release rate estimation and its modelling are…”
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State-space realization of a describing function by Ghirardo, Giulio, Ćosić, Bernhard, Juniper, Matthew P., Moeck, Jonas P.

“…The describing function is a powerful tool for characterizing nonlinear dynamical systems in the frequency domain. In some cases, it is the only available…”
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Adjoint algorithms for the Navier–Stokes equations in the low Mach number limit by Chandler, Gary J., Juniper, Matthew P., Nichols, Joseph W., Schmid, Peter J.

“…This paper describes a derivation of the adjoint low Mach number equations and their implementation and validation within a global mode solver. The advantage…”
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Forecasting thermoacoustic instabilities in liquid propellant rocket engines using multimodal Bayesian deep learning by Sengupta, Ushnish, Waxenegger-Wilfing, Günther, Martin, Jan, Hardi, Justin, Juniper, Matthew P.

“…We present a method that combines multiple sensory modalities in a rocket thrust chamber to predict impending thermoacoustic instabilities with uncertainties…”
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Experimental sensitivity analysis via a secondary heat source in an oscillating thermoacoustic system by Jamieson, Nicholas P, Rigas, Georgios, Juniper, Matthew P

“…In this article, we report the results of an experimental sensitivity analysis on a vertical electrically heated Rijke tube. We examine the stability…”
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Adjoint-Based Linear Analysis in Reduced-Order Thermo-Acoustic Models by Magri, Luca, Juniper, Matthew P.

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