Applications in Energy and Combustion Science最新文献

{"title":"Chemiluminescence- and machine learning-based monitoring of premixed ammonia-methane-air flames","authors":"Thibault F. Guiberti ,&nbsp;Nader N. Shohdy ,&nbsp;Santiago Cardona ,&nbsp;Xuren Zhu ,&nbsp;Laurent Selle ,&nbsp;Corentin J. Lapeyre","doi":"10.1016/j.jaecs.2023.100212","DOIUrl":"https://doi.org/10.1016/j.jaecs.2023.100212","url":null,"abstract":"<div><p>This work presents the development and validation of an algorithm capable of predicting the equivalence ratio and the ammonia fraction of premixed ammonia-methane-air flames using only measured OH*, NH*, CN*, and CH* chemiluminescence intensities as input. This machine learning algorithm relies on Gaussian process regression (GPR). It was trained and validated with data previously recorded in laminar flames, and it was then tested with new data recorded in more practical, turbulent swirl flames. The algorithm performs well for laminar and turbulent flames for wide ranges of equivalence ratio (0.80 ≤ <em>ϕ</em> ≤ 1.20) and ammonia fraction (0 ≤ X_NH3 ≤ 0.60). For turbulent swirl flames, the prediction errors in the equivalence ratio and on the ammonia fraction are smaller than 0.05, except for a very small subset of operating conditions where the error is up to 0.10. Additional tests were performed by adding NO* and CO₂* to the list of inputs, but this did not improve the predictions. The GPR algorithm was then benchmarked against linear and polynomial regressions and a more conventional way of inferring flame properties from chemiluminescence measurements, namely the ratio-based method. This method relies only on CN*/NO* and NH*/CH* ratios to predict the equivalence ratio and the ammonia fraction. Its prediction errors were often larger than 0.15, which is significantly worse than that of the GPR algorithm. Consequently, this work constitutes a solid basis for the future development of non-intrusive sensors to monitor practical ammonia-methane-air flames.</p></div>","PeriodicalId":100104,"journal":{"name":"Applications in Energy and Combustion Science","volume":"16 ","pages":"Article 100212"},"PeriodicalIF":0.0,"publicationDate":"2023-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49744358","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optical study of active narrow throat pre-chamber assisted internal combustion engine at lean limit","authors":"Priybrat Sharma ,&nbsp;Qinglong Tang ,&nbsp;Ramgopal Sampath ,&nbsp;Ponnya Hlaing ,&nbsp;Manuel Echeverri Marquez ,&nbsp;Emre Cenker ,&nbsp;Gaetano Magnotti","doi":"10.1016/j.jaecs.2023.100209","DOIUrl":"https://doi.org/10.1016/j.jaecs.2023.100209","url":null,"abstract":"<div><p>The pre-chamber assisted ignition offers several much-needed upgrades to gas engines, ranging from improved combustion efficiency and stability to extended lean limits. The concept has received intermittent attention from researchers over the past century, and the concept's fundamental understanding remains segmented. This study investigates pre-chamber assisted combustion (PCC) in a heavy-duty gas engine fueled by methane at the lean limits. The engine is operated at two lean limits at intake pressures of 1.2 and 1.4 bar. At lower intake pressure, global excess air ratio (λ_global) is 2.4, while at higher intake pressure λ_global is 2.6. The comparison of two lean limits through experimental data and GT-Power 1D model reveals the underlying ignition and combustion. Using a combination of acetone PLIF (N-PLIF) and OH* chemiluminescence imaging allows visualization of both the reacting and non-reacting part of the pre-chamber jet. The results suggest that pressure differential across the pre-chamber and main chamber controls the reacting jet growth speed. The combustion chamber boundaries affect the main combustion through the wall jet part of the impinging pre-chamber jets as higher OH* concentrations are observable at stagnation points of the jet. In addition, the study reports the appearance of post-combustion jets and dispersed OH* pockets as the combustion dwindles. The narrow throat pre-chamber shows a spectral pressure signature reminiscent of the Helmholtz oscillator, and circumferential resonant modes dominate the main chamber combustion. Although the PCC offers great ignitibility, the main chamber mixture cannot sustain prolonged combustion at a lean limit lambda value.</p></div>","PeriodicalId":100104,"journal":{"name":"Applications in Energy and Combustion Science","volume":"16 ","pages":"Article 100209"},"PeriodicalIF":0.0,"publicationDate":"2023-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49743967","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Uncertainty quantification of a deep learning fuel property prediction model","authors":"Kiran K. Yalamanchi ,&nbsp;Sahil Kommalapati ,&nbsp;Pinaki Pal ,&nbsp;Nursulu Kuzhagaliyeva ,&nbsp;Abdullah S AlRamadan ,&nbsp;Balaji Mohan ,&nbsp;Yuanjiang Pei ,&nbsp;S. Mani Sarathy ,&nbsp;Emre Cenker ,&nbsp;Jihad Badra","doi":"10.1016/j.jaecs.2023.100211","DOIUrl":"https://doi.org/10.1016/j.jaecs.2023.100211","url":null,"abstract":"<div><p>Deep learning models are being widely used in the field of combustion. Given the black-box nature of typical neural network based models, uncertainty quantification (UQ) is critical to ensure the reliability of predictions as well as the training datasets, and for a principled quantification of noise and its various sources. Deep learning surrogate models for predicting properties of chemical compounds and mixtures have been recently shown to be promising for enabling data-driven fuel design and optimization, with the ultimate goal of improving efficiency and lowering emissions from combustion engines. In this study, UQ is performed for a multi-task deep learning model that simultaneously predicts the research octane number (RON), Motor Octane Number (MON), and Yield Sooting Index (YSI) of pure components and multicomponent blends. The deep learning model is comprised of three smaller networks: Extractor 1, Extractor 2, and Predictor, and a mixing operator. The molecular fingerprints of individual components are encoded via Extractor 1 and Extractor 2, the mixing operator generates fingerprints for mixtures/blends based on linear mixing operation, and the predictor maps the fingerprint to the target properties. Two different classes of UQ methods, Monte Carlo ensemble methods and Bayesian neural networks (BNNs), are employed for quantifying the epistemic uncertainty. Combinations of Bernoulli and Gaussian distributions with DropConnect and DropOut techniques are explored as ensemble methods. All the DropConnect, DropOut and Bayesian layers are applied to the predictor network. Aleatoric uncertainty is modeled by assuming that each data point has an independent uncertainty associated with it. The results of the UQ study are further analyzed to compare the performance of BNN and ensemble methods. Although this study is confined to UQ of fuel property prediction, the methodologies are applicable to other deep learning frameworks that are being widely used in the combustion community.</p></div>","PeriodicalId":100104,"journal":{"name":"Applications in Energy and Combustion Science","volume":"16 ","pages":"Article 100211"},"PeriodicalIF":0.0,"publicationDate":"2023-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49757664","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Turbulence effects on the formation and growth of nano-particles in three-dimensional premixed and non-premixed flames","authors":"Luis Cifuentes ,&nbsp;Irenäus Wlokas ,&nbsp;Patrick Wollny ,&nbsp;Andreas Kempf","doi":"10.1016/j.jaecs.2023.100210","DOIUrl":"https://doi.org/10.1016/j.jaecs.2023.100210","url":null,"abstract":"<div><p>This study examines the impact of turbulence on particle-forming flames via three-dimensional direct numerical simulations. The simulations employ the finite rate chemistry approach to simulate both premixed and non-premixed methane-air turbulent planar jet flames. These flames are doped with titanium tetraisopropoxide (TTIP) to form titanium dioxide TiO₂ nanoparticles. The sectional model is employed to solve the population balance equation governing particle dynamics. Through these simulations, a number of the Batchelor scales pertaining to the smaller nanoparticle structures are effectively captured. The analysis conducted on these simulations is to identify and quantify the respective influences of diffusion, coagulation, and inception on variations in particle concentration across different regions within the flame. Several regions of the computational domain with different turbulence intensities are analyzed. Results show that the physical mechanisms that contribute to particle growth are not negligible on the particle concentrations. The impact of normal <span><math><msub><mrow><mi>a</mi></mrow><mrow><mi>N</mi></mrow></msub></math></span> and tangential <span><math><msub><mrow><mi>a</mi></mrow><mrow><mi>T</mi></mrow></msub></math></span> strain rates, which govern the thickness of particle-loaded zones affected by turbulence effects, is also evaluated. Conditional mean values of the strain rates upon the particle number concentration fields and the PDFs of <span><math><msub><mrow><mi>a</mi></mrow><mrow><mi>N</mi></mrow></msub></math></span> and <span><math><msub><mrow><mi>a</mi></mrow><mrow><mi>T</mi></mrow></msub></math></span> confirm that on the iso-surfaces of the particle fields the compressive and stretching effects are predominant. The aforementioned information is used to gain a deeper understanding of the influence of turbulence on premixed and non-premixed particle-forming flames, which will help us to develop transferable models for the simulation of nanoparticle synthesis.</p></div>","PeriodicalId":100104,"journal":{"name":"Applications in Energy and Combustion Science","volume":"16 ","pages":"Article 100210"},"PeriodicalIF":0.0,"publicationDate":"2023-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49744462","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental observation of the TJI-initiated HPDI gas combustion: Vertically crossed flame jet and methane jet","authors":"Lijia Zhong ,&nbsp;Wanhui Zhao ,&nbsp;Haiqiao Wei ,&nbsp;Lei Zhou","doi":"10.1016/j.jaecs.2023.100207","DOIUrl":"https://doi.org/10.1016/j.jaecs.2023.100207","url":null,"abstract":"<div><p>In the field of natural gas marine engines, the high-pressure direct injection (HPDI) technology is widely used to achieve emission reduction while maintaining equivalent thermal efficiency and power output compared to diesel engines. In these engines, the in-cylinder combustion is primarily initiated by the diesel spray flame near the top dead center (TDC). In the present work, pre-chamber turbulent jet ignition (TJI) is employed to substitute diesel injection to initiate the combustion of HPDI methane jets. The optical experiments of ignition and flame development in the TJI-HPDI system with various injector configurations and injection/ignition control parameters are conducted in a constant-volume combustion chamber (CVCC). It is revealed that with the increase of injection-ignition delay(<em>ti</em>), three ignition modes are observed sequentially: methane jet suppresses ignition, methane jet first suppresses ignition then promotes flame propagation, and direct ignition and promoted flame propagation. The effect of various injection-ignition delays and injection pulse width were explored. The injection-ignition delay significantly influences the combustion characteristics such as heat release rate, while the injection pulse width influences the duration of the lifted jet flame. The flame lift-off length first decreases and then increases due to variations in thermodynamic conditions and oxygen concentration. With a larger-nozzle injector, the critical injection-ignition delay to initiate the main chamber combustion is significantly reduced. Moreover, the use of different nozzle diameters leads to varying levels of turbulent intensity in the methane jet, which in turn affects the combustion behavior.</p></div>","PeriodicalId":100104,"journal":{"name":"Applications in Energy and Combustion Science","volume":"16 ","pages":"Article 100207"},"PeriodicalIF":0.0,"publicationDate":"2023-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49744084","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Catalyst-heating operation in compression-ignition engines: A comprehensive understanding using large eddy simulations","authors":"Dario Lopez-Pintor ,&nbsp;Stephen Busch ,&nbsp;Angela Wu ,&nbsp;Tuan Nguyen ,&nbsp;Joonsik Hwang ,&nbsp;Seokwon Cho","doi":"10.1016/j.jaecs.2023.100203","DOIUrl":"https://doi.org/10.1016/j.jaecs.2023.100203","url":null,"abstract":"<div><p>Catalyst-heating operation in compression-ignition engines is critical to ensure rapid light-off of exhaust catalysts during cold-start. This is typically achieved by using late post injections for increased exhaust enthalpy, where retardability is constrained mainly by emissions due to inactivity of the oxidation catalyst at these conditions. Comprehensive understanding of formation mechanism of pollutant emissions is needed to optimize engine performance and minimize tailpipe harmful emissions. In this study, a computational fluid dynamics model of a medium-duty compression-ignition engine is developed and validated against with catalyst-heating operation experimental data using large eddy simulations. The engine is fueled with a full boiling-range diesel fuel and uses an optimized five-injections strategy that consists of two pilots, one main, and two post injections. Results show that, significant amounts of unburned hydrocarbons (UHCs) and oxygenated UHCs (OUHC) are formed by the pilot injections, which may persist until exhaust valve opening. UHCs accumulate mainly in the outer-upper part of the cylinder guided by the piston lip, in the inner-bowl due to the bowl geometry, near the injector nozzle by the fuel from the end-phase of injection, and in the space between spray plumes transported by the swirl motion. The main injection exhibits a short ignition delay and rapidly consumes most of UHC and OUHC, except for the central part of the chamber near the injector nozzle. The 1^st post injection counteracts the expansion effect on temperature, plays a key role in increasing the exhaust enthalpy and reducing the harmful emissions by promoting combustion associated with the 2^nd post injection. The fuel delivered by the 2^nd post injection penetrates through the flame of the 1^st post injection, creating cool flame clouds beyond the flame that eventually transition to a diffusion flame. Finally, a unique phenomenological model is proposed to better visualize the interactions of post injections.</p></div>","PeriodicalId":100104,"journal":{"name":"Applications in Energy and Combustion Science","volume":"16 ","pages":"Article 100203"},"PeriodicalIF":0.0,"publicationDate":"2023-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49744472","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of a single nanosecond pulsed discharge on a flat methane–air flame","authors":"Yupan Bao ,&nbsp;Chengdong Kong ,&nbsp;Jonas Ravelid ,&nbsp;Jinguo Sun ,&nbsp;Sebastian Nilsson ,&nbsp;Elias Kristensson ,&nbsp;Andreas Ehn","doi":"10.1016/j.jaecs.2023.100198","DOIUrl":"https://doi.org/10.1016/j.jaecs.2023.100198","url":null,"abstract":"<div><p>Successful implementation of plasma-assisted combustion in applied thermal processes heavily relies on how the plasma can be formed as it interacts with the reactive flow and what the effects are of such a plasma on the combustion process. The current study is an experimental investigation of a plasma-assisted lifted flat methane–air flame by a nanosecond pulsed discharge at atmospheric pressure. The nanosecond pulsed discharge, with a pulse duration of 4 ns and an amplitude of 30 kV to 50 kV, is used to stimulate the flame with a repetition rate of 1 Hz. The flame/plasma interactions are investigated with electrical and optical/laser diagnostics to study plasma-formation and its effect on the temperatures and formaldehyde formation. The flame speed seems to be accelerated for tens of milliseconds after the plasma stimulation, without noticeable gas temperature increase at the flame front and in the post-flame region. Formaldehyde is formed in the unburnt region while there is a slight increase in formaldehyde signal in the preheat zone. These results show that a volumetric effect of plasma-assisted combustion can be achieved with a short nanosecond plasma from a single excitation.</p></div>","PeriodicalId":100104,"journal":{"name":"Applications in Energy and Combustion Science","volume":"16 ","pages":"Article 100198"},"PeriodicalIF":0.0,"publicationDate":"2023-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49758003","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fuel temperature and injection pressure influence on the cold start GDI sprays","authors":"Kyungwon Lee ,&nbsp;Dario Lopez Pintor ,&nbsp;Dimitris Assanis ,&nbsp;Seokwon Cho ,&nbsp;Joonsik Hwang","doi":"10.1016/j.jaecs.2023.100206","DOIUrl":"https://doi.org/10.1016/j.jaecs.2023.100206","url":null,"abstract":"<div><p>Cold start in gasoline direct injection engines (GDI) is a critical issue that significantly impacts fuel consumption and emissions. Therefore, it is essential to investigate and improve the spray and air-fuel mixing processes during cold starts. This study employed a complimentary set of optical diagnostic techniques, including line-of-sight(extinction, Schlieren, and long-distance microscopy) and 3D computed tomography (CT), to characterize and understand the cold-start spray dynamics under various fuel temperature and injection pressure conditions. The experiments were conducted in a constant volume spray vessel and the fuel temperature was varied using a coolant circulator, with temperatures reaching as low as -7 °C to simulate cold-start conditions. The cold fuel exhibited longer liquid/vapor penetration lengths compared to hot fuel under low injection pressure conditions. This deterioration in spray characteristics was attributed to the attenuated fuel evaporation and reduced entrainment of ambient air. The 3D spray visualization obtained through the CT algorithm, particularly the cut plane images, revealed that plumes with low fuel temperatures had narrower individual plume widths, resulting in minimized plume-to-plume interaction. Microscopic imaging further confirmed this observation which showed separate plumes in the near-nozzle region for cold fuel conditions. Meanwhile, hot fuel under high injection pressure conditions exhibited complete plume collapsing, leading to a significant amount of liquid fuel remaining in the spray core. The liquid penetration reached 70 mm during the injection period, potentially can cause wall wetting on the piston top or cylinder wall. Based on the experimental findings, this study suggests the application of multiple injections with a moderate level of injection pressure for optimized engine performance and reduced emissions during cold starts.</p></div>","PeriodicalId":100104,"journal":{"name":"Applications in Energy and Combustion Science","volume":"16 ","pages":"Article 100206"},"PeriodicalIF":0.0,"publicationDate":"2023-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49744558","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental characterization of ammonia, methane, and gasoline fuel mixtures in small scale spark ignited engines","authors":"Kaushik Nonavinakere Vinod,&nbsp;Matt Gore,&nbsp;Hanzhang Liu,&nbsp;Tiegang Fang","doi":"10.1016/j.jaecs.2023.100205","DOIUrl":"https://doi.org/10.1016/j.jaecs.2023.100205","url":null,"abstract":"<div><p>In this study, gaseous anhydrous ammonia is blended with fuels like gasoline and methane and tested in an instrumented, low-technology single cylinder carbureted engine. In-cylinder pressure and emissions are monitored with the various mixtures and their performance is then compared with pure gasoline. With the addition of ammonia, the stability of combustion inside the combustion chamber was affected. But with the addition of a combustion modifier, the overall variability was reduced. At higher substitutions of ammonia, Initial results show an increase in indicated thermal efficiency of the engine. There is also a substantial decrease in the heat release rate (HRR) of the engine when substituting gasoline with ammonia. With the addition of methane, the change in the fuel reactivity helped improve HRR. Increasing ammonia substitution also resulted in an increase in indicated efficiency when compared to pure gasoline by approximately 12% with 50% substitution of ammonia in gasoline. Adding ammonia to the fuel mixtures also showed an initial reduction in unburnt hydrocarbon emission, followed by a sudden increase with further increasing concentration, suggesting incomplete combustion of the fuel mixture. The addition of methane with gasoline also showed a reduction in overall NO_x emissions. Furthermore, methane was also tested as the main fuel with ammonia substitution of up to 50%. This ammonia and methane blend also showed comparable results to the gasoline, ammonia, and methane blends tested. From the emissions data, the catalyzing effects of ammonia were also seen with some cases showing varying trends with increasing ammonia substitution. Results from this study can be used to design small-scale engine based power generation systems that need very little modifications to accept ammonia based mixed fuels. Furthermore, this study lays the groundwork for using fuels blends with methane sourced using carbon neutral technologies and ammonia to power engine based systems.</p></div>","PeriodicalId":100104,"journal":{"name":"Applications in Energy and Combustion Science","volume":"16 ","pages":"Article 100205"},"PeriodicalIF":0.0,"publicationDate":"2023-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49744574","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The reactor-based perspective on finite-rate chemistry in turbulent reacting flows: A review from traditional to low-emission combustion","authors":"Arthur Péquin ,&nbsp;Michael J. Evans ,&nbsp;Alfonso Chinnici ,&nbsp;Paul R. Medwell ,&nbsp;Alessandro Parente","doi":"10.1016/j.jaecs.2023.100201","DOIUrl":"https://doi.org/10.1016/j.jaecs.2023.100201","url":null,"abstract":"<div><p>In flames, turbulence can either limit or enhance combustion efficiency by means of strain and mixing. The interactions between turbulent motions and chemistry are crucial to the behaviour of combustion processes. In particular, it is essential to correctly capture non-equilibrium phenomena such as localised ignition and extinction to faithfully predict pollutant formation. Reactor-based combustion models — such as the Eddy Dissipation Concept (EDC) or Partially Stirred Reactor (PaSR) — may account for turbulence-chemistry interactions at an affordable computational cost by calculating combustion rates relying upon canonical reactors of small fluid size and timescale. The models may include multiscale mixing, detailed chemical kinetic schemes and high-fidelity multispecies diffusion treatments. Although originally derived for conventional, highly turbulent combustion, numerous recent efforts have sought to generalise beyond simple empirical correlations using more sophisticated relationships. More recent models incorporate the estimation of scales based on local variables such as turbulent Reynolds and Damköhler numbers, phenomenological descriptions of turbulence based on fractal theory or specific events such as extinction. These modifications significantly broaden the effective range of operating conditions and combustion regimes these models can be applied to, as in the particular case of Moderate or Intense Low-oxygen Dilution (MILD) combustion. MILD combustion is renown for its ability to deliver appealing features such as abated pollutant emissions, elevated thermal efficiency and fuel flexibility. This review describes the development and current state-of-the-art in finite-rate, reactor-based combustion approaches. Recently investigated model improvements and adaptations will be discussed, with specific focus on the MILD combustion regime. Finally, to bridge the gap between laboratory-scale canonical burners and industrial combustion systems, the current directions and the future outlook for development are discussed.</p></div>","PeriodicalId":100104,"journal":{"name":"Applications in Energy and Combustion Science","volume":"16 ","pages":"Article 100201"},"PeriodicalIF":0.0,"publicationDate":"2023-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49764026","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}