Pub Date : 2024-05-31DOI: 10.1016/j.combustflame.2024.113527
Zhaoming Mai , Yingtao Wu , Chenglong Tang , Haibao Mu , Wei Wang , Zuohua Huang
In this study, novel ignition delay times (IDTs) were experimentally measured for the n-dodecane/methane binary mixture with various n-dodecane content at the range of 5–20 bar and 600–1000 K, utilizing a heated rapid compression machine (RCM). Subsequently, a chemical kinetic model was developed for n-dodecane/methane binary mixture and widely validated by the experimental data including ignition delay times, laminar flame speeds, and speciation evolution in this study and the literature. The present model shows good predictive performance and was further applied in the kinetic analysis of the n-dodecane/methane binary mixture ignition characteristic. The results highlight a significant reactivity-promoting effect on the IDTs with the addition of n-dodecane through the low-temperature oxidation processes. This promoting effect is nonlinear and particularly notable in the NTC region. Additionally, the dilution gas component significantly influences the total IDTs at low-to-intermediate temperature conditions but shows less impact on the first-stage IDTs. The chemical effect of the dilution gas is minor at low-temperature conditions, while the thermodynamic effect plays a more important role in influencing the IDTs of the binary mixture.
{"title":"Ignition delay time measurements and kinetic modeling for n-dodecane and methane blends at low-to-intermediate temperature conditions","authors":"Zhaoming Mai , Yingtao Wu , Chenglong Tang , Haibao Mu , Wei Wang , Zuohua Huang","doi":"10.1016/j.combustflame.2024.113527","DOIUrl":"10.1016/j.combustflame.2024.113527","url":null,"abstract":"<div><p>In this study, novel ignition delay times (IDTs) were experimentally measured for the n-dodecane/methane binary mixture with various n-dodecane content at the range of 5–20 bar and 600–1000 K, utilizing a heated rapid compression machine (RCM). Subsequently, a chemical kinetic model was developed for n-dodecane/methane binary mixture and widely validated by the experimental data including ignition delay times, laminar flame speeds, and speciation evolution in this study and the literature. The present model shows good predictive performance and was further applied in the kinetic analysis of the n-dodecane/methane binary mixture ignition characteristic. The results highlight a significant reactivity-promoting effect on the IDTs with the addition of n-dodecane through the low-temperature oxidation processes. This promoting effect is nonlinear and particularly notable in the NTC region. Additionally, the dilution gas component significantly influences the total IDTs at low-to-intermediate temperature conditions but shows less impact on the first-stage IDTs. The chemical effect of the dilution gas is minor at low-temperature conditions, while the thermodynamic effect plays a more important role in influencing the IDTs of the binary mixture.</p></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141194180","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-31DOI: 10.1016/j.combustflame.2024.113526
Yakun Zhang, Zifeng Weng, Rémy Mével
The propagation of laminar oxy-syngas and oxy-methane flames diluted by supercritical carbon dioxide was numerically simulated for the planar flame configuration under the conditions related to the operation of oxy-combustor in the direct-fired power cycle. Because of the extremely high pressure typically used for such an application, real fluid models were considered for the equation of state, thermodynamic functions, transport properties, as well as the mass action law. Numerical results show that the relative uncertainty on the flame speed caused by real gas effects and by different chemical mechanisms can be on the same order of magnitude for oxy-syngas combustion. For oxy-methane combustion, the deviation of the flame speed between the predictions of different mechanisms is much more significant than that caused by real gas effects. The effects of various non-ideal effects were explored progressively. Including the real gas equation of state and thermodynamic functions reduces the adiabatic flame temperature, and thus the flame speed is decreased. Adopting transport properties of real gas and including revisions on the mass action law and equilibrium constant would both increase the flame speed. Inhibition and promotion of flame propagation resulting from the effects of inter-molecular attraction and finite molecular volume were also identified and analyzed.
Novelty and Significance Statement
1. Supercritical laminar flame speed was systematically simulated with complete real gas model to quantify the non-ideal effects under direct-fired power cycle relevant conditions.
2. The individual impact of components in the real gas model on the flame speed were determined and represented with key parameters.
3. The uncertainties on laminar flame speed caused by reaction mechanism and real gas effects were compared and found to be on the same order of magnitude under certain conditions.
{"title":"Laminar flame speeds of supercritical CO2 diluted oxy-syngas and oxy-methane flames under direct-fired power cycle relevant conditions","authors":"Yakun Zhang, Zifeng Weng, Rémy Mével","doi":"10.1016/j.combustflame.2024.113526","DOIUrl":"10.1016/j.combustflame.2024.113526","url":null,"abstract":"<div><p>The propagation of laminar oxy-syngas and oxy-methane flames diluted by supercritical carbon dioxide was numerically simulated for the planar flame configuration under the conditions related to the operation of oxy-combustor in the direct-fired power cycle. Because of the extremely high pressure typically used for such an application, real fluid models were considered for the equation of state, thermodynamic functions, transport properties, as well as the mass action law. Numerical results show that the relative uncertainty on the flame speed caused by real gas effects and by different chemical mechanisms can be on the same order of magnitude for oxy-syngas combustion. For oxy-methane combustion, the deviation of the flame speed between the predictions of different mechanisms is much more significant than that caused by real gas effects. The effects of various non-ideal effects were explored progressively. Including the real gas equation of state and thermodynamic functions reduces the adiabatic flame temperature, and thus the flame speed is decreased. Adopting transport properties of real gas and including revisions on the mass action law and equilibrium constant would both increase the flame speed. Inhibition and promotion of flame propagation resulting from the effects of inter-molecular attraction and finite molecular volume were also identified and analyzed.</p><p><strong>Novelty and Significance Statement</strong></p><p>1. Supercritical laminar flame speed was systematically simulated with complete real gas model to quantify the non-ideal effects under direct-fired power cycle relevant conditions.</p><p>2. The individual impact of components in the real gas model on the flame speed were determined and represented with key parameters.</p><p>3. The uncertainties on laminar flame speed caused by reaction mechanism and real gas effects were compared and found to be on the same order of magnitude under certain conditions.</p></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141194251","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-30DOI: 10.1016/j.combustflame.2024.113408
Gregor Doehner, Alexander J. Eder, Camilo F. Silva
In this work, we present a parsimonious set of ordinary differential equations (ODEs), describing with good precision and over a wide range of frequencies the linear and nonlinear dynamics of different types of fully premixed, turbulent, swirl-stabilized flames. This phenomenological model comprises eight ODEs and can physically be interpreted as a superposition of two mass–spring–damper systems.
The model is characterized by 11 parameters and one nonlinear term of structure in particular, with position and rate of displacement of a given oscillator mass. The model can be optimized in frequency domain or in time domain. The former is suitable for situations where experimental data of the flame transfer function (FTF) and flame describing function (FDF) are available. The latter is suitable for situations where time series (input and output) from numerical simulations or experiments are available. In the present work, large eddy simulation (LES) data is used.
Choosing a model comprising ODEs enables us to describe the dynamics of the flame using linear and nonlinear input-to-output transformations via the states. This is a sharp contrast to commonly applied finite impulse response (FIR) models, which can only directly employ nonlinear functions acting on the input or output — not on derivatives or other states of the underlying dynamical system. We demonstrate the simplicity of implementing our model by investigating the coupling of a time-domain acoustic solver with the set of ODEs proposed, all within the graphical interface of Simulink. The nonlinearity plays a crucial role in achieving good agreement in the nonlinear regime, as observed in the FDF, as well as in both the amplitude and frequency of the investigated limit cycle, which exhibits a simple period-one oscillation. However, there is still room for improvement in the nonlinear model if more complex dynamics need to be modeled, thanks to the flexible ODE structure proposed in this work.
Novelty and significance
A phenomenological model, characterized by a parsimonious set of ordinary differential equations is presented. This model is able to describe the dynamic flame response of typical turbulent, swirl-stabilized flames to acoustic disturbances in their linear and nonlinear regime. The model can be calibrated from broadband time series data or reference frequency domain data. After calibration, the model can be coupled to an acoustic network to predict the occurrence of limit cycle
{"title":"A parsimonious system of ordinary differential equations for the response modeling of turbulent swirled flames","authors":"Gregor Doehner, Alexander J. Eder, Camilo F. Silva","doi":"10.1016/j.combustflame.2024.113408","DOIUrl":"10.1016/j.combustflame.2024.113408","url":null,"abstract":"<div><p>In this work, we present a parsimonious set of ordinary differential equations (ODEs), describing with good precision and over a wide range of frequencies the linear and nonlinear dynamics of different types of fully premixed, turbulent, swirl-stabilized flames. This phenomenological model comprises eight ODEs and can physically be interpreted as a superposition of two mass–spring–damper systems.</p><p>The model is characterized by 11 parameters and one nonlinear term of structure <span><math><mrow><mi>β</mi><msup><mrow><mi>x</mi></mrow><mrow><mn>2</mn></mrow></msup><mover><mrow><mi>x</mi></mrow><mrow><mo>̇</mo></mrow></mover></mrow></math></span> in particular, with position <span><math><mi>x</mi></math></span> and rate of displacement <span><math><mover><mrow><mi>x</mi></mrow><mrow><mo>̇</mo></mrow></mover></math></span> of a given oscillator mass. The model can be optimized in frequency domain or in time domain. The former is suitable for situations where experimental data of the flame transfer function (FTF) and flame describing function (FDF) are available. The latter is suitable for situations where time series (input and output) from numerical simulations or experiments are available. In the present work, large eddy simulation (LES) data is used.</p><p>Choosing a model comprising ODEs enables us to describe the dynamics of the flame using linear <em>and</em> nonlinear input-to-output transformations via the states. This is a sharp contrast to commonly applied finite impulse response (FIR) models, which can only directly employ nonlinear functions acting on the input or output — not on derivatives or other states of the underlying dynamical system. We demonstrate the simplicity of implementing our model by investigating the coupling of a time-domain acoustic solver with the set of ODEs proposed, all within the graphical interface of Simulink. The <span><math><mrow><msup><mrow><mi>x</mi></mrow><mrow><mn>2</mn></mrow></msup><mover><mrow><mi>x</mi></mrow><mrow><mo>̇</mo></mrow></mover></mrow></math></span> nonlinearity plays a crucial role in achieving good agreement in the nonlinear regime, as observed in the FDF, as well as in both the amplitude and frequency of the investigated limit cycle, which exhibits a simple period-one oscillation. However, there is still room for improvement in the nonlinear model if more complex dynamics need to be modeled, thanks to the flexible ODE structure proposed in this work.</p><p><strong>Novelty and significance</strong></p><p>A phenomenological model, characterized by a parsimonious set of ordinary differential equations is presented. This model is able to describe the dynamic flame response of typical turbulent, swirl-stabilized flames to acoustic disturbances in their linear and nonlinear regime. The model can be calibrated from broadband time series data or reference frequency domain data. After calibration, the model can be coupled to an acoustic network to predict the occurrence of limit cycle","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0010218024001172/pdfft?md5=45bc573d389e7e512412eb3aece6ce2e&pid=1-s2.0-S0010218024001172-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141194178","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-30DOI: 10.1016/j.combustflame.2024.113529
Jinguo Sun, Yupan Bao, Jonas Ravelid, Alexander A. Konnov, Andreas Ehn
In the emerging field of plasma-assisted ammonia (NH3) combustion, the evolution of key intermediate species has rarely been reported. This work establishes a simultaneous measurement system of laser-induced fluorescence (LIF) for hydroxyl (OH) and quantitative two-photon-absorption LIF for atomic oxygen (O), to explore the OH and O dynamics in an NH3/air flame affected by a nanosecond (ns) pulsed plasma discharge. Firstly, with the plasma on, the molar fraction of O is quantified to reach 8.7 × 10–3 in the burnt zone, about two orders of magnitude higher than that without plasma. In addition, the OH LIF signal intensity is four times higher, indicating a significant kinetic enhancement. Then, the spatial characteristics of OH and O are discussed and compared, showing remarkable discrepancy. The discrepancy between them indicates that O production is dominated by plasma kinetics, however, the OH production, primarily stemming from reactions between O and NH3/H2O, still depends on parameters associated with combustion kinetics. We further study the temporal dynamics of O and OH. It is concluded that O and OH peaks at 1.75 μs are mainly attributed to the pathway of quenching of the excited species. After that, O and OH start to decay but show significant differences between unburnt and burnt zones, which are characterized by a single-exponential decay and a bi-exponential decay, respectively. In the unburnt zone, the OH decay is much slower than the O decay due to the diverse pathways for OH production. In the burnt zone, the bi-exponential decay of O and OH can essentially be regarded as a process in which the NH3/air reactive system reaches chemical equilibrium. At this stage, the impacts of the excited species from the plasma gradually diminish and combustion kinetics dominates alone.
在等离子体辅助氨（NH）燃烧这一新兴领域，很少有关于关键中间物种演变的报道。这项研究建立了一个同时测量羟基（OH）激光诱导荧光（LIF）和原子氧（O）定量双光子吸收 LIF 的系统，以探索纳秒（ns）脉冲等离子体放电影响的 NH/ 空气火焰中羟基和 O 的动态。首先，在等离子体开启的情况下，灼烧区中 O 的摩尔分数达到 8.7 × 10，比未开启等离子体时高两个数量级。此外，OH LIF 信号强度高出四倍，表明动力学增强效果显著。然后，对 OH 和 O 的空间特征进行了讨论和比较，结果显示两者之间存在显著差异。它们之间的差异表明，O 的产生主要受等离子体动力学的支配，而主要来自 O 和 NH/HO 反应的 OH 的产生仍然取决于与燃烧动力学相关的参数。我们进一步研究了 O 和 OH 的时间动态。结论是，1.75 μs 时的 O 和 OH 峰值主要归因于激发物种的淬火途径。此后，O 和 OH 开始衰减，但在未燃烧区和燃烧区之间存在显著差异，分别表现为单指数衰减和双指数衰减。在未燃烧区，由于产生 OH 的途径不同，OH 的衰减比 O 的衰减慢得多。在燃烧区，O 和 OH 的双指数衰减基本上可以看作是 NH/空气反应系统达到化学平衡的过程。在这个阶段，来自等离子体的激发物种的影响逐渐减弱，燃烧动力学单独占据主导地位。
{"title":"Plasma-assisted NH3/air flame: Simultaneous LIF measurements of O and OH","authors":"Jinguo Sun, Yupan Bao, Jonas Ravelid, Alexander A. Konnov, Andreas Ehn","doi":"10.1016/j.combustflame.2024.113529","DOIUrl":"10.1016/j.combustflame.2024.113529","url":null,"abstract":"<div><p>In the emerging field of plasma-assisted ammonia (NH<sub>3</sub>) combustion, the evolution of key intermediate species has rarely been reported. This work establishes a simultaneous measurement system of laser-induced fluorescence (LIF) for hydroxyl (OH) and quantitative two-photon-absorption LIF for atomic oxygen (O), to explore the OH and O dynamics in an NH<sub>3</sub>/air flame affected by a nanosecond (ns) pulsed plasma discharge. Firstly, with the plasma on, the molar fraction of O is quantified to reach 8.7 × 10<sup>–3</sup> in the burnt zone, about two orders of magnitude higher than that without plasma. In addition, the OH LIF signal intensity is four times higher, indicating a significant kinetic enhancement. Then, the spatial characteristics of OH and O are discussed and compared, showing remarkable discrepancy. The discrepancy between them indicates that O production is dominated by plasma kinetics, however, the OH production, primarily stemming from reactions between O and NH<sub>3</sub>/H<sub>2</sub>O, still depends on parameters associated with combustion kinetics. We further study the temporal dynamics of O and OH. It is concluded that O and OH peaks at 1.75 μs are mainly attributed to the pathway of quenching of the excited species. After that, O and OH start to decay but show significant differences between unburnt and burnt zones, which are characterized by a single-exponential decay and a bi-exponential decay, respectively. In the unburnt zone, the OH decay is much slower than the O decay due to the diverse pathways for OH production. In the burnt zone, the bi-exponential decay of O and OH can essentially be regarded as a process in which the NH<sub>3</sub>/air reactive system reaches chemical equilibrium. At this stage, the impacts of the excited species from the plasma gradually diminish and combustion kinetics dominates alone.</p></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0010218024002384/pdfft?md5=f5e4006021249257e95e94129f145a8e&pid=1-s2.0-S0010218024002384-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141194246","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-29DOI: 10.1016/j.combustflame.2024.113524
C.E.A.G van Gool, T. Hazenberg, J.A. van Oijen, L.P.H. de Goey
Iron dust counter-flow flames have been studied with the low-Mach-number combustion approximation. The model considers full coupling between the two phases, including particle/droplet drag. The dispersed phase flow strain relations are derived in the Stokes regime (Reynolds number much smaller than unity). The importance of solving a particle flow strain model is demonstrated by comparing three different cases: a free unstrained flame, a counter-flow flame where slip effects are neglected and a counter-flow flame where slip effects are included. All three cases show preferential diffusion effects, due to the lack of diffusion of iron in the fuel mixture, e.g. 0. The preferential diffusion effect causes a peak in the fuel equivalence ratio in the preheat zone. On the burned side, the combined effect of strain and preferential diffusion shows a decrease in fuel equivalence ratio. Inertia effects, which are only at play in the counter-flow case with slip, counteract this effect and result in an increase of the fuel equivalence ratio on the burned side. A laminar flame speed analysis is performed and a recommendation is given on how to experimentally determine the flame speed in a counter-flow set-up.
Novelty & Significance
We introduce a novel model to include particle flow strain in a dispersed counter-flow set-up. For the first time, the impact of particle flow strain on the flame structure of iron dust is studied with a one-dimensional (1D) model. Two major effects that modify the flame structure and burning velocity are identified: preferential diffusion and inertia of the particles. Preferential diffusion effects are found to be always present in (iron) dust flames. Inertia effects play a role in the counter-flow case with slip. Due to the inertia of the particles, the particle flow strain is lower than the gas flow strain. As a consequence, higher particle concentrations are reached compared to the other cases. Furthermore, it is shown that each particle size experiences a different particle flow strain rate, which is important when doing experiments as it implies that the PSD at the flame front will be different than at the inlet.
{"title":"Numerical determination of iron dust laminar flame speeds with the counter-flow twin-flame technique","authors":"C.E.A.G van Gool, T. Hazenberg, J.A. van Oijen, L.P.H. de Goey","doi":"10.1016/j.combustflame.2024.113524","DOIUrl":"10.1016/j.combustflame.2024.113524","url":null,"abstract":"<div><p>Iron dust counter-flow flames have been studied with the low-Mach-number combustion approximation. The model considers full coupling between the two phases, including particle/droplet drag. The dispersed phase flow strain relations are derived in the Stokes regime (Reynolds number much smaller than unity). The importance of solving a particle flow strain model is demonstrated by comparing three different cases: a free unstrained flame, a counter-flow flame where slip effects are neglected and a counter-flow flame where slip effects are included. All three cases show preferential diffusion effects, due to the lack of diffusion of iron in the fuel mixture, e.g. <span><math><mrow><msub><mrow><mi>D</mi></mrow><mrow><mi>Fe</mi><mo>,</mo><mi>m</mi></mrow></msub><mo>=</mo></mrow></math></span> 0. The preferential diffusion effect causes a peak in the fuel equivalence ratio in the preheat zone. On the burned side, the combined effect of strain and preferential diffusion shows a decrease in fuel equivalence ratio. Inertia effects, which are only at play in the counter-flow case with slip, counteract this effect and result in an increase of the fuel equivalence ratio on the burned side. A laminar flame speed analysis is performed and a recommendation is given on how to experimentally determine the flame speed in a counter-flow set-up.</p><p><strong>Novelty & Significance</strong></p><p>We introduce a novel model to include particle flow strain in a dispersed counter-flow set-up. For the first time, the impact of particle flow strain on the flame structure of iron dust is studied with a one-dimensional (1D) model. Two major effects that modify the flame structure and burning velocity are identified: preferential diffusion and inertia of the particles. Preferential diffusion effects are found to be always present in (iron) dust flames. Inertia effects play a role in the counter-flow case with slip. Due to the inertia of the particles, the particle flow strain is lower than the gas flow strain. As a consequence, higher particle concentrations are reached compared to the other cases. Furthermore, it is shown that each particle size experiences a different particle flow strain rate, which is important when doing experiments as it implies that the PSD at the flame front will be different than at the inlet.</p></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0010218024002335/pdfft?md5=58e1345c91405220bb1beaa13456d8c6&pid=1-s2.0-S0010218024002335-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141194245","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-25DOI: 10.1016/j.combustflame.2024.113521
Mingxia Liu , Ruozhou Fang , Chih-Jen Sung , Khalid Aljohani , Aamir Farooq , Yousef Almarzooq , Olivier Mathieu , Eric L. Petersen , Philippe Dagaut , Jie Zhao , Zhiping Tao , Lijun Yang , Chong-Wen Zhou
{"title":"Corrigendum to “A comprehensive experimental and modeling study of n-propylcyclohexane oxidation” [Combust. Flame 238 (2022) 111944]","authors":"Mingxia Liu , Ruozhou Fang , Chih-Jen Sung , Khalid Aljohani , Aamir Farooq , Yousef Almarzooq , Olivier Mathieu , Eric L. Petersen , Philippe Dagaut , Jie Zhao , Zhiping Tao , Lijun Yang , Chong-Wen Zhou","doi":"10.1016/j.combustflame.2024.113521","DOIUrl":"https://doi.org/10.1016/j.combustflame.2024.113521","url":null,"abstract":"","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S001021802400230X/pdfft?md5=f5e402eb04b5a1ef9474e9e9b1d67513&pid=1-s2.0-S001021802400230X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141094919","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-25DOI: 10.1016/j.combustflame.2024.113520
Ashkan Beigzadeh , Mohammed Alabbad , Dapeng Liu , Khalid Aljohani , Khaiyom Hakimov , Touqeer Anwar Kashif , Kourosh Zanganeh , Eric Croiset , Aamir Farooq
{"title":"Corrigendum to “Reaction kinetics for high pressure hydrogen oxy-combustion in the presence of high levels of H2O and CO2” [Combust. Flame 247 (2023) 112498]","authors":"Ashkan Beigzadeh , Mohammed Alabbad , Dapeng Liu , Khalid Aljohani , Khaiyom Hakimov , Touqeer Anwar Kashif , Kourosh Zanganeh , Eric Croiset , Aamir Farooq","doi":"10.1016/j.combustflame.2024.113520","DOIUrl":"https://doi.org/10.1016/j.combustflame.2024.113520","url":null,"abstract":"","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0010218024002281/pdfft?md5=23a74dc8bf1a156b3cbb56f06eb9644a&pid=1-s2.0-S0010218024002281-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141095499","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-24DOI: 10.1016/j.combustflame.2024.113517
Jingru Zheng , Xiaolei Zhang , Suk Ho Chung , Longhua Hu
Ammonia is considered as a renewable fuel and expected to play an essential role in coping with the energy crisis and climate change. Because of low combustion rate and high NO emission of ammonia, many studies focused on the characteristics of ammonia/hydrocarbon mixture fuels. However, the flame height and radiation characteristics of jet flames of ammonia and hydrocarbon mixture fuels have not been systematically studied yet. In this work, hydrocarbon fuels of methane and ethylene are mixed with ammonia for the fuel mixing ratio in the range of 0 to 50 %. Results show that the flame height increases with heat release rate (HRR) but changes little with the concentration of ammonia. The previous physical models for turbulent jet flames based on an integral approach can basically predict the flame height for heat release rate larger than 2.7 kW and a semi empirical formula based on dimensional analysis is verified well in predicting the flame height with the flame Froude number for Frf > 0.05. For laminar flame heights, a model is proposed here considering the buoyancy effect which predicts well for CH4/NH3 flame with total flow rate smaller than 5 L/min. For thermal radiation characteristics, the radiation fraction decreases with the ammonia mixing ratio increases. A consistent transitional value in predicting the radiation fraction is observed, irrespective of fuel type, which is mainly due to the reduction of soot during the transition from laminar to turbulent flames. The influence of ammonia on the flame radiation fraction of CH4/NH3 flames normalized by that of pure hydrocarbon fuel () can be correlated by the mixing ratio. For C2H4/NH3 flames, the influence of ammonia on the dimensionless radiation fraction is the result of the coupling effect of mixing fraction and strain rate. A correlation is proposed considering the effects of ammonia addition on radiation fraction in relation to Reynolds number, which is shown to correlate well the experimental results.
Novelty and significance statement
As ammonia/hydrocarbon fuel mixtures can reduce the emission of carbon dioxide, it can play an essential role during the transition to a non-carbonization society. Considering a fundamental importance of jet flames and a fire hazard scenario in case of fuel leakage, the present study investigates the effect of ammonia addition on the flame height and flame radiation fraction for ammonia/hydrocarbon fuel mixtures. We test the physical model of Quintiere and a semi empirical formula of Delichatsios in predicting the turbulent flame height of ammonia/hydrocarbon mixture fuels. A normalized model is proposed to describe the effect of adding ammonia on radiation fraction in relation to the Reynolds
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{"title":"Corrigendum to “Ignition delay time and speciation of dibutyl ether at high pressures” [Combust. Flame 223 (2021) 98-109]","authors":"Khaiyom Hakimov , Farhan Arafin , Khalid Aljohani , Khalil Djebbi , Erik Ninnemann , Subith S. Vasu , Aamir Farooq","doi":"10.1016/j.combustflame.2024.113522","DOIUrl":"https://doi.org/10.1016/j.combustflame.2024.113522","url":null,"abstract":"","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0010218024002311/pdfft?md5=6ea773f8b0f725f1b2a3ff7a888f1ecc&pid=1-s2.0-S0010218024002311-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141095908","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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