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Distributed heat release effects on entropy generation by premixed, laminar flames Int. J. Spray Combust. Dyn. (IF 1.6) Pub Date : 2023-05-10 Akbar Laksana, Parth Patki, Tony John, Vishal Acharya, Timothy Lieuwen
This article studies the generation of entropy disturbances by laminar premixed flames. The total entropy generation equals the integrated ratio of the local heat release rate and the local tempera...
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Experimental study of a slit in the presence of a bias flow under medium- and high-level acoustic excitations Int. J. Spray Combust. Dyn. (IF 1.6) Pub Date : 2023-04-11 Alessia Aulitto, Avraham Hirschberg, Ines Lopez Arteaga, Vertika Saxena
This work presents an experimental investigation of the acoustic properties of a slit in the presence of a bias flow under moderate- and high-acoustic excitations. Impedance tube experiments are di...
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Incompressible versus compressible large eddy simulation for the identification of premixed flame dynamics Int. J. Spray Combust. Dyn. (IF 1.6) Pub Date : 2023-03-17 Alexander J Eder, Camilo F Silva, Matthias Haeringer, Johannes Kuhlmann, Wolfgang Polifke
The present work compares the respective advantages and disadvantages of compressible and incompressible computational fluid dynamics (CFD) formulations when used for the estimation of the acoustic...
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A direct numerical simulation analysis of localised forced ignition in turbulent slot jets of CH4/CO2 blends Int. J. Spray Combust. Dyn. (IF 1.6) Pub Date : 2023-03-17 Charles Turquand d’Auzay, Nilanjan Chakraborty
The early stages of flame evolution following successful localised forced ignition of different CH4/CO2 blends in a slot jet configuration have been analysed using three-dimensional direct numerica...
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Stability and structure of lean swirling spray flames with various degrees of prevaporization Int. J. Spray Combust. Dyn. (IF 1.6) Pub Date : 2023-03-15 Jiayi Wang, Pedro M. de Oliveira, Rohit Singh Pathania, Ingrid El Helou, Epaminondas Mastorakos
Achieving full premixing and complete evaporation in lean prevaporized premixed combustors is challenging as it depends on the spray injector characteristics, prevaporisation strategy, and flow con...
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Flame Transfer Functions of the Lean Burnout Zone of an RQL Combustion Chamber - Dynamic Response to Primary Zone and Mixing Port Velocity Fluctuations Int. J. Spray Combust. Dyn. (IF 1.6) Pub Date : 2023-03-07 Julian Renner, Martin March, Thuy An Do, Moritz Merk, Christoph Hirsch, Thomas Sattelmayer
This article describes an experimental investigation of thermoacoustic flame transfer functions of the lean burnout zone of an rich–quench–lean combustion chamber. With spatial separation of the ri...
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Effect of geometrical parameters and use of porous material in a Helmholtz resonator on suppression of thermo-acoustic instabilities Int. J. Spray Combust. Dyn. (IF 1.6) Pub Date : 2023-03-06 Nilaj N. Deshmukh, Afzal Ansari, Sharvil Degwekar, Benson Paul, Rohit Unnikrishnan
Thermo-acoustic instabilities are mainly formed due to in-phase superposition of non-uniform heat release and pressure variation in the combustors of gas turbines, rocket engines and other acoustic...
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E-POD investigations of turbulent premixed flame dynamics approaching lean blow-out conditions Int. J. Spray Combust. Dyn. (IF 1.6) Pub Date : 2023-02-15 Roberto Meloni, Nicola Chiarizia, Pier Carlo Nassini, Antonio Andreini
Thanks to the continuous computational power increase, the use of high-fidelity computational fluid dynamics (CFD) simulations is nowadays customary, especially in the gas turbines design process. ...
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Inhibiting the onset of thermoacoustic instability through targeted control of critical regions Int. J. Spray Combust. Dyn. (IF 1.6) Pub Date : 2023-02-03 Manikandan Raghunathan, Nitin Babu George, Vishnu R. Unni, Jürgen Kurths, Elena Surovyatkina, R. I. Sujith
This experimental study investigates the dynamical transition from stable operation to thermoacoustic instability in a turbulent bluff-body stabilised dump combustor. We conduct experiments to acqu...
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Spray characterization of boron-loaded slurry fuels using high-speed imaging technique Int. J. Spray Combust. Dyn. (IF 1.6) Pub Date : 2023-02-01 P. Prabhudeva, Pawan Kumar Ojha, Srinibas Karmakar
The characterization of atomized spray in terms of its structure, break-up, and droplet morphology is crucial to analyze an engine's performance. Therefore, in this study, the spray characteristics...
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Forecasting thermoacoustic instabilities in liquid propellant rocket engines using multimodal Bayesian deep learning Int. J. Spray Combust. Dyn. (IF 1.6) Pub Date : 2022-12-06 Ushnish Sengupta, Günther Waxenegger-Wilfing, Jan Martin, Justin Hardi, Matthew P. Juniper
We present a method that combines multiple sensory modalities in a rocket thrust chamber to predict impending thermoacoustic instabilities with uncertainties. This is accomplished by training an au...
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Flame dynamics in the lean burnout zone of an RQL combustion chamber - response to primary zone velocity fluctuations Int. J. Spray Combust. Dyn. (IF 1.6) Pub Date : 2022-09-28 Julian Renner, Martin March, Christoph Hirsch, Thomas Sattelmayer
This study focuses on elucidating the flame dynamics of the lean burnout zone of an Rich-Quench-Lean (RQL) combustion chamber. With a new experimental approach of spatially separating the rich prim...
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Numerical investigation of the response of turbulent swirl non-premixed flames to air flow oscillations Int. J. Spray Combust. Dyn. (IF 1.6) Pub Date : 2022-08-29 Andrea Giusti, Huangwei Zhang, Anna-Maria Kypraiou, Patton M. Allison, Epaminondas Mastorakos
The response of swirl non-premixed flames to air flow oscillations is studied using Large-Eddy Simulation (LES) and the Conditional Moment Closure (CMC) combustion model, focusing on the physical m...
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Designing variable reflection coefficient for upstream and downstream terminations to study their effect on flame thermoacoustics Int. J. Spray Combust. Dyn. (IF 1.6) Pub Date : 2022-07-02 Vertika Saxena, Viktor Kornilov, Ines Lopez Arteaga, LPH De Goey
In this paper, the design, construction and results of experiments performed on a generic combustion system are presented. The setup is supplemented by various weakly frequency-dependent variable r...
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Thermoacoustic stabilization of combustors with gradient-augmented Bayesian optimization and adjoint models Int. J. Spray Combust. Dyn. (IF 1.6) Pub Date : 2022-06-23 Ushnish Sengupta, Matthew P. Juniper
Bayesian optimization (BO) is a global optimization algorithm well-suited for multimodal functions that are costly to evaluate, e.g. quantities derived from computationally expensive simulations. R...
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The flame displacement speed: A key quantity for turbulent combustion and combustion instability Int. J. Spray Combust. Dyn. (IF 1.6) Pub Date : 2022-06-06 Paul Palies
Future combustion power and propulsion systems may operate in premixed regime enabling reduced fuel burn and reduced pollutant emissions. The turbulent premixed regime in those future combustion sy...
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Autoignition flame transfer matrix: Analytical model versus large eddy simulations Int. J. Spray Combust. Dyn. (IF 1.6) Pub Date : 2022-06-06 Francesco Gant, Alexis Cuquel, Mirko R. Bothien
Modern gas turbines need to fulfil increasingly stringent emission targets on the one hand and exhibit outstanding operational and fuel flexibility on the other. Ansaldo Energia GT26 and GT36 gas t...
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Large-eddy simulation and challenges for projection-based reduced-order modeling of a gas turbine model combustor Int. J. Spray Combust. Dyn. (IF 1.6) Pub Date : 2022-06-06 Nicholas Arnold-Medabalimi, Cheng Huang, Karthik Duraisamy
Computationally efficient modeling of gas turbine combustion is challenging due to the chaotic multi-scale physics and the complex non-linear interactions between acoustic, hydrodynamic, and chemic...
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Atomization characteristics of a bluff body-assisted sonic twin-fluid atomizer Int. J. Spray Combust. Dyn. (IF 1.6) Pub Date : 2022-05-30 Raghav Sikka, Knut Vågsæther, Dag Bjerketvedt, Joachim Lundberg
This study examines the gas dynamic effect and atomization behaviour of the sonic bluff body-assisted twin-fluid atomizer with three distinct geometry configurations based on cone distances (Lc) as...
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Nonlinear flame response modelling by a parsimonious set of ordinary differential equations Int. J. Spray Combust. Dyn. (IF 1.6) Pub Date : 2022-05-18 Gregor Doehner, Matthias Haeringer, Camilo F. Silva
In this work we present a parsimonious set of ordinary differential equations (ODEs) that describes with satisfactory precision the linear and non-linear dynamics of a typical laminar premixed flam...
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Proceedings of the Symposium on Thermoacoustics in Combustion Int. J. Spray Combust. Dyn. (IF 1.6) Pub Date : 2022-05-11 Mirko Bothien
The Symposium on Thermoacoustics in Combustion (SoTiC 2021) took place virtually from September 6-10, 2021. The organization of this year’s symposium was a collaboration of Mirko Bothien and Luca Magri, at that time Fellows of the Institute for Advanced Studies, with the Thermodynamics Institute, supported by a Scientific and an Organizing Committee and with contributions from the EU Training Networks
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Iterative solvers for the thermoacoustic nonlinear eigenvalue problem and their convergence properties Int. J. Spray Combust. Dyn. (IF 1.6) Pub Date : 2022-05-09 Georg A. Mensah, Philip E. Buschmann, Alessandro Orchini
The spectrum of the thermoacoustic operator is governed by a nonlinear eigenvalue problem. A few different strategies have been proposed by the thermoacoustic community to tackle it and identify the frequencies and growth rates of thermoacoustic eigenmodes. These strategies typically require the use of iterative algorithms, which need an initial guess and are not necessarily guaranteed to converge
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Spray response on a model prefilmer under unsteady airflows of various frequencies Int. J. Spray Combust. Dyn. (IF 1.6) Pub Date : 2022-05-09 Thomas Christou, Björn Stelzner, Nikolaos Zarzalis
An appealing concept for jet engine combustors is the Lean Premixed Prevaporized (LPP) combustor, which operates at high pressures. The low NOx emissions achieved by lean combustion are one of the ...
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Robust combustor design based on flame transfer function modification Int. J. Spray Combust. Dyn. (IF 1.6) Pub Date : 2022-04-28 Jakob G. R. von Saldern, Johann Moritz Reumschüssel, Jan Paul Beuth, Christian Oliver Paschereit, Kilian Oberleithner
Operation under stable conditions is an important prerequisite for gas turbine safety. While recent studies have focused primarily on acoustic design to avoid thermoacoustic instabilities, in the present study we shift the focus to improving stability margins by flame transfer function (FTF) modification. The flame transfer function of premixed flames is affected by various mechanisms such as variations
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Impact of shear-coaxial injector hydrodynamics on high-frequency combustion instabilities in a representative cryogenic rocket engine Int. J. Spray Combust. Dyn. (IF 1.6) Pub Date : 2022-04-27 Wolfgang Armbruster, Justin Hardi, Michael Oschwald
The excitation mechanism of a thermoacoustic instability in a 42-element research rocket thrust chamber with representative operating conditions with respect to European cryogenic rocket engines is investigated in detail. From previous research it was known that the chamber 1T mode can be excited by persistent heat release rate oscillations which are modulated by the resonant modes of the liquid oxygen
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Analytical modelling of flame transfer functions for technically premixed flames Int. J. Spray Combust. Dyn. (IF 1.6) Pub Date : 2022-04-21 Fernando Biagioli, Alessandro Innocenti, Ammar Lamraoui, Khawar J Syed
The linear response to harmonic acoustic excitation of the total heat release rate in technically premixed flames (Flame Transfer Function, FTF) is studied in case of an ideal swirl burner. The analysis is based on the linearization of the production rate for the mean reaction progress variable modelled with a turbulent flame speed closure. Three main components of the FTF are identified which are
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Stability criteria of two-port networks, application to thermo-acoustic systems Int. J. Spray Combust. Dyn. (IF 1.6) Pub Date : 2022-04-12 Mohammad Kojourimanesh, Viktor Kornilov, Ines Lopez Arteaga, Philip de Goey
System theory methods are developed and applied to introduce a new analysis methodology based on the stability criteria of active two-ports, to the problem of thermo-acoustic instability in a combustion appliance. The analogy between thermo-acoustics of combustion and small-signal operation of microwave amplifiers is utilized. Notions of unconditional and conditional stabilities of an (active) two-port
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Comparison of the flame dynamics of a premixed dual fuel burner for kerosene and natural gas Int. J. Spray Combust. Dyn. (IF 1.6) Pub Date : 2022-04-12 Jan Kaufmann, Manuel Vogel, Jannes Papenbrock, Thomas Sattelmayer
In this study, the flame dynamics of swirl stabilized lean premixed combustion is investigated for kerosene and natural gas operation. A natural gas swirl burner is retrofitted with a twin-fluid nozzle to allow performing all experiments with the identical burner hardware. The mixture preparation complexity is stepwise increased from perfectly premixed natural gas to technically premixed natural gas
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Response of spray number density and evaporation rate to velocity oscillations Int. J. Spray Combust. Dyn. (IF 1.6) Pub Date : 2022-03-31 Sagar Kulkarni, Camilo F. Silva, Wolfgang Polifke
A theoretical investigation of the effect of gas velocity oscillations on droplet number density and evaporation rate is presented. Oscillations in gas velocity cause a number density wave, i.e. an inhomogeneous, unsteady variation of droplet concentration. The number density wave, as it propagates downstream at the mean flow speed, causes modulation of the local evaporation rate, creating a vapour
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Observation of reactive shear layer modulation associated with high-frequency transverse thermoacoustic oscillations in a gas turbine reheat combustor experiment Int. J. Spray Combust. Dyn. (IF 1.6) Pub Date : 2022-03-31 Jonathan McClure, Frederik M. Berger, Michael Bertsch, Bruno Schuermans, Thomas Sattelmayer
This paper presents the investigation of high-frequency thermoacoustic oscillations and associated flame dynamics in an experimental gas turbine reheat combustor at atmospheric pressure. Examination of dynamic pressure measurements reveals bursts of high-frequency periodic oscillations which appear randomly amidst stochastic fluctuations in the reheat combustor. Analysis of the flame dynamics during
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On the convective wave equation for the investigation of combustor stability using FEM-methods Int. J. Spray Combust. Dyn. (IF 1.6) Pub Date : 2022-03-23 Gerrit Heilmann, Thomas Sattelmayer
Solving the Helmholtz equation with spatially resolved finite element method (FEM) approaches is a well-established and cost-efficient methodology to numerically predict thermoacoustic instabilities. With the implied zero Mach number assumption all interaction mechanisms between acoustics and the mean flow velocity including the advection of acoustic waves are neglected. Incorporating these mechanisms
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Hybrid CFD/low-order modeling of thermoacoustic limit cycle oscillations in can-annular configurations Int. J. Spray Combust. Dyn. (IF 1.6) Pub Date : 2022-03-23 Matthias Haeringer, Wolfgang Polifke
We propose a hybrid strategy for modeling non-linear thermoacoustic phenomena, e.g. limit-cycle (LC) oscillations, in can-annular combustion systems. The suggested model structure comprises a compressible CFD simulation limited to the burner/flame zone of one single can, coupled to a low-order model (LOM) representing the remaining combustor. In order to employ the suggested strategy for modeling non-linear
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Study on cyclic variation rate of fuel flow in the nozzle during fuel injection Int. J. Spray Combust. Dyn. (IF 1.6) Pub Date : 2021-12-01 Wen Hua, Zhang Xin-yu, Jiang Yu-long, Zhao Ling-yao
The fuel flow pattern in the fuel injection nozzle of diesel engine is a complex and changeable phenomenon, which is easily affected by various factors, bringing the differences of flow patterns between multiple injection cycles. To solve the above problem, a visual experimental platform of fuel injection nozzle was built, in which the 100 injection cycles of diesel engine on the same working condition
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Thermal explosion characteristics of a combustible gas containing fuel droplets Int. J. Spray Combust. Dyn. (IF 1.6) Pub Date : 2021-12-01 Saad A. El-Sayed
This paper investigated the critical ignition conditions of combustible gas containing liquid fuel droplets. The analysis is done based on the criteria of the thermal explosion theory. It includes analytical and numerical solutions of modeling equations of fuel droplets heating and evaporation by convection and radiation from the surrounding reactive hot gas. The exothermic reaction is usually modeled
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Development of a wall jet model dedicated to 1D combustion modelling for CI engines Int. J. Spray Combust. Dyn. (IF 1.6) Pub Date : 2021-12-01 Alejandro Aljure Osorio, Xavier Tauzia, Alain Maiboom
Diesel engines are becoming smaller as technology advances, which means that the fuel spray (or jet) interacts with the cylinder walls before combustion starts. Most fuel injection 1D models (especially for diesel fuel) do not consider this interaction. Therefore, a wall-jet sub-model was created on an Eulerian 1D diesel spray model. It was calibrated using data from the literature and validated with
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Interaction of equivalence ratio fluctuations and flow fluctuations in acoustically forced swirl flames Int. J. Spray Combust. Dyn. (IF 1.6) Pub Date : 2021-07-05 Vincent Kather, Finn Lückoff, Christian O. Paschereit, Kilian Oberleithner
The generation and turbulent transport of temporal equivalence ratio fluctuations in a swirl combustor are experimentally investigated and compared to a one-dimensional transport model. These fluctuations are generated by acoustic perturbations at the fuel injector and play a crucial role in the feedback loop leading to thermoacoustic instabilities. The focus of this investigation lies on the interplay
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Numerical prediction of the ignition probability of a lean spray burner Int. J. Spray Combust. Dyn. (IF 1.6) Pub Date : 2021-06-29 Lorenzo Palanti, Antonio Andreini, Bruno Facchini
The optimization of the igniter position is a critical issue in modern aviation gas turbines since it can help to minimize the amount of energy required for ignition and to guarantee a fast relight in case of flameout. From a numerical perspective, several spark discharges should be simulated for each spark position, to account for different realizations due to time-dependent turbulent motions. Unfortunately
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Low-order modeling of high-altitude relight of jet engine combustors Int. J. Spray Combust. Dyn. (IF 1.6) Pub Date : 2021-06-09 Pedro M de Oliveira, Michael P Sitte, Marco Zedda, Andrea Giusti, Epaminondas Mastorakos
A physics-based, low-order ignition model is used to assess the ignition performance of a kerosene-fueled gas-turbine combustor under high-altitude relight conditions. The ignition model used in this study is based on the motion of virtual flame particles and their extinction according to a Karlovitz number criterion, and a stochastic procedure is used to account for the effects of spray polydispersity
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Experimental investigation on spray characteristics of Jet A-1 and alternative aviation fuels Int. J. Spray Combust. Dyn. (IF 1.6) Pub Date : 2021-06-02 Manish Kumar, Srinibas Karmakar, Sonu Kumar, Saptarshi Basu
Potential alternative fuels that can mitigate environmental pollution from gas turbine engines (due to steep growth in the aviation sector globally) are getting significant attention. Spray behavior plays a significant role in influencing the combustion performance of such alternative fuels. In the present study, spray characteristics of Kerosene-based fuel (Jet A-1) and alternative aviation fuels
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Polydisperse spray flame ignition by a pulsed heat flux Int. J. Spray Combust. Dyn. (IF 1.6) Pub Date : 2021-05-31 G Kats, JB Greenberg
A mathematical analysis of the ignition of a polydisperse spray/air mixture by an infinite surface heated in a pulsed manner is presented. In contrast to previous work in the literature, the entire history of the ignition process is accounted for starting from the flame-embryo progenitor stage, through the thermal runaway stage to the final flame propagation stage. For tractability at the current stage
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The effects of ring-shaped porous inert media on equivalence ratio oscillations in a self-excited thermoacoustic instability Int. J. Spray Combust. Dyn. (IF 1.6) Pub Date : 2021-05-27 Cody Dowd, Joseph Meadows
Gas turbine operation increasingly relies on lean premixed (LPM) combustion to reduce harmful emissions, which is susceptible to thermoacoustic instabilities. Most combustion systems are technically premixed and exhibit a degree of equivalence ratio inhomogeneity. Thermoacoustic pressure oscillations can couple with the heat release oscillations through the generation of equivalence ratio fluctuations
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Erratum to “impact of burner plenum acoustics on the sound emission of a turbulent lean premixed open flame” Int. J. Spray Combust. Dyn. (IF 1.6) Pub Date : 2021-05-25
Herff S, Pausch K, Nawroth H, et al. Impact of burner plenum acoustics on the sound emission of a turbulent lean premixed open flame. International Journal of Spray and Combustion Dynamics 2020; 12: 1–20. doi: 10.1177/1756827720956906
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Impact of burner plenum acoustics on the sound emission of a turbulent lean premixed open flame Int. J. Spray Combust. Dyn. (IF 1.6) Pub Date : 2020-09-23 S Herff, K Pausch, H Nawroth, S Schlimpert, CO Paschereit, W Schröder
The acoustic field of a turbulent lean cpremixed open flame is numerically investigated by a hybrid method solving the Navier-Stokes equations in a large-eddy simulation formulation and the acoustic perturbation equations. The interaction of acoustic modes of a burner plenum and the turbulent flame is analyzed with respect to the sound emission of the flame. It is investigated if a simplified computation
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Combustion instability modeling using multi-mode flame transfer functions and a nonlinear Euler solver Int. J. Spray Combust. Dyn. (IF 1.6) Pub Date : 2020-09-16 Gowtham Manikanta Reddy Tamanampudi, Swanand Sardeshmukh, William Anderson, Cheng Huang
Modern methods for predicting combustion dynamics in high-pressure combustors range from high-fidelity simulations of sub-scale model combustors, mostly for validation purposes or detailed investigations of physics, to linearized, acoustics-based analysis of full-scale practical combustors. Whereas the high-fidelity simulations presumably capture the detailed physics of mixing and heat addition, computational
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A review of phenomenological spray penetration modeling for diesel engines with advanced injection strategy Int. J. Spray Combust. Dyn. (IF 1.6) Pub Date : 2020-08-28 Long Liu, Yan Peng, Dai Liu, Changfu Han, Ningbo Zhao, Xiuzhen Ma
Driven by the increasingly remarkable problems of environmental pollution and energy crisis, the combustion optimization of diesel engine seems to be more urgent than ever, therefore, advanced injection strategies are gradually proposed and employed in modern diesel engines. Phenomenological model, which serves as an effective tool to conduct the parametric study on the spray penetration, needs to
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Effect of ambient pressure oscillation on the primary breakup of cylindrical liquid jet spray Int. J. Spray Combust. Dyn. (IF 1.6) Pub Date : 2020-07-22 Zhen Zhang, Dong-hyuk Shin
The present simulation study investigates the effects of ambient pressure oscillation on cylindrical liquid jet sprays, using the volume of fluid method. The research is motivated by combustion instability in combustion engines, where strong harmonic pressure oscillation can damage internal structures. Oscillating pressure modulates not only the fuel mass flow rate but also the ambient gas density
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Experimental study on flash-boiling spray structure of multi-hole gasoline direct injection injector in a constant volume chamber Int. J. Spray Combust. Dyn. (IF 1.6) Pub Date : 2020-07-10 Jian Wu, Jiakun Du, Hong Chen, Yuhuai Li, Wenfeng Zhan, Guangquan Wu, Lin Ye
The macroscopic and microscopic characteristics of flash-boiling spray were experimentally investigated with various optical measurement techniques. The effects of ambient pressure and fuel temperature on flash-boiling characteristics in multi-hole gasoline direct injection injector were analyzed. The analysis was focused on the spray structure and atomization droplet size distributions. In order to
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Analytical approximations for heat release rate laws in the time- and frequency-domains Int. J. Spray Combust. Dyn. (IF 1.6) Pub Date : 2020-07-05 Sreenath M Gopinathan, Alessandra Bigongiari, Maria Heckl
This paper focusses on the relationship between the heat release rate and the acoustic field, which is a crucial element in modelling thermoacoustic instabilities. The aim of the paper is twofold. The first aim is to develop a transformation tool, which makes it easy to switch between the time-domain representation (typically a heat release law involving time-lags) and the frequency-domain representation
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Injector-coupled transverse instabilities in a multi-element premixed combustor Int. J. Spray Combust. Dyn. (IF 1.6) Pub Date : 2020-06-25 John J Philo, Rohan M Gejji, Carson D Slabaugh
Combustion instabilities in a high-pressure, multi-element combustor are studied in order to understand the relationship between the chamber and injector dynamics. A linear array of seven injectors supplies premixed natural gas and air into a rectangular combustion chamber designed to promote high-frequency, transverse thermoacoustic instabilities. The effect of equivalence ratio on the combustion
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Detonation initiation by shock focusing at elevated pressure conditions in a pulse detonation combustor Int. J. Spray Combust. Dyn. (IF 1.6) Pub Date : 2020-06-22 Fabian E Habicht, Fatma C Yücel, Joshua AT Gray, Christian O Paschereit
This work contains experimental investigations on the correlation of the detonation initiation process via a shock-focusing device with various initial pressures and mass flow rates. A pulse detonation combustor is operated with stoichiometric hydrogen--air--oxygen mixtures in single cycle operation. A rotationally symmetric shock-focusing geometry evokes the onset of a detonation by the focusing of
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Study of plasma-assisted detonation initiation by quasi-direct current discharge Int. J. Spray Combust. Dyn. (IF 1.6) Pub Date : 2020-01-22 Siyin Zhou, Tianyi Shi, Wansheng Nie
Because a pulse detonation engine has the advantages of high thermal cycle efficiency, high thrust-to-weight ratio, low fuel consumption, and a simple structure, it is ideal for application to high-performance propulsion devices. The countries that lead the world in the aerospace field attach great importance to it and have made relatively large strides in theories, experiments, and simulations. However
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A review of pollutants emissions in various pressure gain combustors Int. J. Spray Combust. Dyn. (IF 1.6) Pub Date : 2019-08-30 Vijay Anand, Ephraim Gutmark
The primary pollutants from combustors are carbon monoxide (CO), carbon dioxide (CO2), NOx, and unburned hydrocarbons (UHC) among other particulate emissions. All of the above cause significant damages to the environment1 and/or the biological species residing in it.2–5 The combination of these pollutants cause a wide variety of issues in humans, mostly involving increased mortality, reduced capacity
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Excitation of the precessing vortex core by active flow control to suppress thermoacoustic instabilities in swirl flames Int. J. Spray Combust. Dyn. (IF 1.6) Pub Date : 2019-07-04 Finn Lückoff, Kilian Oberleithner
In modern gas turbine combustors, flame stabilization is typically achieved by an aerodynamic feature of swirling flows known as vortex breakdown. This phenomenon gives rise to an inner recirculation zone (IRZ) and corresponding inner and outer shear layers. Especially, the inner shear layer is prone to a global hydrodynamic instability known as the precessing vortex core (PVC).1 The PVC can be described
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Advances by the Marie Curie project TANGO in thermoacoustics Int. J. Spray Combust. Dyn. (IF 1.6) Pub Date : 2019-05-21 Maria Heckl
Thermoacoustic instabilities represent a serious problem for combustion-driven devices, such as gas turbine engines and domestic burners. These instabilities can cause intense pressure oscillations, which in turn causes excessive structural oscillations, fatigue and even catastrophic damage to combustor hardware. In recent years, the development of clean combustion systems with reduced pollution of
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Numerical simulation of gas–liquid flow behavior in the nozzle exit region of an effervescent atomizer Int. J. Spray Combust. Dyn. (IF 1.6) Pub Date : 2019-02-18 Chunhua Sun, Zhi Ning, Xinqi Qiao, Ming Lv, Juan Fu, Jin Zhao, Xintao Wang
Effervescent atomization is a two-phase liquid atomization technique developed in the late 1980s by Lefebvre et al.,1–3 and the promising technique for fields such as coating, fuel injection and combustion. This technique is differentiated from the premixing process of the two phases, and a variety of gas–liquid flow patterns are formed in the mixing chamber. This internal gas–liquid flow behavior
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Corrigendum Int. J. Spray Combust. Dyn. (IF 1.6) Pub Date : 2018-12-06
Aswathy Surendran, Maria A Heckl, Naseh Hosseini, Omke Jan Teerling (2018). Passive control of instabilities in combustion systems with heat exchanger. International Journal of Spray and Combustion Dynamics, first published online October 13, 2017. (Original DOI: https://doi.org/10.1177/1756827717731486)
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Analysis of the interaction of thermoacoustic modes with a Green’s function approach Int. J. Spray Combust. Dyn. (IF 1.6) Pub Date : 2018-12-06 Alessandra Bigongiari, Maria Heckl
Thermoacoustic instabilities are large-amplitude self-sustained oscillations of the acoustic field that are observed in various combustion systems.1,2 They arise as the result of thermoacoustic feedback, i.e. positive feedback between the heat source (typically a flame) and the acoustic field inside the combustor. What starts as a small perturbation in the acoustic field amplifies the rate of heat
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Advances by the Marie Curie project TANGO in thermoacoustics and aeroacoustics Int. J. Spray Combust. Dyn. (IF 1.6) Pub Date : 2018-12-06 Maria Heckl
This special issue features a selection of research papers produced by the project TANGO – an initial training network (ITN) with an international consortium of seven academic and five industrial partners. TANGO is the acronym for ‘Thermoacoustic and Aeroacoustic Nonlinearities in Green combustors with Orifice structures’. During the four years of its lifetime (2012–2016), a total of 15 young researchers
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Investigation of flame behavior and dynamics prior to lean blowout in a combustor with varying mixedness of reactants for the early detection of lean blowout Int. J. Spray Combust. Dyn. (IF 1.6) Pub Date : 2018-11-18 Somnath De, Arijit Bhattacharya, Sirshendu Mondal, Achintya Mukhopadhyay, Swarnendu Sen
A key challenge for the gas turbine combustors is to satisfy stringent emission standards while maintaining high efficiency towards the production of power or thrust. The pollutant formation, especially the NOx emission, can be reduced by using lean fuel–air mixture.1,2 However, in the lean regime of operation, the combustors are prone to a couple of major problems, namely, combustion instability and
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In situ identification strategy of thermoacoustic stability in annular combustors Int. J. Spray Combust. Dyn. (IF 1.6) Pub Date : 2018-09-11 Driek Rouwenhorst, Jakob Hermann, Wolfgang Polifke
In combustion systems with an annular combustion chamber, the low frequency azimuthal modes are a major concern regarding thermoacoustic stability. These modes, in which the flames of individual burners couple with acoustic waves traveling around the combustion chamber circumference, can reach such high amplitudes that a limited operability window must be accepted or structural damage might occur.