Combustion and Flame最新文献

{"title":"Experimental and kinetic model studies of 2,3-dimethylhexane pyrolysis at atmospheric pressure","authors":"Jinzeng Pan ,&nbsp;Jinyu Tan ,&nbsp;Shiling Wei ,&nbsp;Shuyao Chen ,&nbsp;Haikun Lang ,&nbsp;Fangping Bin ,&nbsp;Zhandong Wang ,&nbsp;Lixia Wei","doi":"10.1016/j.combustflame.2024.113781","DOIUrl":"10.1016/j.combustflame.2024.113781","url":null,"abstract":"<div><div>Isomers of alkanes have a significant effect on their combustion performance. In order to better understand the effect of the number of methyl side chains on fuel performance, the pyrolysis experiments of 2,3-dimethylhexane (C₈H₁₈–23) were carried out by using a jet-stirred reactor and the synchrotron vacuum ultraviolet photoionization mass spectrometry at 770 - 1130 K and at atmospheric pressure. Key pyrolysis products, such as acetylene, ethylene, propene, 1,3-butadiene, 2-butene, 1-pentene, 2-methyl-2-butene, 2-methyl-2-hexene, 3-methyl-2-hexene, as well as benzene, styrene and naphthalene, etc., were identified and measured. A detailed kinetic model of C₈H₁₈–23 pyrolysis, including 1756 species and 6023 reactions, was constructed and validated against the experimental results in the present work. Rate of production and sensitivity analysis of C₈H₁₈–23 showed that the major consumption pathways are H-abstractions and unimolecular dissociation reactions, with the highest contributions from those at/between C(2) and C(3) atoms. Theoretical comparison of the pyrolysis of the three isomers of C₈H₁₈ hydrocarbon, i.e., C₈H₁₈–23, 2-methylheptane and <em>n-</em>octane, shows that with increasing of the number of methyl side chains, C₈H₁₈ will be more reactive in pyrolysis and be more effective in producing soot precursors.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"270 ","pages":"Article 113781"},"PeriodicalIF":5.8,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142445586","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unraveling combustion chemistry of dimethyldiethoxysilane. II. A comprehensive study on the laminar flame propagation of ethoxysilane flame synthesis precursors","authors":"Qilong Fang ,&nbsp;Jun Fang ,&nbsp;Yi Zhang ,&nbsp;Tianyou Lian ,&nbsp;Wei Li ,&nbsp;Lili Ye ,&nbsp;Yuyang Li","doi":"10.1016/j.combustflame.2024.113795","DOIUrl":"10.1016/j.combustflame.2024.113795","url":null,"abstract":"<div><div>The ethoxysilane family is a popular precursor family for SiO₂ nanoparticle flame synthesis, understanding their combustion characteristics and reaction mechanisms are essential to control the synthesis performance. However, there is a scarcity of fundamental combustion studies on ethoxysilane precursors, particularly regarding fuel decomposition and oxidation under flame circumstances. This work, as the second part of a serial work on the combustion of dimethyldiethoxysilane (DMDEOS) which is a representative ethoxysilane precursor, reports an experimental, theoretical, and kinetic modeling investigation on its laminar flames. Laminar burning velocities of the DMDEOS/air mixtures are obtained using the spherically propagating flame method at the initial pressure of 1 atm and initial temperature of 423 K, and equivalence ratios from 0.7 to 1.5. The H-abstraction reactions of DMDEOS by H, CH₃, and OH, followed by the subsequent isomerization and β-scission reactions of fuel radicals, are theoretically investigated using <em>ab initio</em> quantum chemical calculations and rate constant calculations. A kinetic model of DMDEOS combustion incorporated with the present theoretical results is developed and validated against the new data. The rate of production analysis and sensitivity analysis indicate that the CH₃SiOOH plays an important role in the laminar flame propagation of DMDEOS/air mixtures, and the relevant reactions exhibit significant sensitivity for the laminar flame propagation of DMDEOS. Additionally, the consumption of CH₃SiOOH is the main source of key species that are essential for molecular growth. The modified fictitious diluent gas method is adopted to provide insights into the fuel molecular structure effects from the comparison with diethoxymethane (DEM), which has the same molecular skeleton length as DMDEOS. The thermal effect plays a dominantly positive role in the slower laminar flame propagation of DMDEOS than DEM under stoichiometric and rich conditions, while the chemical effect exhibits a negative effect.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"270 ","pages":"Article 113795"},"PeriodicalIF":5.8,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142445587","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Laser-induced plasma analysis of ammonia-oxygen and ammonia-oxygen-enriched-air flames at elevated pressures","authors":"Bilge Kaan Gokcecik,&nbsp;Nagaraju Guthikonda,&nbsp;Aleksander Clark,&nbsp;Peng Zhao,&nbsp;Zhili Zhang","doi":"10.1016/j.combustflame.2024.113803","DOIUrl":"10.1016/j.combustflame.2024.113803","url":null,"abstract":"<div><div>This study employed Laser-induced breakdown spectroscopy (LIBS) to measure the fuel-oxidizer ratio (FOR) of ammonia combustion with oxygen-enriched air and pure oxygen flames at elevated pressures (100 - 300 kPa). The correlations between the spectral line intensity ratios of nitrogen (N), hydrogen (H), oxygen (O), and equivalence ratio were used to quantify the FOR of flames at various pressures. The effect of pressure on the stability and precision of the calibration profiles for the elemental intensity ratios in flames was investigated. It was observed that the H/O correlation decreases with pressure increase for both ammonia flames. N/O correlations decrease with elevated pressure for the ammonia-oxygen flame. Furthermore, the nitrogen (N_II) spectral emission lines at 568 nm and 595 nm were used to estimate the plasma temperature, while the hydrogen (H_α) line at 656 nm was used for electron number density measurements.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"271 ","pages":"Article 113803"},"PeriodicalIF":5.8,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142446722","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Parameter estimation of distributed activation energy models via chemical reaction neural network","authors":"Chunjie Zhai ,&nbsp;Xinmeng Wang ,&nbsp;Siyu Zhang ,&nbsp;Zhaolou Cao","doi":"10.1016/j.combustflame.2024.113798","DOIUrl":"10.1016/j.combustflame.2024.113798","url":null,"abstract":"<div><div>Kinetic parameter estimation is of fundamental importance in modeling the biomass pyrolysis process for biofuel production. In this work, a neural network architecture, named chemical reaction neural network (CRNN), was utilized to learn kinetic parameters (pre-exponential factor and distribution) in distributed activation energy models from the measurement of conversion rate without prior knowledge of the reaction. The Arrhenius equation is reformulated as the activation function of a neuron in the hidden layer of a three-layer neural network. The gradients of loss with respect to kinetic parameters can then be derived analytically, with which a gradient-based training algorithm is employed to optimize the kinetic parameters. The CRNN performance was evaluated based upon systematical numerical investigation of reactions with a double-Gaussian distribution function. The results show that by transforming the optimization problem into neural network training, the CRNN can accurately and efficiently recover the distribution and pre-exponential factor due to the embedded chemical knowledge. The applicability of CRNN in the pyrolysis of rice straw under different heating rates is examined by experimental measurements. It is shown that with the estimation provided the Kissinger method as the starting point, the CRNN is capable of reconstructing the conversion rate curve. We anticipate, as a feasible, efficient, and accurate model, the CRNN will benefit in enhancing the practice of biomass pyrolysis analysis.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"270 ","pages":"Article 113798"},"PeriodicalIF":5.8,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142440926","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental and modeling study of the oxidation of NH3/C2H4 mixtures in a shock tube","authors":"Shubao Song,&nbsp;Wanting Jia,&nbsp;Jiachen Sun,&nbsp;Cheng Wang,&nbsp;Jiankun Shao","doi":"10.1016/j.combustflame.2024.113777","DOIUrl":"10.1016/j.combustflame.2024.113777","url":null,"abstract":"&lt;div&gt;&lt;div&gt;Ammonia is a promising zero-carbon fuel, offering new possibilities for sustainable energy system development. In this study, ignition delay times (IDTs) of NH&lt;sub&gt;3&lt;/sub&gt;/C&lt;sub&gt;2&lt;/sub&gt;H&lt;sub&gt;4&lt;/sub&gt; mixtures with C&lt;sub&gt;2&lt;/sub&gt;H&lt;sub&gt;4&lt;/sub&gt; contents of 0 %, 5 %, 10 %, and 25 % were measured using a shock tube at temperatures ranging from 1176 to 1904 K, pressures of 1.0–8.5 atm, and equivalence ratios of 0.5, 1.0 and 2.0. A laser absorption diagnostic system was developed to track the temporal evolution of NH&lt;sub&gt;3&lt;/sub&gt; concentration during the oxidation process behind the reflected shock waves. The experimental results indicate that the IDTs of the mixtures exhibit non-linear decrease with the addition of ethylene. Specifically, compared to pure ammonia, the addition of 5 %, 10 % and 25 % ethylene significantly increases the reactivity of the mixture, leading to a 36.7 %, 75.9 % and 90.2 % reduction in IDT at a temperature of 1563 K and a pressure of 1.0 atm, respectively. Moreover, the mixture exhibits similar reactivity under fuel-lean and stoichiometric conditions, which remains higher than the reactivity observed under fuel-rich conditions. Overall, the IDTs and the time required for complete consumption of the mixture decreases as temperature, pressure, and ethylene blending ratio increase. In order to simulate and analyze the reaction process of NH&lt;sub&gt;3&lt;/sub&gt;/C&lt;sub&gt;2&lt;/sub&gt;H&lt;sub&gt;4&lt;/sub&gt; mixtures, a detailed kinetic model was constructed based on previous studies by updating the interaction reaction between C&lt;sub&gt;2&lt;/sub&gt;H&lt;sub&gt;4&lt;/sub&gt; and NH&lt;sub&gt;2&lt;/sub&gt; radical and validated against the current experimental results. Rate of production (ROP) and sensitivity analysis were performed to identify the primary consumption pathways of NH&lt;sub&gt;3&lt;/sub&gt;/C&lt;sub&gt;2&lt;/sub&gt;H&lt;sub&gt;4&lt;/sub&gt; and the significant impact of C&lt;sub&gt;2&lt;/sub&gt;H&lt;sub&gt;4&lt;/sub&gt; on the reactivity. Additionally, due to the addition of C&lt;sub&gt;2&lt;/sub&gt;H&lt;sub&gt;4&lt;/sub&gt;, a substantial amount of NH&lt;sub&gt;2&lt;/sub&gt; radical participates in the H-abstraction reaction (C&lt;sub&gt;2&lt;/sub&gt;H&lt;sub&gt;4&lt;/sub&gt; + NH&lt;sub&gt;2&lt;/sub&gt;&lt;=&gt;C&lt;sub&gt;2&lt;/sub&gt;H&lt;sub&gt;3&lt;/sub&gt; + NH&lt;sub&gt;3&lt;/sub&gt;). This results in a reduced involvement of NH&lt;sub&gt;2&lt;/sub&gt; in the DeNO&lt;sub&gt;x&lt;/sub&gt; process and, consequently, the NH&lt;sub&gt;3&lt;/sub&gt;/C&lt;sub&gt;2&lt;/sub&gt;H&lt;sub&gt;4&lt;/sub&gt; mixture exhibits a higher tendency to produce NO&lt;sub&gt;x&lt;/sub&gt; compared to pure ammonia.&lt;/div&gt;&lt;/div&gt;&lt;div&gt;&lt;h3&gt;Novelty and significance statement&lt;/h3&gt;&lt;div&gt;Ammonia offers new possibilities for sustainable energy systems but faces challenges like low combustion rate and mixing with reactive fuels can effectively enhance the ignition characteristics of NH&lt;sub&gt;3&lt;/sub&gt;. The ignition delay times and speciation NH&lt;sub&gt;3&lt;/sub&gt;/C&lt;sub&gt;2&lt;/sub&gt;H&lt;sub&gt;4&lt;/sub&gt; mixtures are systemically measured by using shock tube and laser absorption spectroscopy. A newly detailed kinetic NH&lt;sub&gt;3&lt;/sub&gt;-C&lt;sub&gt;2&lt;/sub&gt;H&lt;sub&gt;4&lt;/sub&gt; model is also developed based on previous studies by updating the interaction reaction between C&lt;sub","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"270 ","pages":""},"PeriodicalIF":5.8,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142441558","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Resident mechanism of a holder-stabilized ultra-lean hydrogen enriched residual flame","authors":"Wenquan Yang,&nbsp;Jianlong Wan","doi":"10.1016/j.combustflame.2024.113797","DOIUrl":"10.1016/j.combustflame.2024.113797","url":null,"abstract":"<div><div>The lean premixed combustion near the flammability limit is a promising technology to achieve cleaner and higher efficiency combustion of gaseous fuels. The residual flame usually occurs in the vicinity of the flammability limit. The deep insight into this flame behavior is crucial to further improve the lean premixed combustion performance. In the present study, the ultra-lean 40%H₂–60%CH₄-air premixed residual flame stabilized on the heat-conducting holder in a preheated micro burner is observed experimentally and numerically, and its resident mechanism is analyzed quantitatively in terms of the effects of the stretch, preferential transport, and conjugate heat transfer. The stretch and heat-loss effects do harm to the anchoring performance of the residual flame root. By contrast, the preferential transport effect contributes to maintaining it via generating the local fuel-richer region. This is why the flame root can still maintain although it suffers a higher stretch rate compared to the corresponding extinction strain rate of a planar flame. The small stretch and heat-loss effects as well as the noticeable preferential transport effect contribute to maintaining the residual flame tip. More critically, the preferential transport effect increases and heat-loss effect decreases when the equivalence ratio reduces, which ensures that the residual flame tip still can maintain at the ultra-low equivalence ratio. To the best of our knowledge, such a detailed main factors visualization of the stable residual flame has not been reported yet. The present study helps us to further understand the ultra-lean residual flame dynamics.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"270 ","pages":"Article 113797"},"PeriodicalIF":5.8,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142440856","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental and kinetic modeling study of cyclopentanone pyrolysis in a jet-stirred reactor","authors":"Hong Wang ,&nbsp;Bingzhi Liu ,&nbsp;Qiang Xu ,&nbsp;Shijun Dong ,&nbsp;Zhandong Wang ,&nbsp;Long Zhu","doi":"10.1016/j.combustflame.2024.113796","DOIUrl":"10.1016/j.combustflame.2024.113796","url":null,"abstract":"<div><div>Cyclopentanone (CPN) is a widely available biofuel with excellent combustion properties, but detailed speciation profiles during its pyrolysis have rarely been studied. This work examines the pyrolysis of CPN in a jet-stirred reactor (JSR) at atmospheric pressure, with residence time of 2 s and a temperature range from 830 K to 1100 K. Dozens of pyrolysis intermediates and products were measured using synchrotron vacuum ultraviolet photoionization mass spectrometry (SVUV-PIMS) and gas chromatography (GC). Among them, several new species were observed, including water, carbon dioxide, formaldehyde, indene, 1,2-dihydroindene, naphthalene, 1,2-dihydronaphthalene, 1-methylnaphthalene, acenaphthylene, biphenyl, and fluorene. A detailed kinetic model was developed based on the literature, and in general, it predicted the experimental results for most species well. Kinetic analyses indicated that the consumption of CPN was controlled by the bimolecular reactions with H atom. The formation of water, carbon dioxide and formaldehyde could be explained by the reaction pathways of OH radical. The pyrolysis of CPN yielded a significant number of alkenes and alkynes at higher temperatures; the bimolecular addition reactions of these species with resonantly stabilized radicals are important to the formation of polycyclic aromatic hydrocarbons (PAHs). Based on those, this work provides valuable insights into CPN pyrolysis chemistry and it promotes the development of a comprehensive CPN combustion model.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"270 ","pages":"Article 113796"},"PeriodicalIF":5.8,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142441195","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation on the dynamics of shock wave generated by detonation reflection","authors":"Zezhong Yang,&nbsp;Bo Zhang","doi":"10.1016/j.combustflame.2024.113791","DOIUrl":"10.1016/j.combustflame.2024.113791","url":null,"abstract":"<div><div>When a detonation wave hits a rigid wall, a reverse shock is created. This occurrence is common in closed pipe detonation experiments. To better comprehend the propagation dynamics of the reverse shock, experiments were performed in a 2.5-meter-long detonation tube. Normal reflection, Mach reflection, and regular reflection of detonation are generated by changing the end-wall profile. Three different mixtures, 2H₂+O₂+40%Ar (with very regular cellular pattern), C₂H₄+3O₂+40%Ar (regular), and CH₄+2O₂ (irregular), are used to examine how detonation stability affects the subsequent reflected shock propagation procedure. The reflection process is visualized by using a high-speed schlieren imaging technique. A one-dimensional simulation with a detailed chemical reaction mechanism was employed to further illustrate the dynamics of the reflected shock, which is generated by detonation normal reflection. Results show that the variation of the reflected shock speed in normal reflection can be categorized into three phases. First, the reflected shock speed rapidly decreases in the detonation reaction zone. It then slowly increases due to the transmitted expansion wave. Finally, the shock wave velocity gradually decreases in the stationary flow. A post-shock blast wave appears in the shocked but unburnt mixture. However, its impact on the reflected shock structure is minimal, as it attenuates drastically. The collision of the detonation and the shock-shock interaction at the tip of the reflectors boosts the reflected shock speed, and the acceleration ratio in the two regular mixtures is 33.7 %–48.7 %, while it is approximately 20 % in the irregular mixture. This study offers a fresh perspective on the complex detonation reflection process through the combined analysis of both experimental and numerical results.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"270 ","pages":"Article 113791"},"PeriodicalIF":5.8,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142440927","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fuel mobility dynamics and their influence on applied smouldering systems","authors":"Seyed Ziaedin Miry ,&nbsp;Marco A.B. Zanoni ,&nbsp;Tarek L. Rashwan ,&nbsp;Laura Kinsman ,&nbsp;José L. Torero ,&nbsp;Jason I. Gerhard","doi":"10.1016/j.combustflame.2024.113789","DOIUrl":"10.1016/j.combustflame.2024.113789","url":null,"abstract":"<div><div>Many recent environmentally beneficial applications of smouldering treat hazardous organic liquid fuels in inert porous media. In these applications, organic liquid mobilization can affect the treatment process, and the dynamics are poorly understood. Organic liquid mobilization is therefore a key knowledge gap that hinders the optimization of applied smouldering. This is especially the case in large scales where mobilization appears to be more significant. Liquid mobilization inside a porous medium cannot be easily measured directly, therefore numerical modelling is essential to understand the fundamental processes and to clarify the effects and dynamics of the fuel mobilization on the smouldering reaction. Contrasting numerical models with experimental temperature measurements have revealed many aspects of smouldering that cannot be measured. In this study, a previously developed 1D smouldering model was equipped with multiphase flow equations and compared against laboratory column experiments. The combination of model and experiments has served to quantify the dynamics of organic liquid fuel mobility by simulating high (i.e., non-mobile) and low (i.e., mobile) viscous fuels. The findings from this study shed light on the complicated interplay between multiphase flow, heat and mass transfer, and smoulder chemistry common to many applied smouldering systems. Numerical results confirmed that increasing the viscosity results in fuel remaining in the reaction zone and led to an increase in the peak temperature and smouldering front velocities. Lower viscosity fuels mobilized away from the reaction zone, thereby accumulating fuel in the pre-heating zone of the reactor. The fundamental understanding generated from this research will improve the design, implementation, and optimization of smouldering-based technologies for environmentally beneficial applications worldwide.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"270 ","pages":"Article 113789"},"PeriodicalIF":5.8,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142441559","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of AP and AN on the combustion and injection performance of Al-H2O gelled propellant","authors":"Songchen Yue ,&nbsp;Zhan Wen ,&nbsp;Qiu Wu ,&nbsp;Yao Shu ,&nbsp;Jian Jiang ,&nbsp;Peijin Liu ,&nbsp;Wen Ao","doi":"10.1016/j.combustflame.2024.113801","DOIUrl":"10.1016/j.combustflame.2024.113801","url":null,"abstract":"<div><div>Aluminum-water propellants (Al-H₂O propellants), representing a novel class of solid propellants, demonstrate the merits of cost efficiency and reduced feature signal characteristics. However, the conventional formulations of Al-H₂O propellants are hampered by the generation of substantial condensed residues. In our investigation, we explored the incorporation of oxidizers into the Al-H₂O propellant grain, aiming to enhance combustion and injection performance. Employing a multifaceted experimental approach, we conducted thermal gravimetric analysis, laser ignition experiments, and ignition tests within a lab-scale solid rocket motor (SRM) firing to systematically examine the effects of varying content of ammonium perchlorate (AP) and ammonium nitrate (AN) on the combustion and injection performance of Al-H₂O propellants. Our findings indicated that integrating AP and AN at a mass fraction of 3 % each notably curtailed ignition delay time by approximately 67 % and 90 %, respectively, and concurrently decreased burning rates by approximately 50 % and 58 %. Significantly, it has been observed that a composition incorporating a 5 % mass fraction of AP enhances the combustion efficiency of the Al-H₂O propellant system by approximately 2 %. Conversely, the integration of a 5 % mass fraction of AN into the same propellant matrix results in an augmentation of the injection efficiency by an estimated 47 %. Empirical evidence validating the augmentative impacts of AP and AN on the performance of Al-H₂O propellants has been substantiated through a series of motor hot firing experiments. Furthermore, the combustion behavior of Al-H₂O propellants has been elucidated through an analysis of the combustion physical mechanism of Al particles. The thermal decomposition of AP yields a substantial volume of oxidizing gases, which effectively accelerates the combustion rate of the Al particles, subsequently leading to an enhancement in the overall combustion efficiency of the propellant. Conversely, the decomposition of AN results in an increased production of nitrogen gas, thereby augmenting the velocity of gas flow and, consequently, elevating the injection efficiency of the propellant. This finding holds promise for guiding the developmental trajectory of Al-H₂O propellants and refining the design parameters of propulsion systems.</div></div>","PeriodicalId":280,"journal":{"name":"Combustion and Flame","volume":"270 ","pages":"Article 113801"},"PeriodicalIF":5.8,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142441560","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}