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Automating the generation of detailed kinetic models for halocarbon combustion with the Reaction Mechanism Generator Proc. Combust. Inst. (IF 3.4) Pub Date : 2023-04-03 David S. Farina, Sai Krishna Sirumalla, Richard H. West
Originally developed to predict the chemical kinetics of hydrocarbon combustion via automated generation of detailed reaction mechanisms, Reaction Mechanism Generator (RMG) contains extensive thermokinetic data for C,H,O chemisty, and has more recently been expanded to nitrogen and sulfur. In this work, we present the addition of halogen (fluorine, chlorine, and bromine) chemisty to RMG to enable automated
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Decarbonization of mobility, including transportation and renewable fuels Proc. Combust. Inst. (IF 3.4) Pub Date : 2023-03-11 Roger Cracknell, Steve Ciatti, Sergey Dorofeev, Ruud Eggels, Keith McManus, Koichi Nakata
An industrial panel session, focussed on ‘Decarbonization of Mobility’, was held at the 39th International Symposium of Combustion (ISOC) with representatives from GE, Rolls-Royce, Toyota, PACCAR, and FM Global – this paper is a summary of the discussion Hydrogen and fully electric aircraft are likely to be appropriate for some markets, with Sustainable Aviation Fuel (SAF) being required for many applications
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A machine learning framework to predict the aggregation of polycyclic aromatic compounds Proc. Combust. Inst. (IF 3.4) Pub Date : 2023-03-11 Jacob C. Saldinger, Paolo Elvati, Angela Violi
The physical aggregation of polycyclic aromatic compounds (PACs) is a key step in soot inception. In this work, we set out to elucidate which molecular properties of PACs influence the physical growth process and develop a machine learning framework to quantitatively relate these features to the propensity of PACs to physically dimerize. To this end, we identify a pool of compounds with a diverse range
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Syngas production from biogas in a polygeneration process: Simultaneous partial oxidation and dry reforming in a piston engine Proc. Combust. Inst. (IF 3.4) Pub Date : 2023-03-11 Kai Banke, Sebastian A. Kaiser
This work experimentally investigates the fuel-rich combustion of CH4/CO2/O2 mixtures in a piston engine. The focus of the experiments is to determine suitable operating parameters in terms of stable engine operation, syngas production, CO2 conversion, and avoiding soot emissions. In particular, the spark timing, CO2 intake mole fraction, equivalence ratio, and compression ratio were varied. Results
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A direct numerical simulation study on NO and N2O formation in turbulent premixed ammonia/hydrogen/nitrogen-air flames Proc. Combust. Inst. (IF 3.4) Pub Date : 2023-03-04 Martin Rieth, Andrea Gruber, Jacqueline H. Chen
The formation of nitric oxide (NO) and nitrous oxide (N2O) in turbulent NH3/H2/N2-air premixed flames is investigated utilizing three-dimensional Direct Numerical Simulation (DNS) with detailed chemical kinetics in order to gain insight on the role of equivalence ratio and pressure. To this end, results from five large-scale DNS in temporal jet and shear layer configurations with equivalence ratios
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Applying physics-informed enhanced super-resolution generative adversarial networks to turbulent premixed combustion and engine-like flame kernel direct numerical simulation data Proc. Combust. Inst. (IF 3.4) Pub Date : 2023-02-23 Mathis Bode, Michael Gauding, Dominik Goeb, Tobias Falkenstein, Heinz Pitsch
Models for finite-rate-chemistry in underresolved flows still pose one of the main challenges for predictive simulations of complex configurations. The problem gets even more challenging if turbulence is involved. This work advances the recently developed PIESRGAN modeling approach to turbulent premixed combustion. For that, the physical information processed by the network and considered in the loss
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Experimental and numerical investigation of ester droplet combustion: Application to butyl acetate Proc. Combust. Inst. (IF 3.4) Pub Date : 2023-02-18 Yujie Wang, Alberto Cuoci, Songtao Guo, Liang Ji, C. Thomas Avedisian, Kalyanasundaram Seshadri, Alessio Frassoldati
This paper presents an experimental and numerical study of the combustion of isolated n‑butyl acetate droplets in the standard atmosphere. Numerical simulations are reported using a model that incorporates unsteady gas and liquid transport, variable properties, and radiation. Three skeletal mechanisms of n‑butyl acetate, derived from a large detailed mechanism comprised of 819 species and 52,698 reactions
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The impact of N2 micro-jets on the V-to-M flame shape transition in a premixed swirl burner Proc. Combust. Inst. (IF 3.4) Pub Date : 2023-02-08 Donggang Cao, Inbar Greenberg, Nikhil Balasubramanian, Haim Elya Brod, Dan Michaels
Injection of N2 through micro-jets located on the dump plane of a lean premixed swirl stabilized combustor is investigated as a new method for mitigating combustion instabilities. This study focuses on the chemical and fluid dynamic processes by which the N2 micro-jets impact the flame dynamics. An experimental and numerical investigation is performed to characterize the combustion instability during
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Hydrodynamic effects of shock interactions on initial flame kernel development of close dual-point laser induced sparks Proc. Combust. Inst. (IF 3.4) Pub Date : 2023-02-08 Shinji Nakaya, Ren Eto, Takuto Yamaguchi, Takahiro Koseki, Mitsuhiro Tsue
Flame kernel formations of close dual-point laser induced sparks were investigated experimentally, focusing on the hydrodynamic effects induced by an interaction of shock waves produced by the laser induced sparks. Dual sparks were produced near the center of the combustion chamber by splitting of a ray emitted by a 532 nm Nd:YAG laser. Methane/air mixtures were ignited under a quiescent condition
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Species structures in preheated ammonia micro flames Proc. Combust. Inst. (IF 3.4) Pub Date : 2023-02-04 Yong Fan, Ziyue Wang, Yejun Wang, Minhyeok Lee, Waruna D. Kulatilaka, Yuji Suzuki
Species structure of ammonia (NH3) micro flames stabilized on a preheated 2-mm diameter tube is investigated using laser-induced fluorescence (LIF) measurements and numerical simulations with detailed reaction mechanisms. Nitric oxide (NO) and hydroxyl (OH) radicals are measured using single-photon absorption laser-induced fluorescence (LIF), while hydrogen atoms (H) are measured using two-photon absorption
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On the combined effects of compositional inhomogeneity and ammonia addition to turbulent flames of ethylene Proc. Combust. Inst. (IF 3.4) Pub Date : 2023-02-04 Wesley R. Boyette, Andrew R.W. Macfarlane, Scott A. Steinmetz, Matt J. Dunn, William L. Roberts, Assaad R. Masri
This paper is part of a broader program aimed at investigating the effects of co-firing clean fuels such as ammonia or hydrogen with hydrocarbons. The focus is on soot formation as well as flame stability in turbulent mixed-mode combustion, which is highly relevant in practical combustors. Ammonia substitution for nitrogen results in reduced flame stability, and this is correlated to differences in
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Redox kinetics of NiO/YSZ for chemical-looping combustion and the effect of support on reducibility Proc. Combust. Inst. (IF 3.4) Pub Date : 2023-01-30 Ahmed F. Ghoniem, Zhenlong Zhao, Mruthunjaya Uddi
This paper explores the reaction kinetics of NiO supported on YSZ (Yttria Stabilized Zirconia) as an oxygen carrier for chemical looping combustion. Nickel particles with size less than 1 μm mixed with YSZ nano-powders are used to prepare the solid mixture, with 45% mol of NiO. Redox reactivity and oxygen carrying capacity are measured in a laboratory scale fixed bed reactor in the temperature range
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Generalized description and extrapolation of extinction stretch rates from spherically expanding flames Proc. Combust. Inst. (IF 3.4) Pub Date : 2023-01-24 Wenkai Liang, Chung K. Law
The extinction stretch/strain rate is an important global parameter for validating kinetics and modeling laminar and turbulent flame extinctions. Here, we propose a generalized approach to extrapolate the extinction stretch rate from spherically expanding flames, based on the nonlinear relation between the flame speed and the stretch rate applicable to general Lewis numbers (Le’s). Results show that
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Polycyclic aromatic hydrocarbons production from the supercritical pyrolysis of n-decane, ethylcyclohexane, and n-decane/ethylcyclohexane blends Proc. Combust. Inst. (IF 3.4) Pub Date : 2023-01-21 Avinash R. Mali, Karthik Vutukuru, Mary J. Wornat
To investigate the effects of fuel composition on the production and growth of polycyclic aromatic hydrocarbons (PAH) at conditions relevant to the pre-combustion environment of fuels in future high-speed aircraft, we have conducted supercritical pyrolysis experiments in an isothermal, silica-lined stainless-steel flow reactor at 568 °C, 94.6 atm, and 133 s, with the model fuels n-decane and ethylcyclohexane—as
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Enhancing ammonia combustion using reactivity stratification with hydrogen addition Proc. Combust. Inst. (IF 3.4) Pub Date : 2023-01-23 Wenkai Liang, Chung K. Law
In this paper, we propose a new method to enhance the burning rate of ammonia through reactivity stratification by using the binary fuel of ammonia and hydrogen. It is found that stratification from the high-reactivity fuel, hydrogen, to the low-reactivity fuel, ammonia, can substantially increase the flame speed of the low-reactivity, ammonia/air mixture. Moreover, the enhancement can sustain for
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On the role of HNNO in NOx formation Proc. Combust. Inst. (IF 3.4) Pub Date : 2023-01-19 Qinghui Meng, Lei Lei, Joe Lee, Michael P. Burke
The formation of nitrogen oxides (NOx) during combustion is a topic of substantial fundamental and practical interest, given the complex nature of its formation kinetics and the fact that, as a highly regulated pollutant emission, it is a major constraint in engineering design. To date, there are four known mechanisms by which the strong N–N bond can be broken to facilitate NOx formation from N2 present
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Incorporation of film theory in single droplet combustion model for prediction of precursor release in flame spray pyrolysis Proc. Combust. Inst. (IF 3.4) Pub Date : 2023-01-16 Musa Najimu, Vicki Baghdassarian, Scott Leask, Vincent McDonell, Bihter Padak, Erdem Sasmaz
The precursor release rate during flame synthesis has been shown to influence the uniformity of synthesized particles. However, its quantification through single droplet combustion modeling was based on its immediate release from the droplet without considering the effect of the mass boundary layer surrounding the droplet. Here, the film theory is applied with the single droplet combustion model to
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Plasma-assisted deflagration to detonation transition in a microchannel with fast-frame imaging and hybrid fs/ps coherent anti-Stokes Raman scattering measurements Proc. Combust. Inst. (IF 3.4) Pub Date : 2023-01-19 Madeline Vorenkamp, Scott A. Steinmetz, Timothy Y. Chen, Xingqian Mao, Andrey Starikovskiy, Christopher Kliewer, Yiguang Ju
This study examines kinetic enhancement by nanosecond dielectric barrier discharge (ns-DBD) plasma on fuel-lean, Φ = 0.7, dimethyl ether (DME), oxygen (O2), and argon (Ar) premixture during deflagration to detonation transition (DDT) experiments in a microchannel. Nonequilibrium plasma produces active species and radicals as well as fast and slow heating of a mixture to promote ignition due to energetic
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A flame technique to isolate the detonation/product interface relevant to rotating detonation engines Proc. Combust. Inst. (IF 3.4) Pub Date : 2023-01-09 Kevin Cheevers, Hongxia Yang, Mihir Raut, Zekai Hong, Matei Radulescu
A novel experimental technique is proposed to study the detonation propagation in a layer of non-reacted gas weakly confined by combustion products. This problem is relevant to rotating detonation engines, where transverse detonations are confined by products of a previous rotation cycle, and other applications such as industrial safety. The experimental technique utilizes a flame ignited along the
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Lightning-induced smoldering ignition of peat: Simulation experiments by an electric arc with long continuing current Proc. Combust. Inst. (IF 3.4) Pub Date : 2023-01-03 Hongmin Zhang, Pengcheng Guo, Haixiang Chen, Naian Liu, Yiqian Qiao, Mingrui Xu, Linhe Zhang
Lightning is one of the essential causes of wildfires. However, the ignition criteria for lightning-caused wildfires have significant limitations due to a lack of understanding of the ignition mechanism. This work aims to reveal the mechanism of lightning-induced smoldering ignition of wildland fuels and explore a more reasonable ignition criterion by experimental means. The solidified peat cake samples
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Sooting tendencies of ethylene diffusion flame doped by C3-C5 alcohols Proc. Combust. Inst. (IF 3.4) Pub Date : 2022-12-22 R. Jalain, J. Bonnety, G. Legros, A. Matynia
The sooting propensity of steady laminar coflow ethylene/air flames is modified doping the fuel stream with vapors of alcohol and evaluated as a function of both the position of the alcohol function and the ramification level (linear/branched) of the molecule. To identify general trends, a range of 3 alcohol sizes (C3, C4, and C5) are compared: the 2 propanol isomers (primary and secondary), the 4
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Nonlinear dynamics of attenuation behavior in combustion oscillations in a swirl-stabilized combustor Proc. Combust. Inst. (IF 3.4) Pub Date : 2022-12-22 Yosuke Mori, Takeshi Kawada, Shingo Fukuda, Hiroshi Gotoda
We experimentally examine the attenuation behavior in combustion oscillations from the perspective of symbolic dynamics, dynamical systems theory, complex networks, and machine learning. The periodicity of combustion oscillations gradually decreases with increasing amount of air steadily injected into flame base, maintaining a nearly in-phase synchronized state between pressure and OH* chemiluminescence
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Opposed-flow flame spread over carbon fiber reinforced plastic with different carbon fiber orientations Proc. Combust. Inst. (IF 3.4) Pub Date : 2022-12-21 Yoshinari Kobayashi, Keisuke Matsumoto, Naoki Matsukawa, Shuhei Takahashi
Herein, carbon fiber reinforced plastic (CFRP) sheets with different carbon fiber (CF) orientations were combusted in an environment of variable opposed-flow velocity (Vg) and oxygen concentration, and the effects of the CF orientation angle (θ) on the flame spread characteristics were studied. The limiting oxygen concentration increased with θ and linearly decreased with increasing Vg. The flame spread
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Blowout limits of inclined nonpremixed turbulent jet flames Proc. Combust. Inst. (IF 3.4) Pub Date : 2022-12-14 Qiang Wang, Xuan Liang, Aquan Lu, Ben Wang, Osamu Fujita, Suk Ho Chung, Longhua Hu
The blowout behavior of inclined nonpremixed turbulent jet flames is investigated by varying the jet inclined angle in the range of -90° to 90° The critical jet velocity at blow-out limit is quantified experimentally for various nozzle diameters, different fuels and inclined angles. Numerical simulations are performed to emphasize the flow field difference for the positive and negative inclined angles
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Dynamics of Chapman-Jouguet pulsating detonations with Chain-Branching kinetics: Fickett’s analogue and Euler equations Proc. Combust. Inst. (IF 3.4) Pub Date : 2022-12-15 Aliou Sow, S.-M. Lau-Chapdelaine, Matei I. Radulescu
The present study examines the spatiotemporal nonlinear dynamics of detonations over a wide range of reaction time scales away from the neutral stability region. This is addressed by one-dimensional numerical simulations with chain-branching kinetics. Fickett’s detonation analogue and Euler’s equations were used as evolution equations. A shock-fitting solver is used to reduce CPU time. Up to four thousand
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A dynamical system approach for solving the steady structure of high speed deflagrations Proc. Combust. Inst. (IF 3.4) Pub Date : 2022-12-15 Willstrong Rakotoarison, Matei I. Radulescu
High-speed deflagrations have burning velocities much higher than laminar ones, and compressible effects become important. In the present paper, we study the structure of such high speed deflagrations in the thickened flame limit for a one-step Arrhenius rate law, whereby the transport coefficients are increased to give rise to buring velocities of finite Mach number. We study their steady structure
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Lattice Boltzmann method with nonreflective boundary conditions for low Mach number combustion Proc. Combust. Inst. (IF 3.4) Pub Date : 2022-12-14 Zhen Wang, Timan Lei, Kai Hong Luo
The paper presents a lattice Boltzmann (LB) method for premixed and nonpremixed combustion simulations with nonreflective boundary conditions, in contrast to Navier–Stokes solvers or hybrid schemes. The current approach employs different sets of distribution functions for flow, temperature and species fields, which are fully coupled. The discrete equilibrium density distributions are obtained from
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Understanding the low-temperature chemistry of 1,2,4-trimethylbenzene Proc. Combust. Inst. (IF 3.4) Pub Date : 2022-12-09 Shijun Dong, Goutham Kukkadapu, Jinhu Liang, Xiaobei Cheng, Scott W. Wagnon, William J. Pitz, Henry J. Curran
1,2,4-trimethylbenzene is an important representative aromatic component of gasoline/diesel/jet fuels and thus it is necessary to understand its low-temperature chemistry. In this paper, ignition delay times (IDTs) of both 1,2,4-trimethylbenzene (124TMB) and its blends with n-heptane were measured at engine-like conditions using both a high-pressure shock tube and a rapid compression machine for fuel
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Temperature evolution, flame behavior and extinction inside compartment with a ceiling vent under the ambient wind Proc. Combust. Inst. (IF 3.4) Pub Date : 2022-12-10 Xiang Fang, Xiepeng Sun, Xiaolei Zhang, Fei Ren, Yong Yang, Longhua Hu
This article presents an experimental and CFD simulation investigation and analysis on temperature evolution and flame behavior inside compartment with a ceiling vent under ambient wind. Experiments were conducted employing a reduced-scale model containing a cubic fire compartment with a ceiling vent under the external wind generated by a wind tunnel. The temperature of windward and leeward inside
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Critical diffraction of irregular structure detonations and their predictability from experimentally obtained D−κ data Proc. Combust. Inst. (IF 3.4) Pub Date : 2022-12-10 Farzane Zangene, Qiang Xiao, Matei Radulescu
The present work reports new experiments of detonation diffraction in a 2D channel configuration in stoichiometric mixtures of ethylene, ethane, and methane with oxygen as oxidizer. The flow field details are obtained using high-speed schlieren near the critical conditions of diffraction. The critical initial pressure for successful diffraction is reported for the ethylene, ethane and methane mixtures
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Modeling soot formation in flames and reactors: Recent progress and current challenges Proc. Combust. Inst. (IF 3.4) Pub Date : 2022-12-08 Murray J. Thomson
The study of soot has long been motivated by its adverse impacts on health and the environment. However, this combustion knowledge is also relevant to the production of carbon black and hydrogen via methane pyrolysis which are important commodities. Over the last decade, steady progress has been made in the development of detailed continuum models of soot formation in flames and reactors. Developing
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An experimental and modeling study on autoignition of 2-phenylethanol and its blends with n-heptane Proc. Combust. Inst. (IF 3.4) Pub Date : 2022-12-08 Ruozhou Fang, Goutham Kukkadapu, Scott W. Wagnon, William J. Pitz, Chih-Jen Sung
2-Phenylethanol (2-PE) is an aromatic alcohol with high research octane number, high octane sensitivity, and a potential to be produced using biomass. Considering that 2-PE can be used as a fuel additive for boosting the anti-knocking quality of gasoline in spark-ignition engines and as the low reactivity fuel or fuel component in dual-fuel reactivity controlled compression ignition (RCCI) engines
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Role of CH2O moiety on laminar burning velocities of oxymethylene ethers (OMEn): A case study of dimethyl ether, OME1 and OME2 Proc. Combust. Inst. (IF 3.4) Pub Date : 2022-12-08 Wei Li, Qilong Fang, Jianguo Zhang, Yanpak Chow, Lili Ye, Yuyang Li
Oxymethylene ethers (OMEn) are an important family of e-fuels that can be produced sustainably from carbon dioxide and hydrogen via renewable electricity. In this work, laminar flame propagation of dimethyl ether (DME, which can be deemed as OME0), dimethoxymethane (OME1) and methoxy(methoxymethoxy)methane (OME2) was investigated in a constant-volume cylindrical combustion vessel. Laminar burning velocities
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Experimental and numerical study of product gas and N2O emission characteristics of ammonia/hydrogen/air premixed laminar flames stabilized in a stagnation flow Proc. Combust. Inst. (IF 3.4) Pub Date : 2022-12-07 Akihiro Hayakawa, Masao Hayashi, Marina Kovaleva, Gabriel J. Gotama, Ekenechukwu C. Okafor, Sophie Colson, Syed Mashruk, Agustin Valera-Medina, Taku Kudo, Hideaki Kobayashi
In order to achieve carbon neutrality, the use of ammonia as a fuel for power generation is highly anticipated. The utilization of a binary fuel consisting of ammonia and hydrogen can address the weak flame characteristics of ammonia. In this study, the product gas characteristics of ammonia/hydrogen/air premixed laminar flames stabilized in a stagnation flow were experimentally and numerically investigated
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Influence of low-temperature chemistry on steady detonations with curvature losses Proc. Combust. Inst. (IF 3.4) Pub Date : 2022-12-08 F. Veiga-López, Z.F. Weng, R. Mével, J. Melguizo-Gavilanes
The influence of low temperature chemistry (LTC) on the locus of steady solutions predicted by a ZND model with curvature losses and detailed kinetics was assessed using undiluted / CO2-diluted stoichiometric DME-O2 mixtures. Results show (i) the existence of an additional critical point at large velocity deficits when the LTC submechanism is included in the reaction model, and (ii) a shift in the
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A numerical study on the influence of increased instability of quasi-detonation on the critical tube diameter phenomenon Proc. Combust. Inst. (IF 3.4) Pub Date : 2022-12-08 Chian Yan, Hoi Dick Ng, Xiaocheng Mi
At critical conditions, the effect of instability plays a prominent role in the gaseous detonation transmission from a tube into an unconfined space. This study aims to clarify such an effect by investigating the critical tube diameter of quasi-detonations, i.e., detonations under the influence of minor perturbations along the tube walls. The strategy is to conduct two-dimensional numerical simulations
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Intrinsic kinetics mechanisms for the catalytic reduction of NO by Na-loaded char Proc. Combust. Inst. (IF 3.4) Pub Date : 2022-12-08 Shuang Yue, Chunbo Wang, Edward J. Anthony
An insight into the interaction between NO and Na-loaded char is essential to improve the catalytic ability of Na to NO reduction, which will be useful to lower NO emissions during thermal utilization of sodium-containing fuels. Here, the intrinsic kinetics mechanisms for the catalytic reduction of NO by Na-loaded char were discussed in details. Using density functional theory (DFT) calculations, possible
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Exploring the chemistry behind low temperature auto-ignition of isopropyl nitrate in an RCM: An experimental and kinetic modeling study Proc. Combust. Inst. (IF 3.4) Pub Date : 2022-12-05 Qifeng Hou, Weitao Liu, Zhaohan Chu, Xiaoqing Wu, Mengqi Wu, Zhongkai Liu, Shiyao Niu, Feng Zhang
The low-temperature auto-ignition chemistry of isopropyl nitrate (iPN) was experimentally and numerically investigated in the present study. The ignition delay times (IDTs) of iPN were measured stoichiometrically over a temperature range of 560–600 K at effective pressures of 5 and 10 bar in a rapid compression machine. A two-stage ignition phenomenon of iPN was observed. Both the first-stage IDTs
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Pressure gradient tailoring effects on vorticity dynamics in the near-wake of bluff-body premixed flames Proc. Combust. Inst. (IF 3.4) Pub Date : 2022-12-05 Samuel H.R. Whitman, Tyler J. Souders, Michael A. Meehan, James G. Brasseur, Peter E. Hamlington
We investigate the role of mean streamwise pressure gradients in the development of a bluff-body-stabilized premixed flame in the near-wake of the bluff body. To this end, a triangular prism flame holder is situated in three different channel geometries: a nominal case with straight walls, a nozzle with a stronger mean pressure gradient, and a diffuser with a comparatively weaker mean pressure gradient
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Experimental study of forced synchronization and cross-coupling in a liquid-fuelled gas turbine combustor at elevated pressure Proc. Combust. Inst. (IF 3.4) Pub Date : 2022-12-07 Mitchell L. Passarelli, Askar Kazbekov, Victor Salazar, Krishna Venkatesan, Adam M. Steinberg
The effects of external forcing on a turbulent, liquid-fuelled, swirl-stabilized gas turbine combustor operating at a pressure of approximately 1 MPa are explored experimentally. In particular, the dynamics and coupling between the hydrodynamics, flame dynamics and acoustics are compared for various forcing amplitudes at a fixed forcing frequency ff. The hydrodynamics were characterized via laser Mie
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Ignition behaviors of primary reference fuels in a rapid compression machine under vortex-existing/minimized conditions Proc. Combust. Inst. (IF 3.4) Pub Date : 2022-12-05 Wei Liu, Yunliang Qi, Ridong Zhang, Qihang Zhang, Zhi Wang
Knock is one of the main obstacles to improving the thermal efficiency of spark-ignition internal combustion engines. Although knock has been widely studied and accepted as a result of end-gas auto-ignition, the fundamentals regarding auto-ignition behaviors are still not fully revealed. In this study, the ignition behaviors of primary reference fuels were investigated in an optical rapid compression
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On explosion limits of NCA battery vent gas Proc. Combust. Inst. (IF 3.4) Pub Date : 2022-12-05 Ruiguang Yu, Jie Liu, Wenkai Liang, Chung K. Law, Hewu Wang, Minggao Ouyang
Using Lix (Ni0.80Co0.15Al0.05)O2 (NCA) battery vent gas (BVG) as an archetypical multi-component mixture, a comprehensive computational investigation with detailed chemical kinetics is conducted on its pressure-temperature explosion limits response characteristics under different states of charge (SOC) and equivalence ratios conditions. The results show that the BVG explosion limits exhibit the characteristics
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Experimental and modeling study on the ignition delay times of ammonia/methane mixtures at high dilution and high temperatures Proc. Combust. Inst. (IF 3.4) Pub Date : 2022-12-05 Jiacheng Liu, Chun Zou, Jianghui Luo
Ammonia is a promising alternative clean fuel due to its carbon-free character and high hydrogen density. However, the low reactivity of ammonia and the potential high NOx emissions hinder its applications. Blending methane into ammonia can effectively improve the reactivity of pure NH3. In addition, lean combustion, as a high-efficiency and low-pollution combustion technology, is an effective measure
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Effects of low-temperature chemistry on direct detonation initiation by a hot spot under engine conditions Proc. Combust. Inst. (IF 3.4) Pub Date : 2022-12-05 Minh Bau Luong, Hong G. Im
This study investigates the effect of low-temperature chemistry (LTC) on the minimum runup distance, lm, of direct detonation initiation by an autoignitive hot spot under engine conditions. A newly predictive model is proposed to determine an a priori lm. The temperature and pressure increase and the radical build-up prior to the main ignition resulting from LTC are incorporated in the model that allows
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Numerical simulation of laminar premixed hydrogen-air flame/shock interaction in semi-closed channel Proc. Combust. Inst. (IF 3.4) Pub Date : 2022-12-05 Emilie Yhuel, Guillaume Ribert, Pascale Domingo
Highly refined simulations of flame/shock interactions (FSI) are performed and analyzed in the context of hydrogen/air combustion in a two-dimensional shock-tube configuration (height 7 cm). The chemical mechanism used for the hydrogen oxidation contains 9 reactive species, without nitrogen oxides, and 23 kinetic reactions. An initially planar laminar premixed flame (ϕ = 0.8, P=20 kPa) is left to evolve
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Studies on the valveless scheme to produce high-frequency detonations with different purge methods Proc. Combust. Inst. (IF 3.4) Pub Date : 2022-12-02 Ke Wang, Xiaodong Yu, Yukun Zhang, Yonghui Zhang, Xinyu Huang, Wei Fan
Producing high-frequency detonations is an important topic for pulse detonations which has received considerable attentions. The valveless scheme has been verified to be able to obtain high-frequency detonations more than 100 Hz. This work has been conducted to investigate the possibility to achieve a higher detonation frequency and clarify the limits of stable operations preliminarily for the valveless
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Liquid fuel refill dynamics in a rotating detonation combustor using megahertz planar laser-induced fluorescence Proc. Combust. Inst. (IF 3.4) Pub Date : 2022-12-01 Matthew W. Hoeper, Austin M. Webb, Venkat Athmanathan, Robert B. Wang, H. Douglas Perkins, Sukesh Roy, Terrence R. Meyer, Christopher A. Fugger
The highly dynamic response of a continuously injected liquid fuel jet to rotating detonation waves is a critical parameter in the design, performance optimization, and modeling of a rotating detonation engine (RDE). In this work, this response is spatio-temporally resolved from the fuel injection point to the detonation channel using planar laser-induced fluorescence (PLIF) at imaging rates up to
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Investigation of soot sensitivity to strain rate in ethylene counterflow soot formation oxidation flames Proc. Combust. Inst. (IF 3.4) Pub Date : 2022-11-29 Erica Quadarella, Zepeng Li, Junjun Guo, William L. Roberts, Hong G. Im
Soot sensitivity to strain rate is mainly responsible for soot formation intermittence in practical combustion devices. This work provides a fundamental study on soot formation in Soot Formation Oxidation (SFO) counterflow flames at varying strain rates. While the problem has been extensively studied in Soot Formation (SF) configurations, where the dominant process is nucleation, investigations remain
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Understanding the role of fire retardants on the discontinuous ignition of wildland fuels Proc. Combust. Inst. (IF 3.4) Pub Date : 2022-11-30 José Ignacio Rivera, Fernando Ebensperger, Francisco Valenzuela, Leonardo Escandar, Pedro Reszka, Andrés Fuentes
This work reports on a theoretical and experimental study on the role of fire retardant treatments on the discontinuous ignition of wildland fuels. The effect of the concentration of fire retardant in the solution applied to the vegetation is as expected to increase the ignition delay time. We found that the fire retardant modifies the fuel bed effective thermophysical properties, delaying the thermal
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Effects of mechanically-induced oscillations on soot formation and flame temperature in laminar diffusion flames of ethylene Proc. Combust. Inst. (IF 3.4) Pub Date : 2022-11-28 Marek Serwin, Ahmet E. Karataş
An experimental study was performed to measure the effects of flame oscillations on soot concentration and flame temperature in co-flow laminar diffusion flames of ethylene. One novel aspect of this study is that flame oscillations were mechanically induced by moving the burner assembly in a reciprocating motion with an industrial computer-controlled linear stage. Motor speed was used to control the
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Effects of body force on the statistical behaviour and modelling of scalar variance in turbulent premixed flames Proc. Combust. Inst. (IF 3.4) Pub Date : 2022-11-23 Arun Ravi Varma, Umair Ahmed, Nilanjan Chakraborty
The effects of body force/external pressure gradient on the statistical behaviours of the reaction progress variable variance and the terms of its transport equation have been investigated for different turbulence intensities using DNS data of statistically planar flames. Since the extent of flame wrinkling increases with the strengthening of body force promoting unstable stratification, the scalar
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Experimental analysis and theoretical lift-off criterion for H2/air flames stabilized on a dual swirl injector Proc. Combust. Inst. (IF 3.4) Pub Date : 2022-11-25 Sylvain Marragou, Hervé Magnes, Andrea Aniello, Laurent Selle, Thierry Poinsot, Thierry Schuller
Stabilization mechanisms of partially premixed H2/air flames on a coaxial dual swirl injector are investigated at atmospheric conditions. Hydrogen is injected through a central duct, and the air by the outer annular channel. Both channels are swirled and two stabilization modes are observed depending on the geometrical configuration of the injector and on the operating conditions. In certain regimes
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Detailed unsteady dynamics of flame-flow interactions during combustion instability and its transition scenario for lean-premixed low-swirl hydrogen turbulent flames Proc. Combust. Inst. (IF 3.4) Pub Date : 2022-11-25 Takeshi Shoji, Shigeru Tachibana, Yoshihiro Nakazumi, Ryota Fujii, Judai Masugi, Takeshi Yokomori
This experimental study elucidates the unsteady dynamics of flame-flow interactions during unique thermoacoustic instability (TI) and the transition mechanism from stable combustion to TI for lean-premixed hydrogen turbulent jet flames in a low-swirl combustor (LSC), where a swirler assembly consists of an unswirled central region (CR) and an annular swirler region (SR). Simultaneous 200-kHz pressure
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Simultaneous catalytic ozonation of NO and dichloromethane on Mn/H-ZSM-5 catalysts: Interaction effect and mechanism Proc. Combust. Inst. (IF 3.4) Pub Date : 2022-11-24 Hairong Tang, Yong He, Fawei Lin, Yanqun Zhu, Yaxin Duan, Zhihua Wang
Catalytic ozonation is a promising method for simultaneous removal of NOx and Cl-VOCs, but needs to clarify their interaction mechanism and the influence of catalyst acidity. In this paper, the simultaneous catalytic ozonation of NO and dichloromethane (DCM) on Mn/H-ZSM-5 molecular sieve catalysts were investigated experimentally. Results show that the overall acidity, acid sites type and intensity
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Large eddy simulation of multi-regime combustion with a two-progress variable approach for carbon monoxide Proc. Combust. Inst. (IF 3.4) Pub Date : 2022-11-22 James C. Massey, Zhiyi Li, Zhi X. Chen, Yusuke Tanaka, Nedunchezhian Swaminathan
Simulations of two cases in a novel multi-regime burner configuration are undertaken using a presumed joint probability density function (PDF) approach with tabulated chemistry. The flame conditions are varied by changing the central jet equivalence ratio, which produces different multi-regime combustion modes in the non-premixed inner flame. An outer premixed flame and recirculation zone behind a
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Lift-off region temperature field and planar flow field of a twin-nozzle reacting jet in hot crossflow Proc. Combust. Inst. (IF 3.4) Pub Date : 2022-11-22 Zhen Wang, Yayao Wang, Xunchen Liu
Secondary fuel injection affects the combustion organization and flame dynamic in axial fuel staging gas turbines. Here, we experimentally investigate a front-fuel rear-air twin-nozzle configuration in which the fuel and air can be independently injected to stabilize a lifted flame front, control the jet trajectory and tune the combustion mode in a very flexible way. A high repetition two-line formaldehyde
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On the low-temperature chemistry of 1,3-butadiene Proc. Combust. Inst. (IF 3.4) Pub Date : 2022-11-21 Shijun Dong, Bowen Wang, Zuozhou Jiang, Xiaobei Cheng, Bingzhi Liu, Hong Wang, Zhandong Wang, Chong-Wen Zhou, Henry Curran
In this paper, species versus temperature profiles were measured during the oxidation of 1,3-butadiene in a jet-stirred reactor (JSR) at 1 atm, at different equivalence ratios (φ = 0.5, 1.0 and 2.0), in the temperature range 600 – 1020 K. Both synchrotron vacuum ultraviolet photoionization mass spectrometry (SVUV-PIMS) and gas chromatography (GC) methods were used to analyze the species. The experimental
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Formation and flame characteristics of the blue whirl Proc. Combust. Inst. (IF 3.4) Pub Date : 2022-11-21 Zixian Chen, Zhiyang Liu, Lei Liu, Huahua Xiao
The blue whirl is a newly-discovered fire phenomenon that has attracted widespread attention because of its unique flame structure and potential advantages in fuel-spill cleanup. This paper presents an experimental and theoretical study of blue whirl generated from a traditional fire whirl over a water surface in an apparatus consisting of two offset, quartz half-cylinders. The added ventilation overhead
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Vortex dynamics in different combustion regions of a cavity-based scramjet Proc. Combust. Inst. (IF 3.4) Pub Date : 2022-11-21 Donggang Cao, Haim Elya Brod, Neta Yokev, Dan Michaels
A hybrid RANS/LES study of a cavity-based scramjet was performed and reasonable agreements were found between simulation results and experimental measurements. In the current case, the flame was stabilized by the subsonic cavity shear layer and propagated downstream into the supersonic flow. The vortex dynamic in the flow, mixing, and combustion regions was comparatively investigated. The averaged
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Analysis of spatial-temporal dynamics of cool flame oscillation phenomenon occurred around a fuel droplet array by using variational auto-encoder Proc. Combust. Inst. (IF 3.4) Pub Date : 2022-11-19 Kazuki Iemura, Masanori Saito, Yusuke Suganuma, Masao Kikuchi, Yuko Inatomi, Hiroshi Nomura, Mitsuaki Tanabe
Cool flame oscillation of a fuel droplet array in high-temperature air was numerically simulated by using a droplet vaporization/spontaneous ignition numerical model. The time series data of temperature and chemical species spatial distributions were obtained. The data were used to train a Variational Auto-Encoder (VAE) that reduces the dimension of the data. The cool flame oscillation phenomenon was