Applications in Energy and Combustion Science最新文献

{"title":"Temperature evolution of laser-ignited micrometric iron particles: A comprehensive experimental data set and numerical assessment of laser heating impact","authors":"Leon C. Thijs ,&nbsp;Daoguan Ning ,&nbsp;Yuriy S. Shoshin ,&nbsp;Thijs Hazenberg ,&nbsp;XiaoCheng Mi ,&nbsp;Jeroen A. van Oijen ,&nbsp;Philip de Goey","doi":"10.1016/j.jaecs.2024.100284","DOIUrl":"10.1016/j.jaecs.2024.100284","url":null,"abstract":"<div><p>This study examines the effects of laser heating on the ignition and critical combustion characteristics, such as temperature and burn time, of individual iron particles. It provides time-dependent temperature profiles of laser-ignited particles across a broad spectrum of particle size distributions and oxygen concentrations obtained from experiments, which are a useful database for further development and validation of iron particle combustion models. The herein reported datasets significantly complement those existing in the literature. In the current study, the raw data are thoroughly re-evaluated using refined approaches. For the experimental canonical configuration of single iron particle combustion, an ignition system based on laser heating provides several advantages in overcoming temperature field uncertainties and facilitating controlled environments for optical diagnostics. Despite the inherent uncertainties in laser heating, associated with non-uniform intensity profiles and particle size variations, this study addresses the critical question of how these uncertainties affect <em>in situ</em> measurements of particle temperature and time to reach peak temperature. This study, conducted using a numerical model, reveals a dependence of the particle temperature after laser heating on particle size. However, this dependence does not significantly impact the key parameters of iron-particle combustion, such as the maximum temperature and burn time of the laser-ignited iron particle. The study also presents a comparison between the simulated particle temperature histories and those derived from two-color pyrometry measurements for a wide range of particle size distributions and oxygen concentrations. Notably, by implementing a laser-heating sub-model into an iron particle combustion model, assuming external-diffusion-limited oxidation only up to stoichiometric FeO, the temperature evolution up to the maximum temperature is reasonably captured for a wide range of particle sizes (20–<span><math><mrow><mn>53</mn><mspace></mspace><mi>μ</mi><mi>m</mi></mrow></math></span>) and oxygen volumetric fractions (14–21<!--> <!-->vol% O<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> mixed with N<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>). However, with increasing oxygen concentration, the external-diffusion limited model significantly overestimates the heating rate and subsequently the maximum particle temperature.</p></div>","PeriodicalId":100104,"journal":{"name":"Applications in Energy and Combustion Science","volume":"19 ","pages":"Article 100284"},"PeriodicalIF":5.0,"publicationDate":"2024-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666352X24000396/pdfft?md5=ca35ebf742a2a41053af38601ddba753&pid=1-s2.0-S2666352X24000396-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141984950","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Micron-sized aluminum particle combustion under elevated gas condition: Equivalence ratio effect","authors":"Pikai Zhang ,&nbsp;Chenyang Cao ,&nbsp;Huangwei Zhang","doi":"10.1016/j.jaecs.2024.100283","DOIUrl":"10.1016/j.jaecs.2024.100283","url":null,"abstract":"<div><p>Micron-sized aluminum (Al) particle combustion under elevated gas condition is critical for improving energetic material performance, impacting propulsion and explosives technology. This study utilizes Eulerian-Lagrangian method to investigate Al particle combustion dynamics, encompassing both heterogeneous reaction (HTR) and homogeneous reaction (HMR). It focuses on the critical role of the equivalence ratio in single Al particle combustion, highlighting the interplay between HTR and HMR, aiming to optimize energy release and emission control. Our study identifies four stages in the combustion of a single Al particle, where the highest heat release is attributed to HTR, succeeded by HMR, and the minimal from unburned Al vapor. We observe a decline in the total heat release rate with an increasing equivalence ratio, primarily due to the differential impacts of heterogeneous and homogeneous reactions. The thermal-runaway stage in HTR is governed by the particle temperature, while the subsequent decaying stage is influenced by either the diminishing effective Al droplet diameter or the availability of oxygen, contingent upon the fuel conditions. Utilizing Cantera software to analyze HMR allows us to elucidate the thermal effects of elementary reactions and the key reaction pathways. These findings underscore the complex interactions between Al particles and the surrounding gas, providing insights into optimizing the conditions for Al-containing reaction systems.</p></div>","PeriodicalId":100104,"journal":{"name":"Applications in Energy and Combustion Science","volume":"19 ","pages":"Article 100283"},"PeriodicalIF":5.0,"publicationDate":"2024-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666352X24000384/pdfft?md5=58dd33c76dfc420eedea1a9279f7666a&pid=1-s2.0-S2666352X24000384-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141952024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Scale effects on rotating detonation rocket engine operation","authors":"Tyler Mundt,&nbsp;Carl Knowlen,&nbsp;Mitsuru Kurosaka","doi":"10.1016/j.jaecs.2024.100282","DOIUrl":"10.1016/j.jaecs.2024.100282","url":null,"abstract":"<div><p>Rotating detonation rocket engines are propulsive devices employing detonation waves moving circumferentially around an annular channel that consume axially fed propellants. Theoretically, this provides benefits with respect to combustion pressure gain and thermodynamic efficiency when compared to deflagration-based combustors. To facilitate size scaling of these devices, the relationships between geometric parameters, performance, and wave dynamics have been investigated with gaseous methane-oxygen propellant. Empirical relations were derived between combustor geometry, fueling conditions, and engine operation, as well as correlation to thermodynamic parameters calculated with chemical kinetics codes. The radius of curvature effects were explored in annular combustors having outer diameters of 25 mm, 51 mm, and 76 mm with a fixed gap width of 5 mm. The injectors were scaled to have same oxidizer-to-fuel injector port area ratio, impingement distance, and injector-to-gap area ratio. Larger combustors had higher wave counts during operation at a given mass flux and equivalence ratio. Combustor axial pressures were found to be more dependent on propellant mass flux and equivalence ratio than geometry. Mass flux and the inner-to-outer radius ratio, the latter of which was related to other geometric ratios, dictated the operating mode transition thresholds and the number of resulting waves, respectively.</p></div>","PeriodicalId":100104,"journal":{"name":"Applications in Energy and Combustion Science","volume":"19 ","pages":"Article 100282"},"PeriodicalIF":5.0,"publicationDate":"2024-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666352X24000372/pdfft?md5=4e9f755def84db9f5c520eb97dc9624d&pid=1-s2.0-S2666352X24000372-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141838625","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"ChemPlasKin: A general-purpose program for unified gas and plasma kinetics simulations","authors":"Xiao Shao,&nbsp;Deanna A. Lacoste,&nbsp;Hong G. Im","doi":"10.1016/j.jaecs.2024.100280","DOIUrl":"10.1016/j.jaecs.2024.100280","url":null,"abstract":"<div><p>This work introduces ChemPlasKin, a freely accessible solver optimized for zero-dimensional (0D) simulations of chemical kinetics of neutral gas in non-equilibrium plasma environments. By integrating the electron Boltzmann equation solver, CppBOLOS, with the open-source combustion library, Cantera, at the source code level, ChemPlasKin computes time-resolved evolution of species concentration and gas temperature in a unified gas–plasma kinetics framework. The model allows high fidelity predictions of both chemical thermal effects and plasma-induced heating, including fast gas heating and slower vibrational–translational relaxation processes. Additionally, a new heat loss model is developed for nanosecond pulsed discharges, specifically within pin–pin electrode configurations. With its versatility, ChemPlasKin is well-suited for a wide range of applications, from plasma-assisted combustion (PAC) to fuel reforming. In this paper, the reliability, accuracy and efficiency of ChemPlasKin are validated through a number of test problems, demonstrating its utility in advancing gas–plasma kinetic studies.</p></div>","PeriodicalId":100104,"journal":{"name":"Applications in Energy and Combustion Science","volume":"19 ","pages":"Article 100280"},"PeriodicalIF":5.0,"publicationDate":"2024-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666352X24000359/pdfft?md5=7dfac2dbd589d8f72c87b54a95d8e550&pid=1-s2.0-S2666352X24000359-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141960543","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Towards detailed combustor wall kinetics: An experimental and kinetic modeling study of hydrogen oxidation on Inconel","authors":"Wenxian Tang ,&nbsp;Andre Nicolle ,&nbsp;Qi Wang ,&nbsp;Andres Cardenas-Alvarez ,&nbsp;Bambar Davaasuren ,&nbsp;S. Mani Sarathy","doi":"10.1016/j.jaecs.2024.100281","DOIUrl":"10.1016/j.jaecs.2024.100281","url":null,"abstract":"<div><p>Gas-phase hydrogen combustion is ubiquitous in industrial processes, and the associated surface kinetics on heat-resistant alloys plays a crucial role in designing efficient low-carbon technologies. We conducted new temperature programmed reduction experiments to determine the reducibility of materials following an oxidation cycle. These experiments were modeled using a thermoconsistent multi-site microkinetic model for H₂ heterogeneous oxidation on Inconels, which was validated against literature experiments. This competitive adsorption model considers iron bulk content, hydrogen spillover and subsurface oxygen migration on hydrogen surface oxidation kinetics. New X-ray diffraction experiments confirmed the postulated crystallographic structures in the Inconel samples, suggesting their presence on the surface scale. The phenomenological model was coupled with several state-of-the-art gas-phase oxidation mechanisms to assess gas/surface reactions interaction as a function of material and temperature. The results reveal a complex interaction in which surface removes H radicals from the gas-phase, while the Bradford (H₂+OH) reaction converts OH into H₂O, promoting water adsorption on Inconel. This interaction was found to give rise to gas-phase thermokinetic oscillations. The model predicts a non-monotonous effect of reactor area-to-volume ratio on reactivity and emphasizes the impact of Inconel composition on product selectivity. Overall, the multi-site model provides new insight into the contrasting reactivities among active sites, bridging the gap between material science and heterogeneous combustion modeling.</p></div>","PeriodicalId":100104,"journal":{"name":"Applications in Energy and Combustion Science","volume":"19 ","pages":"Article 100281"},"PeriodicalIF":5.0,"publicationDate":"2024-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666352X24000360/pdfft?md5=35b70ddcf6e65b82cafd9c5faa110511&pid=1-s2.0-S2666352X24000360-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141706802","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quasi-CJ rotating detonation with partially premixed methane-oxygen injection: Numerical simulation and experimental validation","authors":"Pierre Hellard ,&nbsp;Thomas Gaillard ,&nbsp;Dmitry Davidenko ,&nbsp;Patrick Berterretche ,&nbsp;Ratiba Zitoun ,&nbsp;Pierre Vidal","doi":"10.1016/j.jaecs.2024.100278","DOIUrl":"10.1016/j.jaecs.2024.100278","url":null,"abstract":"<div><p>The efficiency gain of rotating detonation depends on several loss factors related to the chamber geometry, the injection principle, the propellants and their mass flow rates, and the equivalence ratio. Numerical simulation can help quantify these losses, and this work presents a Large Eddy Simulation (LES) of rotating detonation in an annular chamber and its validation against experiments. The simulation captured the mixing processes, the overall dynamics of the detonation, the deflagration, and the burnt gas expansion. The injection device was numerically designed to ensure partial premixing of the propellants before injection into the chamber. The chamber had a length of 110 mm, an outer diameter of 80 mm, and a radial width of 10 mm. The mixture consisted of gaseous CH<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span> and O<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> with an equivalence ratio of 1.2 and a mass flow rate of 160 g/s. Combustion kinetics was modeled using a skeletal mechanism with 62 reactions and 16 species. The boundary conditions were adiabatic slip walls. The results reproduce well the detonation velocity (within 1% deviation) and the pressure variation behind the wave. The simulated OH* chemiluminescence compares well with experimental high-speed imaging of the outlet and side of the chamber. The simulation results indicate that 65% of the propellant mass is well mixed in front of the wave whereas 15% of the mixture is burned by deflagration. They show that CH<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span> and O<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> do not axially stratify because they have similar injection dynamics between periodic perturbations induced by the rotating detonation. Good propellant mixing and low deflagration losses explain the high experimental detonation velocity, about 90% of <span><math><msub><mrow><mi>D</mi></mrow><mrow><mtext>CJ</mtext></mrow></msub></math></span>, and a high combustion efficiency of 98%. These agreements between the computational and experimental results indicate that the simulation is capable of capturing the physical scales relevant to RDC operation and producing reliable results for RDC design.</p></div>","PeriodicalId":100104,"journal":{"name":"Applications in Energy and Combustion Science","volume":"19 ","pages":"Article 100278"},"PeriodicalIF":5.0,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666352X24000335/pdfft?md5=07e504d9addddbec666917b4a2591212&pid=1-s2.0-S2666352X24000335-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141637943","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"MILD combustion characteristics of a premixed CH4/air jet flame in hot coflow from a bluff-body burner","authors":"Xiangtao Liu ,&nbsp;Guochang Wang ,&nbsp;Jicang Si ,&nbsp;Pengfei Li ,&nbsp;Mengwei Wu ,&nbsp;Jianchun Mi","doi":"10.1016/j.jaecs.2024.100279","DOIUrl":"10.1016/j.jaecs.2024.100279","url":null,"abstract":"<div><p>This numerical study is designated to comparatively investigate premixed CH₄/air jet flames from bluff-body (BB) and non-BB (NBB) burners in the coflow of hot exhaust gas. Specifically, traditional combustion (TC) from BB burner (BB-TC), MILD combustion (MC) from BB burner (BB-MC), and NBB burner (NBB-MC) under varying coflow temperatures (<em>T</em>_C) and oxygen concentrations (<em>Y</em>_{O2, C}) are considered. The flow field, combustion reactions, temperature rise, heat release, along with reaction zone, and pollutant emissions are thoroughly investigated. The findings underscore the feasibility of achieving MILD combustion using the BB burner. Remarkably, the small recirculation zone generated by the BB enhances entrainment and mixing, leading to superior combustion stability and reduced CO emission in the BB-MC case compared to the conventional NBB-MC case. Moreover, the BB-MC case exhibits a higher peak temperature, reaction rate, and heat release rate than the NBB-MC case, albeit with slightly higher NO emission. When compared to the BB-TC case, NO emission from both the BB-MC and NBB-MC cases are significantly lower, particularly under relatively low <em>T</em>_C and <em>Y</em>_{O2, C} conditions.</p></div>","PeriodicalId":100104,"journal":{"name":"Applications in Energy and Combustion Science","volume":"19 ","pages":"Article 100279"},"PeriodicalIF":5.0,"publicationDate":"2024-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666352X24000347/pdfft?md5=ee9364dae841baf08081ea86d7cf4555&pid=1-s2.0-S2666352X24000347-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141704127","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dynamics of regime transition of autoignitive jet flames from conventional to MILD combustion","authors":"Aravind Ramachandran ,&nbsp;Abinash Sahoo ,&nbsp;Venkateswaran Narayanaswamy ,&nbsp;Kevin M. Lyons","doi":"10.1016/j.jaecs.2024.100277","DOIUrl":"https://doi.org/10.1016/j.jaecs.2024.100277","url":null,"abstract":"<div><p>Turbulent combustion of jet flames in a hot diluted coflow of combustion products has been studied across a range of jet Reynolds numbers for propane, ethylene, and an ethylene-propane blend as fuels. The study revealed a transition from conventional autoignitive combustion to a regime of Moderate or Intense Low-oxygen Dilution (MILD) combustion, which is characterized by a nearly invisible flame. The flames studied are luminous at low jet velocities and become MILD at higher jet velocities. Planar Laser-Induced Fluorescence (PLIF) of formaldehyde (<span><math><mrow><mi>C</mi><msub><mi>H</mi><mn>2</mn></msub><mi>O</mi></mrow></math></span>), a key intermediate species in hydrocarbon combustion, is combined with CH*-chemiluminescence imaging and Rayleigh scattering to investigate the phenomena. The transition to MILD combustion is found to accompany a broadening of the formaldehyde region, indicating a broader low-temperature reaction zone. As the transition is approached, the appearance of holes in the chemiluminescent front is also observed. Correspondence between the location and structure of these holes with regions of formaldehyde in the flame are illustrated. These regions are proposed to be signatures that precede the transition to a fully MILD flame. In other words, the transition to MILD combustion begins at a local level and the MILD region spreads to engulf the entire combusting mixture. Scalar gradients were imaged to further unravel the local turbulence/chemistry interactions that yield the MILD inception. The measured scalar gradients were found to be commensurate with scalar gradients obtained from chemical kinetic simulations at the stoichiometric mixture fractions, while being an order of magnitude larger at other locations; this suggests that the inception of MILD combustion occurs near the stoichiometric region.</p></div>","PeriodicalId":100104,"journal":{"name":"Applications in Energy and Combustion Science","volume":"19 ","pages":"Article 100277"},"PeriodicalIF":5.0,"publicationDate":"2024-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666352X24000323/pdfft?md5=d63cc13d678b65899f6e076d6de26b37&pid=1-s2.0-S2666352X24000323-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141539573","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Flamelet LES of pulverized coal combustion and NO formation characteristics in a supercritical CO2 boiler","authors":"Xinzhou Tang ,&nbsp;Chunguang Zhao ,&nbsp;Jiangkuan Xing ,&nbsp;Ruipeng Cai ,&nbsp;Kun Luo ,&nbsp;Jianren Fan ,&nbsp;Mingyan Gu","doi":"10.1016/j.jaecs.2024.100274","DOIUrl":"https://doi.org/10.1016/j.jaecs.2024.100274","url":null,"abstract":"<div><p>In the present study, LESs of a modeled typical combustion zone of a 1000 MW S-CO₂ coal-fired boiler using a hybrid flamelet/progress variable model are conducted for the first time. In the hybrid model, both the fuel-N from volatiles and char are considered, and two progress variables are used for major species and NO, respectively. The combustion and NO formation characteristics at different regions are qualitatively and quantitatively investigated. The results indicate that the mixture of primary air and secondary air, the high-temperature wall as well as the adjacent flame can promote the pulverized coal combustion (PCC) and NO formation. In addition, the effects of wall temperature and flue gas recirculation on PCC and NO formation are investigated. The results show that compared with the supercritical H₂O boiler, a slight rise of 2.08% and 3.05% for temperature and NO production can be observed in the supercritical CO₂ boiler due to a higher wall temperature; flue gas recirculation with a recirculation rate of 27% can effectively reduce the production of NO by 57.6% in the supercritical CO₂ boiler.</p></div>","PeriodicalId":100104,"journal":{"name":"Applications in Energy and Combustion Science","volume":"19 ","pages":"Article 100274"},"PeriodicalIF":0.0,"publicationDate":"2024-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666352X24000293/pdfft?md5=28efbb189b70b3500ebd054966244a2b&pid=1-s2.0-S2666352X24000293-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141328317","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"MILD combustion stabilization issues through the analysis of hysteresis behaviors: The case of new energy carriers","authors":"P. Sabia ,&nbsp;M.V. Manna ,&nbsp;F. Mauss ,&nbsp;R. Ragucci","doi":"10.1016/j.jaecs.2024.100276","DOIUrl":"https://doi.org/10.1016/j.jaecs.2024.100276","url":null,"abstract":"<div><p>MILD combustion processes are renewed to reveal a strong resilience to extinction phenomena and/or instabilities, whereas the oxidation process is stabilized trough ignition phenomena. Under MILD conditions, igni-diffusive and/or perfectly mixed kernels, forming during the mixing process between hot products and fresh reactants, are so much diluted and pre-heated to escape classical feed-back flammable flames stabilization mechanisms, while ignition and extinction events merge in a unique condition through “anhysteretic” behaviors. So far, considering methane as reference fuel, it has been largely demonstrated the mentioned “anhysteretic” condition is very conservative and defines a sub-domain of MILD combustion processes, following Cavaliere and de Joannon's definition. Furthermore, the coincidence of ignition and extinction phenomena can occur also preserving hysteresis phenomena. In turns, this condition strongly enlarges the stabilization domain of MILD combustion processes, starting from the upper branch of the hysteresis behaviors to the real extinction, with characteristic unstable loci to consider as further/last opportunity to promote stable operative conditions through the formation of local thermo-kinetic conditions in the combustion chamber during hot products/fresh reactants mixing process (injection configuration/burner design), or by forced ignition events. The hysteresis behaviors of renewable/alternative fuels, relevant within the decarbonization policies of several energy sectors, are thoroughly discussed under MILD conditions through numerical studies in model reactors in order to shed light on common and/or different features, and outline practical rules towards the definition of stable MILD combustion domains. Results show that, as MILD combustion is a chemical kinetics-driven processes, stability issues have to be discussed in relation to fuel nature, albeit with common behavior can be derived. The coincidence between extinction/ignition phenomena is reached for extremely diluted conditions, already ascribable to MILD combustion conditions, thus defining a small sub-domain of the process. This condition can be reached through “hysteretic” or “anhysteretic” behaviors.</p></div>","PeriodicalId":100104,"journal":{"name":"Applications in Energy and Combustion Science","volume":"19 ","pages":"Article 100276"},"PeriodicalIF":0.0,"publicationDate":"2024-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666352X24000311/pdfft?md5=b3f17574829838af82d217d154d272c1&pid=1-s2.0-S2666352X24000311-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141250922","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}