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Combustion and plume-plasma characteristics of cesium-based solid propellant Combust. Flame (IF 4.4) Pub Date : 2024-03-16 Zhiwen Wang, Hui Wang, Lian Li, Qianyi Zhang, Feng Li, Ruiqi Shen, Yinghua Ye, Wei Zhang
The high-temperature plume of solid propellant has spawned considerable amount of highly ionized plasma, which can be used to increase the specific impulse of propellant with the external physical field, as well as serve as the charged particles for the (MHD) generator on the thruster. Unfortunately, the deficiency of workable deal to promote the electrical performance of the plume hinders the development
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Influence of slit asymmetry on blow-off and flashback in methane/hydrogen laminar premixed burners Combust. Flame (IF 4.4) Pub Date : 2024-03-16 H. Pers, P.A. Masset, E. Flores-Montoya, L. Selle, T. Schuller
One way to decarbonize the heat production sector is to gradually replace natural gas with hydrogen. The design of laminar premixed burners capable of operating with both methane and hydrogen is however challenging as these fuels have drastically different burning properties, which narrows the operating range. While methane flames face limitations in stabilization due to blow-off at high power, hydrogen
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A detailed kinetic submechanism for OH[formula omitted] chemiluminescence in hydrogen combustion revisited. Part 2 Combust. Flame (IF 4.4) Pub Date : 2024-03-15 Alexander S. Sharipov, Boris I. Loukhovitski, Alexey V. Pelevkin, Mayya R. Korshunova
In this series of two papers, we present a novel physically sound kinetic submechanism aimed at modeling the formation and decay of chemiluminescent (electronically excited) OH molecules in the ignition and combustion of hydrogen and hydrogen-based mixtures over a wide range of temperatures and pressures. The present Part describes the construction of this detailed reaction submechanism based on the
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Near-limit detonation in long spiral tube: An improved experimental methodology and frequency analysis Combust. Flame (IF 4.4) Pub Date : 2024-03-15 Zhaoyuan Huang, Zihang Ni, Zongtai Li, Zifeng Weng, Damir Valiev, Rémy Mével
In the present work, near-limit detonations in near stoichiometric propane-oxygen mixtures were investigated using a long spiral tube facility. Compared to previous studies, our improvements in the tube length, framing rate and resolution, image processing methods for distortion correction and detonation front detection, allow for a significant increase of the amount and quality of data obtained. As
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Impact of multi-component description of hydrophilic fuel droplets in propagating spray flames Combust. Flame (IF 4.4) Pub Date : 2024-03-15 Fernando Luiz Sacomano Filho, Luís Eduardo de Albuquerque Paixão e Freire de Carvalho, Artur Carvalho Santos, Aymeric Vié, Jeroen Adrianus van Oijen
The need for an accurate description of the fuel composition is emerging in recently published studies on the interaction of droplets and flames. In this context, hydrophilic fuels are of particular importance, since they are expected to interact with the water formed during combustion reactions. The impact of such interactions onto the reaction process is still not explored enough. This work aims
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Combustion enhancement of boron-containing fuel-rich mixture by steam reforming in a supersonic flow Combust. Flame (IF 4.4) Pub Date : 2024-03-14 Chaolong Li, Weiguang Cai, Zhixun Xia, Likun Ma, Shu Zheng, Binbin Chen, Yunchao Feng, Jiarui Zhang
In this paper, a novel experimental investigation was conducted to enhance the combustion of boron-containing fuel-rich mixture by steam reforming in a supersonic flow. The ground direct-connected experiments were designed to simulate a flight condition at Mach number 5.9 and an altitude of 25 km. The operating characteristics and performance evaluation of the scramjet combustor were analyzed and discussed
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On the structure and dynamics of strong and weak eigenvalue detonation in condensed explosives Combust. Flame (IF 4.4) Pub Date : 2024-03-14 Vincent R. Schuetz, D. Scott Stewart
An eigenvalue detonation, also known as a pathological detonation, is a detonation with incomplete reaction at a point in the detonation reaction zone, that is sonic relative to the leading shock. Aluminized explosives are made by combining a molecular explosive with aluminum and other additives. During detonation, the molecular explosive’s first exothermic decomposition generates products that react
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Experimental study of ignition and combustion characteristics assisted by laser-induced plasma during oxy-coal atmosphere by optical emission spectroscopy Combust. Flame (IF 4.4) Pub Date : 2024-03-14 Wenkun Zhu, Mengfan Yuan, Xiaohui Li, Long Gao, Yonghong Yan, Jiangbo Peng, Zhuozhi Wang, Wenbei Liu, Rui Sun
This investigation aims to understand the enhancement characteristics of plasma-assisted combustion in oxy-coal combustion. A 1064 nm Nd:YAG laser was added into a laminar flow reactor to produce laser-induced plasmas (LIPs). The high-speed visualization of the coal flame was used to reveal combustion's progress and evolution following laser-induced breakdown. To the best of our knowledge, this is
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Phenomenological regression rate model in axial injection end-burning hybrid rocket motor using different oxidizers Combust. Flame (IF 4.4) Pub Date : 2024-03-14 Giuseppe Gallo, Mai Fukada, Sho Suzuki, Harunori Nagata
Compared with conventional configurations, axial-injection end-burning hybrid rocket motors work with multiport fuel grains, which mainly burn in the axial direction. The consumption rate is controlled by the several flames developed at the end of each port. Although many studies of performance and flame stability have been carried out in the past, a phenomenological model of the axial regression rate
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Super adiabatic combustion of H2/Air and H2/N2O mixtures Combust. Flame (IF 4.4) Pub Date : 2024-03-14 Jennifer L. Schurr, Atmadeep Bhattacharya, Alexander A. Konnov, Ossi Kaario
While the impact of H chemistry on super adiabatic flame temperature (SAFT) for hydrocarbons is well understood, super adiabaticity for premixed H combustion has not been previously reported. In the present work, for the first time, premixed H/air and H/NO combustion in 0D and 1D context have been analysed to show that the instantaneous (0D) or local (1D) temperature exceeds the equilibrium temperature
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A detailed kinetic submechanism for OH[formula omitted] chemiluminescence in hydrogen combustion revisited. Part 1 Combust. Flame (IF 4.4) Pub Date : 2024-03-13 Alexander S. Sharipov, Boris I. Loukhovitski, Alexey V. Pelevkin, Mayya R. Korshunova
In this series of two papers, we present a novel physically sound kinetic submechanism aimed at modeling the formation and decay of chemiluminescent (electronically excited) OH molecules in the ignition and combustion of hydrogen and hydrogen-based mixtures over a wide range of thermodynamic parameters and mixture compositions. The present part of this series describes the preparatory stages of the
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Assessing the ignition and combustion of a kerosene droplet containing boron nanoparticles coated with polydopamine and polyvinylidene fluoride Combust. Flame (IF 4.4) Pub Date : 2024-03-12 Zhimin Fan, Zirui Qin, Tianze Deng, Jiyu Guo, Minxuan Li, Xiaoxi Yang, Bo Yin, Larry K.B. Li, Wen Ao
In this study, how the coating of polydopamine (PDA) and polyvinylidene fluoride (PVDF) on boron particles affects the ignition and combustion characteristics of kerosene droplets was investigated. In this work, PVDF was first coated onto boron nanoparticles using PDA as a binder to form double-coated composite particles (denoted as B@PF), and then the B@PF particles were blended into kerosene to produce
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Measurement of laminar burning speed at high pressures using plasma affected flame Combust. Flame (IF 4.4) Pub Date : 2024-03-11 James Shaffer, Omid Askari
Measurements of a propagating flame are crucial to the understanding and verification of important flame phenomena. Specifically, laminar, unstretched flame speed is desired to verify complex flame behavior such as turbulence or chemical kinetic models. This data is also necessary as advanced and more efficient combustion devices operate at these high pressures where this data is less reliable from
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Experimental and kinetic study of ammonia oxidation and NOx emissions at elevated pressures Combust. Flame (IF 4.4) Pub Date : 2024-03-11 Haochen Zhan, Shuming Li, Geyuan Yin, Erjiang Hu, Zuohua Huang
To investigate the effects of pressure and equivalence ratio on ammonia oxidation and the emission of NO, experiments were conducted in a flow reactor at atmospheric pressure and 5.0 MPa between 600 and 1250 K, with equivalence ratios ranging from 0.125 to 1.0. In addition, a kinetic model applicable to ammonia oxidation under high-pressure conditions was developed and validated against the performance
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Comparative radiative property measurements of single biomass and coal particles burning at high reactor temperatures Combust. Flame (IF 4.4) Pub Date : 2024-03-08 Yuan Yao, Aidin Panahi, Yiannis A. Levendis
This research measured the emissivity, temperature and soot loading of pulverized bituminous coal and three types of renewable biomass. Combustion occurred in a laboratory-scale drop tube furnace (DTF), where the fuels experienced high heating rates and ignited and burned in two distinct phases: devolatilization accompanied by volatile matter combustion in envelope flames, and sequential combustion
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The effect of finite molecular volume on the propagation of unsteady spherical flame front Combust. Flame (IF 4.4) Pub Date : 2024-03-07 Zifeng Weng, Yakun Zhang, Brian McN. Maxwell, Rémy Mével
An asymptotic analysis on the dynamics of adiabatic and nonadiabatic spherically expanding laminar flame was performed for real gas described by the Noble-Abel equation of state. The effect of the finite molecular volume was considered and characterized by a covolume parameter. It was demonstrated that the non-ideal model leads to higher flame speed at quasi-steady state and to lower Markstein number
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Numerical study on the shock wave and vortex and their coupling effect on the behavior of the flame induced by the spontaneous ignition of high-pressure hydrogen release Combust. Flame (IF 4.4) Pub Date : 2024-03-05 Liang Gong, Xianwen Zheng, Yifei Han, Tianyu Mo, Xufeng Yang, Yuchun Zhang
High-pressure hydrogen storage is currently the mainstream way of hydrogen storage. However, the risk of spontaneous ignition and subsequent jet flame are serious obstacles to the wide application of hydrogen energy. To further reveal the interaction of shock waves, vortices and flame induced by the spontaneous ignition of high-pressure hydrogen release under the effect of release process and burst
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Plasma-assisted ignition-stabilized combustion (PAISC): Benefits, limitations, and costs Combust. Flame (IF 4.4) Pub Date : 2024-03-04 Ravi Patel, Jeroen van Oijen, Sander Nijdam, Nico Dam
This work aims to find the benefits, limitations, and costs (in terms of plasma energy and NO emissions) of plasma-assisted ignition-stabilized combustion (PAISC). The experiments are performed on a custom-made methane-air jet flame burner with two coaxial flow inlets. Dielectric barrier discharge (DBD) configuration is set up in the outer flow channel which acts as four ignition sources. The DBDs
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Modeling of high-speed, methane-air, turbulent combustion, Part II: Reduced methane oxidation chemistry Combust. Flame (IF 4.4) Pub Date : 2024-03-04 Rui Xu, Sai Sandeep Dammati, Xian Shi, Ethan Samuel Genter, Zoltan Jozefik, Matthew E. Harvazinski, Tianfeng Lu, Alexei Y. Poludnenko, Venkateswaran Sankaran, Alan R. Kerstein, Hai Wang
A reduced, 12-species reaction model (FFCMy-12) is proposed for modeling high-speed turbulent methane flames at high Karlovitz numbers. The model was derived from an early development version (FFCMy) of the 119-species Foundational Fuel Chemistry Model Version 2.0. The reduction was carried out by combining direct species pruning, quasi-steady-state assumption, and reaction lumping, targeting a minimum
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Structural evolution of solid-fuel combustion using laser-induced breakdown spectroscopy and Raman spectroscopy Combust. Flame (IF 4.4) Pub Date : 2024-03-03 Wenkun Zhu, Mengfan Yuan, Christian Axt, Xiaohui Li, Anna Maßmeyer, Rui Sun
One of the major challenges regarding measuring chemical structures with laser-induced breakdown spectroscopy (LIBS) is that, it is difficult to track the source of organic components from atomic spectra since these structures have a similar elemental composition. However, LIBS molecular emissions (C, CN, etc.) provide a possibility to investigate these similar compositions. In the present study, an
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Impact of heat transfer due to fiber conduction, radiation and convection on the interpretation of experiments with isolated droplets Combust. Flame (IF 4.4) Pub Date : 2024-03-02 Mohamad Asrardel, Álvaro Muelas, Taha Poonawala, Javier Ballester
Isolated droplet setups have been extensively used during the last decades to characterize liquid fuel evaporation and combustion, being considered a reference framework approaching the simplest and idealized (canonical) configuration. However, in many cases, this configuration is affected by different experimental artifacts that may lead to non-negligible deviations from the assumed ideal conditions
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Analysis of weak secondary waves in a rotating detonation engine using large-eddy simulation and wavenumber-domain filtering Combust. Flame (IF 4.4) Pub Date : 2024-03-02 Guillaume Vignat, Davy Brouzet, Matthew Bonanni, Matthias Ihme
Rotating detonation engines (RDEs) are pressure-gain combustion devices which allow for a compact and mechanically simple engine design with improved thermodynamic efficiency compared to traditional deflagration devices. However, achieving these gains in practical devices that are operated with non-premixed reactants requires overcoming non-idealities in the mixing and combustion process. We investigate
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Forced ignition modeling of methane-ethylene mixtures in scramjet combustors Combust. Flame (IF 4.4) Pub Date : 2024-03-01 Shinichiro Ogawa, Kan Kobayashi, Sadatake Tomioka
To propose a design guideline for a scramjet combustor at low cost, an ignition model for a scramjet combustor is required. Therefore, the overall aim of this study was to propose an ignition model that could be used to estimate the forced ignition limits within a cavity. In this study, we developed two forced ignition models (FIMs): the forced ignition model in the recirculating zone (FIMR) and the
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Modeling of high-speed, methane–air, turbulent combustion, Part I: One-dimensional turbulence modeling with comparison to DNS Combust. Flame (IF 4.4) Pub Date : 2024-03-01 Zoltan Jozefik, Matthew E. Harvazinski, Venkateswaran Sankaran, Sai Sandeep Dammati, Alexei Y. Poludnenko, Tianfeng Lu, Alan R. Kerstein, Rui Xu, Hai Wang
The ability of the one-dimensional turbulence (ODT) model to serve as a surrogate direct numerical simulation (DNS) is assessed for highly turbulent flames. The ODT model is applied to freely propagating premixed methane–air flames at Karlovitz numbers 10, 10, 10, and 10, and results are compared with DNS. The ODT model solves the conservation equations for momentum, energy, and species on a one-dimensional
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Impact of flash boiling spray on soot generation of a rich fuel–air mixture under various ambient pressures Combust. Flame (IF 4.4) Pub Date : 2024-02-29 Mingli Cui, Weixuan Zhang, Jinhong Fu, Xulin Luo, David L.S. Hung, Min Xu, Xuesong Li
Particulate emission is one of the critical challenges for the modern gasoine direct injection (GDI) engines. Especially under cold start conditions, the global equivalence ratio inside the cylinder is often set quite rich, leading to the generation of a large amount of soot. The fuel distribution state, such as homogeneous mixing and heterogeneous mixing with local rich pockets prior to the combustion
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A machine learning method to predict rate constants for various reactions in combustion kinetic models Combust. Flame (IF 4.4) Pub Date : 2024-02-28 Ning Li, Sanket Girhe, Mingzhi Zhang, Bingjie Chen, Yingjia Zhang, Shenghua Liu, Heinz Pitsch
Accurate prediction of temperature-dependent reaction rate constants is essential for the development of combustion kinetic models. However, the computational expense associated with calculating rate constants using high-level quantum chemistry methods becomes infeasible as the complexity of the kinetic models grows, and alternative approaches relying on analogies can exhibit significant inaccuracies
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Ignition characteristics of single coal particles under ammonia co-firing conditions Combust. Flame (IF 4.4) Pub Date : 2024-02-27 Chenlin Chen, Zhihua Wang, Yong He, Wubin Weng, Kefa Cen
To meet the goal of an international carbon-neutral framework, the promotion of clean coal utilization occupies a vital position in reducing greenhouse gas emissions. Ammonia co-firing is considered as a potential strategy for future power generation to reduce fossil energy consumptions, soot, CO emissions, and hydrocarbon pollutants. In the present work, the ignition characteristics of single coal
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Effect of AP coating or blending on the ignition and combustion of Al particles under a high-pressure water vapour–Ar environment Combust. Flame (IF 4.4) Pub Date : 2024-02-27 Peihui Xu, Xingang Dong, Wenke Zhang, Yuxin Yang, Xueqin Liao, Jianzhong Liu
Overcoming the difficulty of ignition and combustion of aluminium in water vapour is the key to being applied in underwater propellant applications. The effect of coating or blending 20 mass% ammonium perchlorate (namely, AP@Al or AP–Al samples) on the ignition and combustion of Al particles in a 1.0 MPa water vapour–Ar environment was investigated using a constant temperature pressurized combustion
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The effect of the unsaturation degree on the gas-phase autoignition of methyl oleate and methyl linoleate: Experimental and modeling study Combust. Flame (IF 4.4) Pub Date : 2024-02-27 Wei Zhou, Zimu Wang, Yueying Liang, Xiaoqin Zhang, Liang Yu, Xingcai Lu
As the product of transesterification between various oils and alcohols, biodiesel exhibits characteristics of renewability and a wide range of raw materials. The ignition delay times (IDTs) of methyl oleate (MEOLE) and methyl linoleate (MLINO), the primary constituents of biodiesels, were measured in a heated rapid compression machine (RCM) to investigate the impact of CC double bond on the reactivity
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New discovery of aluminium agglomeration in composite solid propellants based on microscopic heating system Combust. Flame (IF 4.4) Pub Date : 2024-02-23 Shipo Li, Zhan Wen, Lu Liu, Xiang Lv, Peijin Liu, Bo Yin, Larry K.B. Li, Wen Ao
The amount of energy delivered to a solid-fueled rocket motor is its most crucial performance indicator. Metallic fuels, such as aluminum, is commonly added to propellants for obtaining high energy densities. In this study, the agglomeration of four distinct types of composite solid propellants, comprising different adhesives, oxidants, and Al particles, during gradual heating was experimentally investigated
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Air humidity influence on combustion of R-1234yf (CF3CFCH2), R-1234ze(E) (trans-CF3CHCHF) and R-134a (CH2FCF3) refrigerants Combust. Flame (IF 4.4) Pub Date : 2024-02-23 Valeri I. Babushok, Gregory T. Linteris
The influence of air humidity on flame propagation in mixtures of hydrofluorocarbons (HFCs) with air was studied through numerical simulations and comparison with measurements from the literature. Water vapor added to the air in mixtures of fluorine rich hydrofluorocarbons (F/H ≥ 1) can be considered as a fuel additive that increases the production of radicals (H, O, OH) and increases the overall reaction
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Experimental and modeling study of NO2 addition effects on autoignition behavior of propylene Combust. Flame (IF 4.4) Pub Date : 2024-02-21 Fuquan Deng, Xinbo Huang, Song Cheng, Yingjia Zhang, Zuohua Huang, Hui Tang, Hongtao Zheng, Xiao Liu
Autoignition behaviors of NO/CH/O/Ar mixtures with the blending ratio of [NO]/[CH] ranging from 0 % to 100 % were measured at pressure of 2.03E+5 - 1.01E+6 Pa, temperature of 950 – 1820 K, and equivalence ratio of 0.5 – 2.0 in a high-pressure shock tube. NO blending effects are characterized through changes in ignition delay times. Experiments indicate the strong promoting effect of NO on the reactivity
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Effects of droplet evaporation on negative temperature coefficient phenomenon and a prediction model for two-stage auto-ignition Combust. Flame (IF 4.4) Pub Date : 2024-02-19 Yu Zhang, Cheng Cheng, Quanqing Zhang, Shijie Xu, Taotao Zhou, Chunmei Wang, Yejian Qian
The effects of droplet evaporation on two-stage auto-ignition are investigated by embedding evaporation source terms into a gaseous homogeneous reactor. The ranges of pressure, temperature, equivalence ratio and droplet diameter are 5–15 bar, 600–1000 K, 0.25–1.5 and 0–100 μm, respectively. Evaporation Damkholer number () is proposed to investigate two-stage auto-ignition and its increase affects two-stage
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Simulations of flaming combustion and flaming-to-smoldering transition in wildland fire spread at flame scale Combust. Flame (IF 4.4) Pub Date : 2024-02-19 Mohamed Mohsen Ahmed, Arnaud Trouvé, Jason Forthofer, Mark Finney
Our objective in the present study is to provide basic insights into the coupling between external-gas and solid biomass vegetation processes that control the dynamics of flame spread in wildland fire problems. We focus on a modeling approach that resolves processes occurring at vegetation and flame scales, , the formation of flammable vapors due to the thermal degradation of the solid biomass, the
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Exploration on the combustion chemistry of p-xylene: A comprehensive study over wide conditions and comparison among C8H10 isomers Combust. Flame (IF 4.4) Pub Date : 2024-02-17 Yuwen Deng, Wenhao Yuan, Sandro Gaïl, Wei Li, Long Zhao, Jiuzhong Yang, Fei Qi, Yuyang Li, Philippe Dagaut
Pyrolysis and oxidation of -xylene over wide conditions were studied in this work in order to provide a comprehensive insight into the combustion chemistry of -xylene. Concerning this goal, the pyrolysis of -xylene was investigated in a flow reactor at pressures from 0.04 to 1 atm over the temperature range of 1000–1600 K. Key radicals, isomers and PAH products including three xylyl isomers, benzyl
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Linear and non-linear stability of gaseous detonation at elevated pressure Combust. Flame (IF 4.4) Pub Date : 2024-02-16 Zifeng Weng, Rémy Mével
The stability of detonation propagation at elevated pressure was investigated via linear stability analysis and numerical simulation in one dimension. The effect of finite molecular volume neglected in perfect gas was accounted for with a real gas model based on the Noble-Abel equation of state and was characterized with a non-dimensional covolume parameter (). The neutral stability boundary was derived
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Optimization effect and reaction mechanism of flake aluminum powder on the combustion performance of high-energy-density JP-10/PO composite fuel Combust. Flame (IF 4.4) Pub Date : 2024-02-15 Yuntao Li, Zelin Wu, Qi Jing, Laibin Zhang, Dan Wang, Qingming Liu, Sheng Qi, Houjia Xu, Yueyang Li
JP-10 is a high-density hydrocarbon fuel known for its exceptional comprehensive properties and wide usage in scramjets and detonation engines. Previous research has successfully enhanced the ignition susceptibility and reduced the concentration of incomplete combustion products in JP-10 liquid fuel through the inclusion of diethyl ether (DEE) and propylene oxide (PO). However, it is worth mentioning
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Combustion behavior of aluminized metal iodate composites. Part 1: Decomposition mechanism of metal iodates Combust. Flame (IF 4.4) Pub Date : 2024-02-15 Yujie Wang, Keren Shi, George Issac Paul, Prithwish Biswas, Michael R. Zachariah
Metal iodates are candidates of high temperature biocidal oxidizing agents owing to their high iodine and oxygen content. Here we explore the high temperature decomposition mechanism of alkali and alkaline metal iodates (LiIO, NaIO, KIO, Mg(IO), and Ca(IO)). Temperature-jump/time-of-flight mass spectrometry (T-Jump/TOFMS) measurements reveal that while all of these iodates release O, only Mg(IO), Ca(IO)
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Analysis of the influence of the type of heat transfer on the dynamics of the ignition processes of wood biomass particles under complex heating conditions Combust. Flame (IF 4.4) Pub Date : 2024-02-15 G.V. Kuznetsov, S.V. Syrodoy, Zh.A. Kostoreva, N.A. Nigay, M.V. Purin, V.A. Karelin, V.V. Salomatov
The article presents the results of theoretical and experimental studies of the processes of wood particles ignition under heating conditions typical for furnace devices operating using the circulating fluidized bed technology. The characteristics and conditions of ignition processes under radiation, radiation-convective and radiation-convective-microwave heating are compared. According to the results
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Experimental study on the effect of pressure on single and two stage combustion of decomposed ammonia (NH3 H2 N2) blends over a swirl stabilized burner Combust. Flame (IF 4.4) Pub Date : 2024-02-15 Mario Ditaranto, Inge Saanum
Ammonia (NH) is a practical hydrogen vector for gas turbine power generation, but struggles to be deployed commercially due to many unresolved technical and fundamental challenges. This experimental investigation focuses on combustion of fuel blends representatives of various NH decomposition (or cracking) ratios in a combustor fitted with a swirl-stabilized burner, exploring pressures ranging from
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Kinetic study of H-abstraction and preliminary pyrolysis of n-decane in post-injection fuels Combust. Flame (IF 4.4) Pub Date : 2024-02-14 Pan Wang, Jia Yan, Tong Yan, Chengcheng Ao, Lidong Zhang, Lili Lei
The combustion and pyrolysis process of n-decane was investigated via quantum chemical method to enhance the understanding of post-injection fuels. The hydrogen abstraction reactions were the main reactions that initiated combustion and pyrolysis of n-decane via H atoms and CH/OH/NO radicals. The potential energy surface of hydrogen abstraction and preliminary pyrolysis was determined via high precision
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Combustion behavior of aluminized metal iodate composites. Part 2: Iodine and energy release rate Combust. Flame (IF 4.4) Pub Date : 2024-02-14 Yujie Wang, George Issac Paul, Erik Hagen, Haiyang Wang, Michael R. Zachariah
Metal iodates are attractive oxidizers in the biocidal application due to their high oxygen and iodine content. In this study, we systematically investigate the iodine release, ignition, and reactivity of aluminized alkali and alkaline metal iodate thermites, namely Al-Mg(IO), Al-Ca(IO), Al-LiIO, Al-NaIO and Al-KIO, as well as the combustion behavior of assembled high-loading aluminized metal iodate
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Temperature measurement on condensed combustion products of magnesium with oxygen and water vapor Combust. Flame (IF 4.4) Pub Date : 2024-02-13 Keita Nishii, Hiroyuki Koizumi
This study investigated the behavior and temperature of condensed combustion products (CCPs) in a magnesium–water vapor flame. The experiments were conducted using magnesium plates with a surface area of and an oxidizer pressure in the range of 10–100 kPa, in consideration of potential applications in microspacecraft. Compared with the air and oxygen cases, a substantial quantity of white residue remained
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Dependence of ignition delay time on its definition − A case study on methane ignition Combust. Flame (IF 4.4) Pub Date : 2024-02-13 Boyang Su, Máté Papp, Peng Zhang, Tamás Turányi
Ignition delay time (IDT, ) is the time period from the onset of a given temperature and pressure of a combustible gas mixture to the time of ignition. The time point of ignition is defined as reaching a given condition of pressure, temperature, or one of the species concentrations. In measurements, ignition of hydrocarbons and oxygenates is usually detected based on monitoring the change of pressure
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Hybrid rich- and lean-premixed ammonia-hydrogen combustion for mitigation of NOx emissions and thermoacoustic instabilities Combust. Flame (IF 4.4) Pub Date : 2024-02-12 Ukhwa Jin, Kyu Tae Kim
The large-scale direct utilization of two carbon-free fuels, ammonia and hydrogen, is currently attracting significant interest in the context of the development of new gas turbine combustion technologies, with paying close attention to the reduction of nitrogen oxides and unburned ammonia emissions. Motivated by recent observations that rich-premixed conditions tend to mitigate excessive NOx emissions
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Experimental and chemical kinetic modeling study of ethylene carbonate oxidation: A lithium-ion battery electrolyte surrogate model Combust. Flame (IF 4.4) Pub Date : 2024-02-12 Keisuke Kanayama, Claire M. Grégoire, Sean P. Cooper, Yousef Almarzooq, Eric L. Petersen, Olivier Mathieu, Kaoru Maruta, Hisashi Nakamura
Fire-risk assessment of lithium-ion batteries (LIBs) is an urgent task as the number and size of products using LIBs are both increasing. LIB electrolyte solvents consist of mixtures of flammable carbonate esters, such as ethylene carbonate (EC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), and diethyl carbonate (DEC). This study aims to report the first EC combustion experiments (ignition
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The high-temperature ignition kinetics of nitroethane: A shock-tube experimental and kinetic modeling study Combust. Flame (IF 4.4) Pub Date : 2024-02-10 Jinhu Liang, Xinhui Wang, Chen Zhao, Ziwen Zhao, Yang Zhang, Qian Yao, Ming-Xu Jia, Guojun Kang, Siyu Xu, Fengqi Zhao, Quan-De Wang, Henry J. Curran
Nitroethane is a representative nitro-containing energetic molecule, and is considered to be a potential propellant and a fuel additive. Thus, understanding its combustion characteristics and chemistry is critical in the development of hierarchical kinetic models of nitro-containing energetic materials. Herein, we investigate the high-temperature ignition kinetics of nitroethane via experimental measurements
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Uncertainty quantification and sensitivity analysis of an unsteady axisymmetric reacting solid particle Combust. Flame (IF 4.4) Pub Date : 2024-02-10 A. Hassan, L. Schumacher, M. Sabry, V. Le Chenadec, T. Sayadi
Simulations of unsteady solid fuel particle combustion involve a variety of complex phenomena, which can be numerically predicted using models with varying levels of fidelity. These models in turn rely on parameters obtained from experiments or small-scale simulations. It is therefore essential to quantify the uncertainties in the prediction of different quantities of interest with respect to these
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Water vapor on microwave-enhanced spark ignition of CH4-air flame: Experimental and numerical analysis Combust. Flame (IF 4.4) Pub Date : 2024-02-09 Xinhua Zhang, Zhaowen Wang, Huimin Wu, Jyh-Yuan Chen, Xiaobei Cheng
To enrich the understanding of Microwave Assisted spark Ignition (MAI) under water dilution, this work investigated the early flame development, plasma jet formation, and energy deposition during the MAI through the ignition experiments of methane-air under 0 %∼25 % water contents () and 0.6∼1.0 equivalence ratios (φ). Furthermore, a two-temperature well-mixed reactor together with a detailed mechanism
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Unveiling high-temperature oxidation kinetics of PODE2: Theoretical studies on the H-abstraction, isomerization, and β-dissociation reactions Combust. Flame (IF 4.4) Pub Date : 2024-02-09 Zhe Ren, Chao Zhou, Zeyan Qiu, Yaozong Duan, Dong Han
Polyoxymethylene dimethyl ether (PODE) is a promising fuel additive to reduce soot emissions. In this work, a theoretical study on the H-abstraction reaction from PODE (CHOCHOCHOCH) by the H atom and CH radical, as well as the subsequent isomerization and β-dissociation reactions of PODE radicals were carried out. The geometry optimization and frequency analysis for all the stationary points on the
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Experimental and modeling study on oxidation of n-decane and its mixtures with 1,2,4-trimethylbenzene Combust. Flame (IF 4.4) Pub Date : 2024-02-08 Yilun Liang, Cong Wang, Fanggang Zhang, Mo Yang, Song Guo, Juan Wang
Paraffins and aromatics are the two most important components of surrogate, both for conventional jet fuel and alternative fuel. To investigate the interaction between paraffins and aromatics, oxidation experiments were carried out in this work for three fuel groups including neat -decane, 90 % -decane/10 % 1,2,4-trimethylbenzene (124TMB) mixture and 80 % -decane/20 % 124TMB mixture by mole. An atmospheric
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Multichannel kinetics of methoxymethyl + O2 in combustion Combust. Flame (IF 4.4) Pub Date : 2024-02-07 Qian Zhao, Wuchuan Sun, Yingjia Zhang, Zuohua Huang
Organic peroxy radicals (RȮ), formed by association reaction of Ṙ + O, are important intermediates in low-temperature combustion of hydrocarbon fuels. A fate of RȮ is isomerize to QOOH, and the downstream reactions of QOOH are known to profoundly fuel reactivity. However, both experimental measurements and high-level theoretical calculations of RȮ kinetics are scarce, leading to a large gap in our
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Scramjet cavity ignition using nanosecond-pulsed high-frequency discharges Combust. Flame (IF 4.4) Pub Date : 2024-02-07 Timothy M. Ombrello, Stephen D. Hammack, Campbell D. Carter, Kenneth Busby, Joseph K. Lefkowitz
Ignition of an ethylene-fueled cavity in Mach-2 flow was performed using nanosecond-pulsed high-frequency discharges (NPHFDs) over a range of pulse repetition frequencies (PRF = 1.5–300 kHz). The energy deposition rate and duration were controlled to be commensurate with the temporal and spatial fluctuations of velocity and fuel concentration within a cavity-based flame holder to enhance the ignition
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Cross-effect considered skeletal chemical mechanism construction for primary reference fuel/oxymethylene ethers blends using radical trace and sensitivity analysis Combust. Flame (IF 4.4) Pub Date : 2024-02-07 Shuai Huang, Yachao Chang, Ming Jia, Xu Han, Hu Wang
Oxymethylene ethers (OME = 1–6) are a class of synthetic liquid fuels that carry a great potential to reduce carbon dioxides (CO) and particle matter emissions. However, the lower heating value of all OME is inferior to conventional diesel fuel, hindering their applications in compression-ignition engines. Instead, their utilizations as diesel additives have attracted considerable attention. Unfortunately
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A comprehensive experimental and kinetic modeling study of p-cymene oxidation Combust. Flame (IF 4.4) Pub Date : 2024-02-06 Mingxia Liu, Mengyuan Wang, Chih-Jen Sung, Khalid Aljohani, Aamir Farooq, Nathan Lindblade, Claire M. Grégoire, Olivier Mathieu, Eric L. Petersen, Henry J. Curran, Chong-Wen Zhou
-Cymene is a renewable terpenoid bio-aromatic species that is a promising aromatic substitute for conventional transportation fuel. A comprehensive experimental and kinetic investigation of -cymene pyrolysis and oxidation is undertaken in this study over a wide range of engine-relevant conditions. Ignition delay times are measured in a rapid compression machine at pressures of 20, 30, and 40 atm, at
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An Arbitrary Lagrangian–Eulerian framework for the consistent analysis of entropy wave generation Combust. Flame (IF 4.4) Pub Date : 2024-02-03 Moritz Merk, Alexander J. Eder, Wolfgang Polifke
Entropy waves are generated in many technically relevant flow processes such as combustion, mixing, or convective heat transfer. When accelerated, entropy waves generate acoustic waves that contribute to the overall sound emission and can lead to self-excited thermoacoustic instabilities, especially at low frequencies. In order to reduce or prevent these undesirable byproducts of the flow, an understanding
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Toward improved ion chemistry in flames: revisiting C3H3+ reaction pathways and mechanism validation against mass spectrometric measurements in non-sooting premixed flames of small aliphatic hydrocarbons Combust. Flame (IF 4.4) Pub Date : 2024-02-03 Andrey V. Cherepanov, Vitaly G. Kiselev, Artem M. Dmitriev, Andrey G. Shmakov, Denis A. Knyazkov
While the neutral combustion chemistry of hydrocarbon fuels is nowadays relatively well established, there is a growing demand for the reliable kinetic models including ion-molecular reactions. In this work, we present an updated ion chemistry model for the flames of small hydrocarbons. It is built upon the mechanism reported recently (Knyazkov et al., Proc. Combust. Inst., 2023) with the improved
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Finding a common ground for RCM experiments. Part B: Benchmark study on ethanol ignition Combust. Flame (IF 4.4) Pub Date : 2024-02-03 R.D. Büttgen, M. Preußker, D. Kang, S. Cheng, S.S. Goldsborough, G. Issayev, A. Farooq, H. Song, Y. Fenard, G. Vanhove, A. Abd El-Sabor Mohamed, H.J. Curran, K.A. Heufer
Rapid compression machines (RCMs) are widely used to investigate gas phase reaction kinetics of various kind of fuels at application relevant conditions. In principle, the operation of an RCM is based on the idea of compressing a homogenous pre-mixed fuel-air mixture by a piston. Usually creviced pistons ensure a homogenous adiabatic core in the center of the reaction chamber which permits the assumption
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Identifying a combination of intermetallic and thermite reactions that result in a non-expanding compact Combust. Flame (IF 4.4) Pub Date : 2024-02-03 Amee L. Polk, Steven W. Dean, Michael R. Flickinger, Kerri-lee A. Chintersingh, Dakota G. Scott, Erica R. Valdes, Kyle R. Fisher, Timothy P. Weihs
We investigate low gas generating, thermite formulations composed of ball-milled Al-Zr fuel and TiO (anatase) oxide powders combined in a stoichiometric ratio. These thermite materials have applications as heat sources in confined geometries where gas generation and sample expansion would be detrimental. In this study, we identify the processing conditions that yield the most reactivity and the least