Applications in Energy and Combustion Science最新文献

Towards detailed combustion characteristics and linear stability analysis of premixed ammonia‒hydrogen‒air mixtures

IF 5 Q2 ENERGY & FUELS

Applications in Energy and Combustion Science

Pub Date : 2025-02-18 DOI: 10.1016/j.jaecs.2025.100325

Jun Cheng, Bo Zhang

In this study, premixed ammonia‒hydrogen‒air mixtures at different pressures (50∼300 kPa), equivalence ratios (0.7∼1.5), and hydrogen concentrations (9∼50.00 %) were centrally ignited in a closed vessel, and the propagation of a spherical flame was recorded via a high-speed schlieren system. To accurately measure the laminar burning velocity, an AI model (RTMDet model) was trained on the schlieren images obtained in the experiments to mark the flame profile and calculate the flame area. The corresponding laminar combustion parameters were measured. Additionally, linear stability theory was applied to evaluate the critical conditions for the onset of flame instability. The results indicate that the hydrodynamic instability exhibits greater sensitivity to the initial pressure and equivalent ratio, whereas the molecular diffusion is remarkably sensitive to the hydrogen concentration in lean conditions. For the lean mixture, flame destabilization is enhanced by the thermal‒diffusion instability and curvature effect, whereas for the rich mixture, both the hydrodynamic instability and thermal‒diffusion instability is diminished, and flame stabilization is determined by the stretching effect. The critical Peclet number monotonically decreases as the equivalence ratio decreases and the hydrogen concentration increases. Hydrodynamic instability consistently promotes flame destabilization, whereas thermal-diffusion instability does not invariably contribute positively; for the lean mixtures, both the strain rate and curvature make the flame unstable, whereas they make the flame stable for the rich mixtures. The hydrogen concentration has a relatively limited effect on the strain rate and curvature. Additionally, the critical Karlovitz number indicates that flames in rich conditions are less susceptible to disturbances and instability. This study enhances the understanding of intrinsic instability mechanisms during flame propagation in ammonia‒hydrogen blended fuels, improves insights into their combustion characteristics, and provides a reference for optimizing combustion performance.

{"title":"Towards detailed combustion characteristics and linear stability analysis of premixed ammonia‒hydrogen‒air mixtures","authors":"Jun Cheng, Bo Zhang","doi":"10.1016/j.jaecs.2025.100325","DOIUrl":"10.1016/j.jaecs.2025.100325","url":null,"abstract":"<div><div>In this study, premixed ammonia‒hydrogen‒air mixtures at different pressures (50∼300 kPa), equivalence ratios (0.7∼1.5), and hydrogen concentrations (9∼50.00 %) were centrally ignited in a closed vessel, and the propagation of a spherical flame was recorded via a high-speed schlieren system. To accurately measure the laminar burning velocity, an AI model (RTMDet model) was trained on the schlieren images obtained in the experiments to mark the flame profile and calculate the flame area. The corresponding laminar combustion parameters were measured. Additionally, linear stability theory was applied to evaluate the critical conditions for the onset of flame instability. The results indicate that the hydrodynamic instability exhibits greater sensitivity to the initial pressure and equivalent ratio, whereas the molecular diffusion is remarkably sensitive to the hydrogen concentration in lean conditions. For the lean mixture, flame destabilization is enhanced by the thermal‒diffusion instability and curvature effect, whereas for the rich mixture, both the hydrodynamic instability and thermal‒diffusion instability is diminished, and flame stabilization is determined by the stretching effect. The critical Peclet number monotonically decreases as the equivalence ratio decreases and the hydrogen concentration increases. Hydrodynamic instability consistently promotes flame destabilization, whereas thermal-diffusion instability does not invariably contribute positively; for the lean mixtures, both the strain rate and curvature make the flame unstable, whereas they make the flame stable for the rich mixtures. The hydrogen concentration has a relatively limited effect on the strain rate and curvature. Additionally, the critical Karlovitz number indicates that flames in rich conditions are less susceptible to disturbances and instability. This study enhances the understanding of intrinsic instability mechanisms during flame propagation in ammonia‒hydrogen blended fuels, improves insights into their combustion characteristics, and provides a reference for optimizing combustion performance.</div></div>","PeriodicalId":100104,"journal":{"name":"Applications in Energy and Combustion Science","volume":"21 ","pages":"Article 100325"},"PeriodicalIF":5.0,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143465507","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}

引用次数: 0

bio-FLASHCHAIN® theory for rapid devolatilization of biomass. 10. Validations for agricultural residues

IF 5 Q2 ENERGY & FUELS

Applications in Energy and Combustion Science

Pub Date : 2025-02-12 DOI: 10.1016/j.jaecs.2025.100323

Stephen Niksa

This study further validates a reaction mechanism called bio-FLASHCHAIN® to simulate the rapid primary devolatilization of any agricultural residue (AgRes) at any operating conditions. The evaluations cover 42 residues with alkali and alkaline earth metal (AAEM) levels to 2.8 dry wt. % at temperatures from 200 to 1050 °C; heating rates from 1 to 5000 °C/s; contact times to 1800 s; and pressures from vacuum to atmospheric. Collectively, the test data cover the yields and elemental compositions of oils and char and the yields of CO, CO₂, H₂O, and H₂. Bio-FC™ accurately simulates complete product distributions over this domain and correctly depicts how variations in heating rate, temperature, contact time, pressure, and AAEM loading shift these distributions. Proximate and ultimate analyses, the percentages of cellulose, hemicellulose, and lignin, and AAEM loadings are required input.

This study demonstrates, for the first time, accurate extrapolations across nearly the entire range of heating rates in the target commercial applications, based on two independent kinetic aspects. First, the placement of a devolatilization history in temperature is determined by the absolute rates of depolymerization and charring for each major component in the biomass; and, second, differences in ultimate yields for multiple heating rates scale on the ratios of the rates of depolymerization and charring. The interpretations for two disparate heating rates each for four AgRes gave activation energies for both depolymerization and monomer decomposition that varied by 50 – 60 kJ/mol in each of the major components, in stark contrast with the uniform energies used to previously interpret wood devolatilization.

{"title":"bio-FLASHCHAIN® theory for rapid devolatilization of biomass. 10. Validations for agricultural residues","authors":"Stephen Niksa","doi":"10.1016/j.jaecs.2025.100323","DOIUrl":"10.1016/j.jaecs.2025.100323","url":null,"abstract":"<div><div>This study further validates a reaction mechanism called <em>bio</em>-FLASHCHAIN® to simulate the rapid primary devolatilization of any agricultural residue (AgRes) at any operating conditions. The evaluations cover 42 residues with alkali and alkaline earth metal (AAEM) levels to 2.8 dry wt. % at temperatures from 200 to 1050 °C; heating rates from 1 to 5000 °C/s; contact times to 1800 s; and pressures from vacuum to atmospheric. Collectively, the test data cover the yields and elemental compositions of oils and char and the yields of CO, CO<sub>2</sub>, H<sub>2</sub>O, and H<sub>2</sub>. <em>Bio</em>-FC™ accurately simulates complete product distributions over this domain and correctly depicts how variations in heating rate, temperature, contact time, pressure, and AAEM loading shift these distributions. Proximate and ultimate analyses, the percentages of cellulose, hemicellulose, and lignin, and AAEM loadings are required input.</div><div>This study demonstrates, for the first time, accurate extrapolations across nearly the entire range of heating rates in the target commercial applications, based on two independent kinetic aspects. First, the placement of a devolatilization history in temperature is determined by the absolute rates of depolymerization and charring for each major component in the biomass; and, second, differences in ultimate yields for multiple heating rates scale on the ratios of the rates of depolymerization and charring. The interpretations for two disparate heating rates each for four AgRes gave activation energies for both depolymerization and monomer decomposition that varied by 50 – 60 kJ/mol in each of the major components, in stark contrast with the uniform energies used to previously interpret wood devolatilization.</div></div>","PeriodicalId":100104,"journal":{"name":"Applications in Energy and Combustion Science","volume":"21 ","pages":"Article 100323"},"PeriodicalIF":5.0,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143420334","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}

引用次数: 0

Influence of surface cooling on the deposition behavior of combusting Iron particles

IF 5 Q2 ENERGY & FUELS

Applications in Energy and Combustion Science

Pub Date : 2025-02-06 DOI: 10.1016/j.jaecs.2025.100322

Steven Floor , Jesse Hameete , XiaoCheng Mi

This work explores the impact of actively cooling the wall surface on the deposition behavior of combusting iron particles. Experiments were conducted with a Jet-in-Hot-Coflow (JHC) burner to analyze how a reduced wall temperature and wall material properties influence particle deposition behaviors. Multiple wall materials were utilized for the experiments. The deposition was quantified by measuring the deposited volume of samples using optical profilometry. The experimental results showed a clear reduction in deposition when active wall cooling was applied across all metallic wall materials under varying experiment durations. The material properties of the metal walls do impact deposition when cooling is applied, although the differences are small. Particle agglomeration is observed on cooled metal plates, suggesting a tendency for particles to adhere to other particles rather than the wall surface. Clear signs of wall melting were found on deposition plates that were not cooled. This observation suggests that cooling the wall material reduces wall melting, thereby decreasing deposition. Further testing with concrete plates uncovered that wall surface roughness can also influence deposition.

{"title":"Influence of surface cooling on the deposition behavior of combusting Iron particles","authors":"Steven Floor , Jesse Hameete , XiaoCheng Mi","doi":"10.1016/j.jaecs.2025.100322","DOIUrl":"10.1016/j.jaecs.2025.100322","url":null,"abstract":"<div><div>This work explores the impact of actively cooling the wall surface on the deposition behavior of combusting iron particles. Experiments were conducted with a Jet-in-Hot-Coflow (JHC) burner to analyze how a reduced wall temperature and wall material properties influence particle deposition behaviors. Multiple wall materials were utilized for the experiments. The deposition was quantified by measuring the deposited volume of samples using optical profilometry. The experimental results showed a clear reduction in deposition when active wall cooling was applied across all metallic wall materials under varying experiment durations. The material properties of the metal walls do impact deposition when cooling is applied, although the differences are small. Particle agglomeration is observed on cooled metal plates, suggesting a tendency for particles to adhere to other particles rather than the wall surface. Clear signs of wall melting were found on deposition plates that were not cooled. This observation suggests that cooling the wall material reduces wall melting, thereby decreasing deposition. Further testing with concrete plates uncovered that wall surface roughness can also influence deposition.</div></div>","PeriodicalId":100104,"journal":{"name":"Applications in Energy and Combustion Science","volume":"21 ","pages":"Article 100322"},"PeriodicalIF":5.0,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143349306","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}

引用次数: 0

Observing simultaneous low temperature heat release and deflagration in a spark ignition engine using formaldehyde planar laser induced fluorescence

IF 5 Q2 ENERGY & FUELS

Applications in Energy and Combustion Science

Pub Date : 2025-01-22 DOI: 10.1016/j.jaecs.2025.100321

Samuel P. White, Christopher Willman, Felix C.P. Leach

Low temperature heat release (LTHR) and its underlying chemistry is of particular interest for its potential to mitigate knock in spark ignition (SI) engines and enable advanced combustion strategies that rely on end gas autoignition. It has been proposed that, in SI engines, LTHR can occur volumetrically in the end gas, after ignition, whilst deflagration occurs elsewhere in the cylinder, however, current pressure-based heat release metering techniques are unable to distinguish such LTHR from high temperature heat release (HTHR) due to the overlapping pressure rise characteristics. Planar laser-induced fluorescence (PLIF) of formaldehyde, a known product of LTHR which is consumed during HTHR, offers an opportunity to detect end gas LTHR simultaneously with deflagration but is challenging to implement, as end gas is often located closer to cylinder walls and away from typical optically accessible locations. An optically accessible SI engine was used to show formaldehyde PLIF signal intensity under motored conditions is well correlated to cumulative LTHR intensity, using a recent method to isolate LTHR in SI engine conditions. An alternative ignition method using four side-mounted spark plugs was implemented to generate end gas close to the cylinder axis. This enabled measurement of LTHR within the end gas during the deflagration process of a SI engine, demonstrating the utility of formaldehyde PLIF to optically measure LTHR under conditions where pressure-based diagnostics cannot isolate the contribution of LTHR.

{"title":"Observing simultaneous low temperature heat release and deflagration in a spark ignition engine using formaldehyde planar laser induced fluorescence","authors":"Samuel P. White, Christopher Willman, Felix C.P. Leach","doi":"10.1016/j.jaecs.2025.100321","DOIUrl":"10.1016/j.jaecs.2025.100321","url":null,"abstract":"<div><div>Low temperature heat release (LTHR) and its underlying chemistry is of particular interest for its potential to mitigate knock in spark ignition (SI) engines and enable advanced combustion strategies that rely on end gas autoignition. It has been proposed that, in SI engines, LTHR can occur volumetrically in the end gas, after ignition, whilst deflagration occurs elsewhere in the cylinder, however, current pressure-based heat release metering techniques are unable to distinguish such LTHR from high temperature heat release (HTHR) due to the overlapping pressure rise characteristics. Planar laser-induced fluorescence (PLIF) of formaldehyde, a known product of LTHR which is consumed during HTHR, offers an opportunity to detect end gas LTHR simultaneously with deflagration but is challenging to implement, as end gas is often located closer to cylinder walls and away from typical optically accessible locations. An optically accessible SI engine was used to show formaldehyde PLIF signal intensity under motored conditions is well correlated to cumulative LTHR intensity, using a recent method to isolate LTHR in SI engine conditions. An alternative ignition method using four side-mounted spark plugs was implemented to generate end gas close to the cylinder axis. This enabled measurement of LTHR within the end gas during the deflagration process of a SI engine, demonstrating the utility of formaldehyde PLIF to optically measure LTHR under conditions where pressure-based diagnostics cannot isolate the contribution of LTHR.</div></div>","PeriodicalId":100104,"journal":{"name":"Applications in Energy and Combustion Science","volume":"21 ","pages":"Article 100321"},"PeriodicalIF":5.0,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143155119","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}

引用次数: 0

Comprehensive reevaluation of acetaldehyde chemistry - part I: Assessment of important kinetic parameters and the underlying uncertainties

IF 5 Q2 ENERGY & FUELS

Applications in Energy and Combustion Science

Pub Date : 2025-01-11 DOI: 10.1016/j.jaecs.2025.100320

Xinrui Ren , Hongqing Wu , Ruoyue Tang , Yanqing Cui , Mingrui Wang , Song Cheng

Understanding the combustion chemistry of acetaldehyde is crucial to developing robust and accurate combustion chemistry models for practical fuels, especially for biofuels. This study aims to re-evaluate the important rate and thermodynamic parameters for acetaldehyde combustion chemistry and determine the physical uncertainties of these parameters. The rate parameters of 79 key reactions are reevaluated using > 100,000 direct experiments and quantum chemistry computations from > 900 studies, and the thermochemistry (Δh_f(298 K), s⁰(298 K) and c_p) of 24 key species are reevaluated based on the ATCT database, the NIST Chemistry WebBook, the TMTD database, and 35 published chemistry models. The updated parameters are incorporated into a recent acetaldehyde chemistry model, which is further assessed against available fundamental experiments measurements (10 RCM-IDT, 123 ST-IDT, 633 JSR-species concentrations, and 102 flow reactor-species concentrations) and existing chemistry models, with clearly better performance obtained in the high-temperature regime. Sensitivity and flux analyses further highlight the insufficiencies of previous models in representing the key pathways, particularly the branching ratios of acetaldehyde- and formaldehyde-consuming pathways. Meanwhile, temperature-dependent and temperature-independent uncertainties are statistically evaluated for kinetic and thermochemical parameters, respectively, where the large differences between the updated and the original model parameters reveal the necessity of reassessment of kinetic and thermochemical parameters completely based on direct experiments and theoretical calculations for rate and thermodynamic parameters. The application of the determined uncertainty domains of the key kinetic and thermodynamic parameters is further demonstrated through a case study, with the modelling uncertainty and its reliability highlighted. With the configured uncertainty domain of the updated acetaldehyde chemistry model, further uncertainty quantification and optimization can be conducted to improve the model performance, which is currently under progress in the authors’ group.

{"title":"Comprehensive reevaluation of acetaldehyde chemistry - part I: Assessment of important kinetic parameters and the underlying uncertainties","authors":"Xinrui Ren , Hongqing Wu , Ruoyue Tang , Yanqing Cui , Mingrui Wang , Song Cheng","doi":"10.1016/j.jaecs.2025.100320","DOIUrl":"10.1016/j.jaecs.2025.100320","url":null,"abstract":"<div><div>Understanding the combustion chemistry of acetaldehyde is crucial to developing robust and accurate combustion chemistry models for practical fuels, especially for biofuels. This study aims to re-evaluate the important rate and thermodynamic parameters for acetaldehyde combustion chemistry and determine the physical uncertainties of these parameters. The rate parameters of 79 key reactions are reevaluated using > 100,000 direct experiments and quantum chemistry computations from > 900 studies, and the thermochemistry (<em>Δh<sub>f</sub></em>(298 K), <em>s<sup>0</sup></em>(298 K) and <em>c<sub>p</sub></em>) of 24 key species are reevaluated based on the ATCT database, the NIST Chemistry WebBook, the TMTD database, and 35 published chemistry models. The updated parameters are incorporated into a recent acetaldehyde chemistry model, which is further assessed against available fundamental experiments measurements (10 RCM-IDT, 123 ST-IDT, 633 JSR-species concentrations, and 102 flow reactor-species concentrations) and existing chemistry models, with clearly better performance obtained in the high-temperature regime. Sensitivity and flux analyses further highlight the insufficiencies of previous models in representing the key pathways, particularly the branching ratios of acetaldehyde- and formaldehyde-consuming pathways. Meanwhile, temperature-dependent and temperature-independent uncertainties are statistically evaluated for kinetic and thermochemical parameters, respectively, where the large differences between the updated and the original model parameters reveal the necessity of reassessment of kinetic and thermochemical parameters completely based on direct experiments and theoretical calculations for rate and thermodynamic parameters. The application of the determined uncertainty domains of the key kinetic and thermodynamic parameters is further demonstrated through a case study, with the modelling uncertainty and its reliability highlighted. With the configured uncertainty domain of the updated acetaldehyde chemistry model, further uncertainty quantification and optimization can be conducted to improve the model performance, which is currently under progress in the authors’ group.</div></div>","PeriodicalId":100104,"journal":{"name":"Applications in Energy and Combustion Science","volume":"21 ","pages":"Article 100320"},"PeriodicalIF":5.0,"publicationDate":"2025-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143155118","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}

引用次数: 0

Simultaneous 10 kHz PIV/OH-PLIF/chemiluminescence and conjoint data analysis approach for thermoacoustic oscillation near lean blowout

IF 5 Q2 ENERGY & FUELS

Applications in Energy and Combustion Science

Pub Date : 2025-01-08 DOI: 10.1016/j.jaecs.2025.100319

Zhen Cao , Wenbei Liu , Xin Yu , Bin Hu , Jiangbo Peng , PengHua Qiu , Chaobo Yang

Simultaneous multi-parameter experimental data characterizing the flow-combustion interaction process are of great significance for understanding the flame instability mechanism in combustion systems. In this study, we present simultaneous high-speed particle image velocimetry (PIV), OH planar laser-induced fluorescence (OH-PLIF), chemiluminescence, and acoustic pressure measurements of lean blowout (LBO) flames contained within a dual swirl-stabilized combustor to analyze the thermal-fluid-acoustic multi-field coupling process. The instability transition behavior and generation process of thermoacoustic oscillations near-LBO are experimentally investigated and analyzed. We identify two unstable swirling flame conditions, the transition and near-LBO, based on the dynamic behaviors of the dual flames, with significant thermoacoustic instability characteristics observed near 570 Hz through microphone measurements. Additionally, we investigate the spatiotemporal evolution of heat release and flow structure oscillations using spectral proper orthogonal decomposition (SPOD). As the flame approaches LBO, the axial vibration mode becomes predominant in both heat release and flow oscillation processes, with flow instability primarily concentrated in the flame arm zone. A joint analysis of SPOD data from PIV and chemiluminescence reveals an in-phase coupling between the flow field and heat release fluctuations, providing direct evidence of the triggering mechanism for thermoacoustic oscillations near LBO. Furthermore, the time-frequency analysis results illustrate the chronological sequence and causality between acoustic oscillations and heat release fluctuations during the LBO process.

{"title":"Simultaneous 10 kHz PIV/OH-PLIF/chemiluminescence and conjoint data analysis approach for thermoacoustic oscillation near lean blowout","authors":"Zhen Cao , Wenbei Liu , Xin Yu , Bin Hu , Jiangbo Peng , PengHua Qiu , Chaobo Yang","doi":"10.1016/j.jaecs.2025.100319","DOIUrl":"10.1016/j.jaecs.2025.100319","url":null,"abstract":"<div><div>Simultaneous multi-parameter experimental data characterizing the flow-combustion interaction process are of great significance for understanding the flame instability mechanism in combustion systems. In this study, we present simultaneous high-speed particle image velocimetry (PIV), OH planar laser-induced fluorescence (OH-PLIF), chemiluminescence, and acoustic pressure measurements of lean blowout (LBO) flames contained within a dual swirl-stabilized combustor to analyze the thermal-fluid-acoustic multi-field coupling process. The instability transition behavior and generation process of thermoacoustic oscillations near-LBO are experimentally investigated and analyzed. We identify two unstable swirling flame conditions, the transition and near-LBO, based on the dynamic behaviors of the dual flames, with significant thermoacoustic instability characteristics observed near 570 Hz through microphone measurements. Additionally, we investigate the spatiotemporal evolution of heat release and flow structure oscillations using spectral proper orthogonal decomposition (SPOD). As the flame approaches LBO, the axial vibration mode becomes predominant in both heat release and flow oscillation processes, with flow instability primarily concentrated in the flame arm zone. A joint analysis of SPOD data from PIV and chemiluminescence reveals an in-phase coupling between the flow field and heat release fluctuations, providing direct evidence of the triggering mechanism for thermoacoustic oscillations near LBO. Furthermore, the time-frequency analysis results illustrate the chronological sequence and causality between acoustic oscillations and heat release fluctuations during the LBO process.</div></div>","PeriodicalId":100104,"journal":{"name":"Applications in Energy and Combustion Science","volume":"21 ","pages":"Article 100319"},"PeriodicalIF":5.0,"publicationDate":"2025-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143155113","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}

引用次数: 0

Integrating green hydrogen into building-distributed multi-energy systems with water recirculation

IF 5 Q2 ENERGY & FUELS

Applications in Energy and Combustion Science

Pub Date : 2024-12-23 DOI: 10.1016/j.jaecs.2024.100318

Hanhui Lei , Joseph Thomas , Oliver Curnick , K.V. Shivaprasad , Sumit Roy , Lu Xing

This study proposes integrating a building-distributed multi-energy system (BDMES) with green hydrogen to decarbonise electricity generation for buildings. By producing and consuming green hydrogen locally at the building site, using a water electrolyser and proton exchange membrane fuel cell (PEMFC), the reliance on costly, energy and carbon-intensive hydrogen transportation is eliminated. This integration presents an opportunity for energy autonomy, achieved by locally green hydrogen production, storage, and usage. More importantly, the proposed system enables water recirculation between the electrolyser and PEMFC, an effective option worldwide to conserve water resources, and reduce environmental impact. Models are developed to investigate the interaction mechanisms among the photovoltaic (PV) module, water electrolyser, fuel cell, and cooling system. Case study results for a residential building in Aberdeen, UK are presented and discussed, maximum 75 solar panels can be installed on the 150m² roof area. Since less solar energy can be harvested in this area, in the peak hour of one summer day, 11 solar panels are required to meet 100 % daily maximum building energy demand and ensure 100 % water recirculation. In one winter-day, total 75 solar panels can only meet 26 % of total building energy demand.

{"title":"Integrating green hydrogen into building-distributed multi-energy systems with water recirculation","authors":"Hanhui Lei , Joseph Thomas , Oliver Curnick , K.V. Shivaprasad , Sumit Roy , Lu Xing","doi":"10.1016/j.jaecs.2024.100318","DOIUrl":"10.1016/j.jaecs.2024.100318","url":null,"abstract":"<div><div>This study proposes integrating a building-distributed multi-energy system (BDMES) with green hydrogen to decarbonise electricity generation for buildings. By producing and consuming green hydrogen locally at the building site, using a water electrolyser and proton exchange membrane fuel cell (PEMFC), the reliance on costly, energy and carbon-intensive hydrogen transportation is eliminated. This integration presents an opportunity for energy autonomy, achieved by locally green hydrogen production, storage, and usage. More importantly, the proposed system enables water recirculation between the electrolyser and PEMFC, an effective option worldwide to conserve water resources, and reduce environmental impact. Models are developed to investigate the interaction mechanisms among the photovoltaic (PV) module, water electrolyser, fuel cell, and cooling system. Case study results for a residential building in Aberdeen, UK are presented and discussed, maximum 75 solar panels can be installed on the 150m<sup>2</sup> roof area. Since less solar energy can be harvested in this area, in the peak hour of one summer day, 11 solar panels are required to meet 100 % daily maximum building energy demand and ensure 100 % water recirculation. In one winter-day, total 75 solar panels can only meet 26 % of total building energy demand.</div></div>","PeriodicalId":100104,"journal":{"name":"Applications in Energy and Combustion Science","volume":"21 ","pages":"Article 100318"},"PeriodicalIF":5.0,"publicationDate":"2024-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143155112","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}

引用次数: 0

High-resolution numerical simulation of rotating detonation waves with parallel adaptive mesh refinement

IF 5 Q2 ENERGY & FUELS

Applications in Energy and Combustion Science

Pub Date : 2024-12-20 DOI: 10.1016/j.jaecs.2024.100316

Han Peng , Ralf Deiterding

Simulations of rotating detonation engines are still dominated by solvers on uniform or statically refined meshes. Here, simulations of premixed rotating detonation waves are conducted using the block-structured adaptive mesh refinement (SAMR) technique. The studied configurations include both a two-dimensional unrolled model with a discretely injected hydrogen-air mixture and a three-dimensional annular model with non-premixed and partially premixed hydrogen-air mixtures. The computations employ a generic solver within the parallel Cartesian adaptive mesh refinement framework AMROC, which has been extended to accommodate curvilinear meshes. A second-order accurate finite volume method for the Navier–Stokes equations is utilized, along with grid-aligned Riemann solvers for thermally perfect gas mixtures. Detailed, multi-step chemical kinetic mechanisms are employed and incorporated with a splitting approach. A study into mesh dependency is undertaken, providing an assessment of the influence of local mesh refinement and adaptation criteria on the simulation results. The analysis reveals the formation of a multi-wave structure and transient heat release patterns, indicating the presence of an irregular cellular structure with enhanced local heat release as the detonation propagates through the injection jets. The ability to resolve sub-scale phenomena down to the cellular structures, intrinsic to detonation propagation, demonstrates the benefit of the SAMR approach. Further simulations are conducted to investigate the effects of partial premixing on rotating detonation. Additionally, a workload distribution analysis demonstrates how the on-the-fly partition strategy in AMROC alleviates computational imbalances. Parallel scaling tests exhibit linear acceleration in solving rotating detonation engine problems, highlighting the efficiency of the parallel adaptive mesh refinement technique in capturing the primary features of these simulations.

{"title":"High-resolution numerical simulation of rotating detonation waves with parallel adaptive mesh refinement","authors":"Han Peng , Ralf Deiterding","doi":"10.1016/j.jaecs.2024.100316","DOIUrl":"10.1016/j.jaecs.2024.100316","url":null,"abstract":"<div><div>Simulations of rotating detonation engines are still dominated by solvers on uniform or statically refined meshes. Here, simulations of premixed rotating detonation waves are conducted using the block-structured adaptive mesh refinement (SAMR) technique. The studied configurations include both a two-dimensional unrolled model with a discretely injected hydrogen-air mixture and a three-dimensional annular model with non-premixed and partially premixed hydrogen-air mixtures. The computations employ a generic solver within the parallel Cartesian adaptive mesh refinement framework AMROC, which has been extended to accommodate curvilinear meshes. A second-order accurate finite volume method for the Navier–Stokes equations is utilized, along with grid-aligned Riemann solvers for thermally perfect gas mixtures. Detailed, multi-step chemical kinetic mechanisms are employed and incorporated with a splitting approach. A study into mesh dependency is undertaken, providing an assessment of the influence of local mesh refinement and adaptation criteria on the simulation results. The analysis reveals the formation of a multi-wave structure and transient heat release patterns, indicating the presence of an irregular cellular structure with enhanced local heat release as the detonation propagates through the injection jets. The ability to resolve sub-scale phenomena down to the cellular structures, intrinsic to detonation propagation, demonstrates the benefit of the SAMR approach. Further simulations are conducted to investigate the effects of partial premixing on rotating detonation. Additionally, a workload distribution analysis demonstrates how the on-the-fly partition strategy in AMROC alleviates computational imbalances. Parallel scaling tests exhibit linear acceleration in solving rotating detonation engine problems, highlighting the efficiency of the parallel adaptive mesh refinement technique in capturing the primary features of these simulations.</div></div>","PeriodicalId":100104,"journal":{"name":"Applications in Energy and Combustion Science","volume":"21 ","pages":"Article 100316"},"PeriodicalIF":5.0,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143155117","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}

引用次数: 0

A spark energy deposition model in mixture fraction space for simulations of turbulent non-premixed flame ignition

IF 5 Q2 ENERGY & FUELS

Applications in Energy and Combustion Science

Pub Date : 2024-12-19 DOI: 10.1016/j.jaecs.2024.100317

Hazem S.A.M. Awad, Savvas Gkantonas, Epaminondas Mastorakos

Predicting the ignition probability remains important for designing reliable combustors. A spark ignition model in mixture fraction space is proposed and used in a Large Eddy Simulation (LES)-Conditional Moment Closure (CMC) simulation of initiation of a n-heptane spray swirl flame. The model is based on including source terms for the enthalpy and species that mimic the effect of plasma kinetics on the gaseous thermochemical state, in contrast to previous approaches that included only a heat source to the energy equation or a burning distribution in mixture fraction space as the initial condition. The model is evaluated based on its prediction of the ignition probability against experimental data. In laminar non-premixed counterflow flames, failed ignition case with low energy deposition have been found to successfully ignite when portion of the deposited energy has been assigned for the oxygen dissociation. In the turbulent spray swirl flame, the results reveal a tendency towards a successful ignition when the spark is subjected to a higher probability of finding stochiometric mixture fraction values, lower axial velocity and higher probability of finding negative axial velocities (pointing towards the bluff-body). The terms budget of the CMC equation is investigated for the successful and failed ignition events. The sum of convection and dilatation remains the dominant term to suppress the spark for the investigated realisations, and a tendency towards a failed ignition is observed when the spark energy assumes comparable magnitudes compared to the sum of convection and dilatation. In the vicinity of the spark, convection and turbulent diffusion remain of equal importance, with the latter dominating at later sparking time instants. The present approach quantitatively captures the ignition probability spatial distributions compared to the experiment. The proposed spark ignition model can improve the spark representation in CMC-based simulations, thereby allowing more reliable simulations in realistic combustors.

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引用次数: 0

Computational modeling of dynamic injector response in a Rotating Detonation Engine (RDE)

IF 5 Q2 ENERGY & FUELS

Applications in Energy and Combustion Science

Pub Date : 2024-12-04 DOI: 10.1016/j.jaecs.2024.100313

Piyush Raj, Ashwin Kumar, Joseph Meadows

Rotating Detonation Engines (RDEs) are a form of pressure gain combustion (PGC), offering a promising approach to increase the thermodynamic efficiency of a gas turbine combustor by utilizing a detonation-driven combustion process. In most RDEs, fuel and oxidizer are discretely injected from separate plenums. The discrete fuel/oxidizer injection locations are influenced by the local chamber conditions, leading to mixture inhomogeneity in the combustor. The objective of this study is to develop a dynamic injector response model capable of simulating injector behavior without the need to mesh/resolve the individual injectors. A series of 3D non-reacting computational fluid dynamics (CFD) simulations is used to generate empirical correlations for mass flux and mixture inhomogeneity. These correlations are then implemented as spatially/temporally varying inlet boundary conditions in 2D reacting RDE simulations. The obtained results are compared against experimental data and perfectly premixed simulations for two different RDE geometries, each at two separate operating conditions, focusing on wave speed and static pressure measurements for validation. The injector response model predicted wave speed, which is approximately within 10% of the experimental value. The time-averaged static pressure data determined from the injector response model also lies within the uncertainty limits of experimental measurements, suggesting good agreement between them. The injector response model also provides a computationally cost effective way to incorporate dynamic transient injector response in RDE simulation without meshing/resolving the individual injectors. Additionally, the influence of injector response on wave dynamics, wave structures, and detonation efficiency is investigated.

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引用次数: 0