Journal of Combustion最新文献_第8页

Effects of Electric Field on the SHS Flame Propagation of the Si-C System, Examined by the Use of the Heterogeneous Theory 电场对Si-C系统SHS火焰传播的影响，用非均相理论研究

IF 0.7

Journal of Combustion Pub Date : 2013-09-24 DOI: 10.1155/2013/752068

A. Makino

{"title":"Effects of Electric Field on the SHS Flame Propagation of the Si-C System, Examined by the Use of the Heterogeneous Theory","authors":"A. Makino","doi":"10.1155/2013/752068","DOIUrl":"https://doi.org/10.1155/2013/752068","url":null,"abstract":"Relevant to the self-propagating high-temperature synthesis (SHS) process, an analytical study has been conducted to investigate the effects of electric field on the combustion behavior because the electric field is indispensable for systems with weak exothermic reactions to sustain flame propagation. In the present study, use has been made of the heterogeneous theory which can satisfactorily account for the premixed mode of the bulk flame propagation supported by the nonpremixed mode of particle consumption. It has been confirmed that, even for the SHS flame propagation under electric field, being well recognized to be facilitated, there exists a limit of flammability, due to heat loss, as is the case for the usual SHS flame propagation. Since the heat loss is closely related to the representative sizes of particles and compacted specimen, this identification provides useful insight into manipulating the SHS flame propagation under electric field, by presenting appropriate combinations of those sizes. A fair degree of agreement has been demonstrated through conducting an experimental comparison, as far as the trend and the approximate magnitude are concerned, suggesting that an essential feature has been captured by the present study.","PeriodicalId":44364,"journal":{"name":"Journal of Combustion","volume":"146 1","pages":"1-8"},"PeriodicalIF":0.7,"publicationDate":"2013-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90374928","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}

引用次数: 1

A Comparison of the Characteristics of Planar and Axisymmetric Bluff-Body Combustors Operated under Stratified Inlet Mixture Conditions 分层进口混合气条件下平面与轴对称钝体燃烧室特性比较

IF 0.7

Journal of Combustion Pub Date : 2013-09-10 DOI: 10.1155/2013/860508

G. Paterakis, K. Souflas, E. Dogkas, P. Koutmos

{"title":"A Comparison of the Characteristics of Planar and Axisymmetric Bluff-Body Combustors Operated under Stratified Inlet Mixture Conditions","authors":"G. Paterakis, K. Souflas, E. Dogkas, P. Koutmos","doi":"10.1155/2013/860508","DOIUrl":"https://doi.org/10.1155/2013/860508","url":null,"abstract":"The work presents comparisons of the flame stabilization characteristics of axisymmetric disk and 2D slender bluff-body burner configurations, operating with inlet mixture stratification, under ultralean conditions. A double cavity propane air premixer formed along three concentric disks, supplied with a radial equivalence ratio gradient the afterbody disk recirculation, where the first flame configuration is stabilized. Planar fuel injection along the center plane of the leading face of a slender square cylinder against the approach cross-flow results in a stratified flame configuration stabilized alongside the wake formation region in the second setup. Measurements of velocities, temperatures, and chemiluminescence, local extinction criteria, and large-eddy simulations are employed to examine a range of ultralean and close to extinction flame conditions. The variations of the reacting front disposition within these diverse reacting wake topologies, the effect of the successive suppression of heat release on the near flame region characteristics, and the reemergence of large-scale vortical activity on approach to lean blowoff (LBO) are investigated. The cross-correlation of the performance of these two popular flame holders that are at the opposite ends of current applications might offer helpful insights into more effective control measures for expanding the operational margin of a wider range of stabilization configurations.","PeriodicalId":44364,"journal":{"name":"Journal of Combustion","volume":"35 1","pages":"1-15"},"PeriodicalIF":0.7,"publicationDate":"2013-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89380216","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}

引用次数: 1

Homogeneous Charge Compression Ignition Combustion: Challenges and Proposed Solutions 均质压缩点火燃烧:挑战和建议的解决方案

IF 0.7

Journal of Combustion Pub Date : 2013-08-26 DOI: 10.1155/2013/783789

M. I. Najafabadi, N. Aziz

{"title":"Homogeneous Charge Compression Ignition Combustion: Challenges and Proposed Solutions","authors":"M. I. Najafabadi, N. Aziz","doi":"10.1155/2013/783789","DOIUrl":"https://doi.org/10.1155/2013/783789","url":null,"abstract":"Engine and car manufacturers are experiencing the demand concerning fuel efficiency and low emissions from both consumers and governments. Homogeneous charge compression ignition (HCCI) is an alternative combustion technology that is cleaner and more efficient than the other types of combustion. Although the thermal efficiency and emission of HCCI engine are greater in comparison with traditional engines, HCCI combustion has several main difficulties such as controlling of ignition timing, limited power output, and weak cold-start capability. In this study a literature review on HCCI engine has been performed and HCCI challenges and proposed solutions have been investigated from the point view of Ignition Timing that is the main problem of this engine. HCCI challenges are investigated by many IC engine researchers during the last decade, but practical solutions have not been presented for a fully HCCI engine. Some of the solutions are slow response time and some of them are technically difficult to implement. So it seems that fully HCCI engine needs more investigation to meet its mass-production and the future research and application should be considered as part of an effort to achieve low-temperature combustion in a wide range of operating conditions in an IC engine.","PeriodicalId":44364,"journal":{"name":"Journal of Combustion","volume":"40 1","pages":"783789"},"PeriodicalIF":0.7,"publicationDate":"2013-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87751796","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}

引用次数: 49

The Principal Aspects of Application of Detonation in Propulsion Systems 爆轰在推进系统中应用的主要方面

IF 0.7

Journal of Combustion Pub Date : 2013-06-20 DOI: 10.1155/2013/945161

A. Vasil’ev

引用次数: 8

Measurements of Gasification Characteristics of Coal and Char in CO2-Rich Gas Flow by TG-DTA 用TG-DTA测定煤和炭在富co2气流中的气化特性

IF 0.7

Journal of Combustion Pub Date : 2013-06-02 DOI: 10.1155/2013/985687

Zhigang Li, Xiaoming Zhang, Y. Sugai, Jiren Wang, K. Sasaki

引用次数: 5

Characteristics of Flameless Combustion in 3D Highly Porous Reactors under Diesel Injection Conditions 柴油喷射条件下三维高多孔反应器无焰燃烧特性研究

IF 0.7

Journal of Combustion Pub Date : 2013-05-23 DOI: 10.1155/2013/267631

M. Węcłaś, J. Cypris

{"title":"Characteristics of Flameless Combustion in 3D Highly Porous Reactors under Diesel Injection Conditions","authors":"M. Węcłaś, J. Cypris","doi":"10.1155/2013/267631","DOIUrl":"https://doi.org/10.1155/2013/267631","url":null,"abstract":"The heat release process in a free volume combustion chamber and in porous reactors has been analyzed under Diesel engine-like conditions. The process has been investigated in a wide range of initial pressures and temperatures simulating engine conditions at the moment when fuel injection starts. The resulting pressure history in both porous reactors and in free volumes significantly depends on the initial pressure and temperature. At lower initial temperatures, the process in porous reactors is accelerated. Combustion in a porous reactor is characterized by heat accumulation in the solid phase of the porous structure and results in reduced pressure peaks and lowered combustion temperature. This depends on reactor heat capacity, pore density, specific surface area, pore structure, and heat transport properties. Characteristic modes of a heat release process in a two-dimensional field of initial pressure and temperature have been selected. There are three characteristic regions represented by a single- and multistep oxidation process (with two or three slopes in the reaction curve) and characteristic delay time distribution has been selected in five characteristic ranges. There is a clear qualitative similarity of characteristic modes of the heat release process in a free volume and in porous reactors. A quantitative influence of porous reactor features (heat capacity, pore density, pore structure, specific surface area, and fuel distribution in the reactor volume) has been clearly indicated.","PeriodicalId":44364,"journal":{"name":"Journal of Combustion","volume":"44 1","pages":"1-22"},"PeriodicalIF":0.7,"publicationDate":"2013-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81134976","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}

引用次数: 4

Combustion Rate of Solid Carbon in the Axisymmetric Stagnation Flowfield Established over a Sphere and/or a Flat Plate 在球体和/或平板上建立的轴对称停滞流场中固体碳的燃烧速率

IF 0.7

Journal of Combustion Pub Date : 2013-04-23 DOI: 10.1155/2013/790672

A. Makino, M. Hojo, Masahito Shintomi

{"title":"Combustion Rate of Solid Carbon in the Axisymmetric Stagnation Flowfield Established over a Sphere and/or a Flat Plate","authors":"A. Makino, M. Hojo, Masahito Shintomi","doi":"10.1155/2013/790672","DOIUrl":"https://doi.org/10.1155/2013/790672","url":null,"abstract":"Carbon combustion in the forward stagnation flowfield has been examined through experimental comparisons, by conducting aerothermochemical analyses, with the surface C-O2 and C-CO2 reactions and the gas-phase CO-O2 reaction taken into account. By virtue of the generalized species-enthalpy coupling functions, close coupling of those reactions has been elucidated. Explicit combustion-rate expressions by use of the transfer number in terms of the natural logarithmic term, just like that for droplet combustion, have further been obtained for the combustion response in the limiting situations. It has been confirmed that before the establishment of CO flame, the combustion rate can fairly be represented by the expression in the frozen mode, that after its establishment by the expression in the flame-attached or flame-detached modes, and that the critical condition derived by the asymptotics can fairly predict the surface temperature for its establishment. The formulation has further been extended to include the surface C-H2O and gas-phase H2-O2 reactions additionally, so as to evaluate the combustion rate in humid airflow. Since those expressions are explicit and have fair accuracy, they are anticipated to make various contributions not only for qualitative/quantitative studies, but also for various aerospace applications, including propulsion with high-energy-density fuels.","PeriodicalId":44364,"journal":{"name":"Journal of Combustion","volume":"148 1","pages":"1-22"},"PeriodicalIF":0.7,"publicationDate":"2013-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77360811","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}

引用次数: 1

Combustion of Submillimeter Heptane/Methanol and Heptane/Ethanol Droplets in Reduced Gravity 亚毫米级庚烷/甲醇和庚烷/乙醇液滴在失重条件下的燃烧

IF 0.7

Journal of Combustion Pub Date : 2013-02-12 DOI: 10.1155/2013/154202

I. Aharon, V. K. Tam, B. Shaw

引用次数: 9

Interactive Combustion in a Linear Array of 2D Laminar Isolated and Triple Burner Jets 二维层流隔离和三燃烧器射流线性阵列中的相互作用燃烧

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Journal of Combustion Pub Date : 2012-11-19 DOI: 10.1155/2012/716050

S. Tillman, S. Kuchibhatla, K. Annamalai, J. Caton, Devesh Ranjan

{"title":"Interactive Combustion in a Linear Array of 2D Laminar Isolated and Triple Burner Jets","authors":"S. Tillman, S. Kuchibhatla, K. Annamalai, J. Caton, Devesh Ranjan","doi":"10.1155/2012/716050","DOIUrl":"https://doi.org/10.1155/2012/716050","url":null,"abstract":"Many practical combustion systems such as residential gas burners contain dense groupings or clusters of jet flames with sufficiently small spacing between them, which causes flame interaction. The interaction effect, due in part to Oxygen deficiency in the interstitial space between the flames, causes the spreading of flames, which may merge together to form larger group flames. This interactive effect is studied analytically by revisiting the laminar isolated flame theory for 2D jets, for which similarity solutions are readily available in compressible form, and symmetrical interaction zones can be observed. Flame characteristics were studied by obtaining analytical expressions for flame specific parameters such as height and width, lift-off height and blow-off velocity, air entrainment and mixing layer growth. The theory for multiple interacting jets describes an approximate criterion for interburner spacing at which flame interaction and group flame formation are first observed. The analytical framework presented in this paper presented in this paper produced results which were compared with experimental measurements. The experimental apparatus allowed the interburner spacing to be varied from 7.87 mm to 50.8 mm, and measurements of flame height, width, lift-off height and group-flame formation under interactive modes. Images of the evolving flow field were taken and Schlieren images of the multiple 2D jets were also recorded using a digital camera.","PeriodicalId":44364,"journal":{"name":"Journal of Combustion","volume":"216 1","pages":"1-22"},"PeriodicalIF":0.7,"publicationDate":"2012-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75564641","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}

引用次数: 5

Modelling of the Curvature Term of the Flame Surface Density Transport Equation for Large Eddy Simulations 大涡模拟中火焰表面密度输运方程曲率项的建模

IF 0.7

Journal of Combustion Pub Date : 2012-11-07 DOI: 10.1155/2012/915482

M. Katragadda, N. Chakraborty

{"title":"Modelling of the Curvature Term of the Flame Surface Density Transport Equation for Large Eddy Simulations","authors":"M. Katragadda, N. Chakraborty","doi":"10.1155/2012/915482","DOIUrl":"https://doi.org/10.1155/2012/915482","url":null,"abstract":"A simplified chemistry based three-dimensional Direct Numerical Simulation (DNS) database of freely propagating statistically planar turbulent premixed flames with a range of different values of turbulent Reynolds number has been used for the a priori modelling of the curvature term of the generalised Flame Surface Density (FSD) transport equation in the context of Large Eddy Simulation (LES). The curvature term has been split into the contributions arising due to the reaction and normal diffusion components of displacement speed and the term originating from the tangential diffusion component of displacement speed. Subsequently, these contributions of the curvature term have been split into the resolved and subgrid contributions. New models have been proposed for the subgrid curvature terms arising from the combined reaction and normal diffusion components and the tangential diffusion component of displacement speed. The performances of the new model and the existing models for the subgrid curvature term have been compared with the corresponding quantity extracted from the explicitly filtered DNS data. The new model for the subgrid curvature term is shown to perform satisfactorily in all cases considered in the current study, accounting for wide variations in LES filter size.","PeriodicalId":44364,"journal":{"name":"Journal of Combustion","volume":"25 1","pages":"1-12"},"PeriodicalIF":0.7,"publicationDate":"2012-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90955455","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}

引用次数: 3