Pub Date : 2001-11-11DOI: 10.1115/imece2001/htd-24236
D. Crocker, J. Widmann, C. Presser
Validation of computational fluid dynamics (CFD) predictions for spray combustion application has been a challenging task due to difficulties in both modeling and experimental measurements. However, validation is considered to be an essential exercise for the success of CFD tools in the development of future combustion systems. This paper describes a benchmark spray combustion database collected at National Institute of Standards and Technology (NIST) and validation of a commercial CFD code using these data. Swirl-stabilized combustion of methanol at lean operating conditions in the NIST reference spray combustor facility was selected to be the baseline case for which both measurements and predictions were made. A comparison is presented of CFD predictions with experimental data for droplet size and velocity, and spray volume flux. The agreement between the CFD calculations and the experimental data is generally good once certain adjustments were made to the measured data close to the injector tip. The adjustments were made based on extrapolation from more accurate downstream measurements. Specification of droplet initial conditions for computational modeling that accurately reflect the laboratory conditions remains a significant issue that needs further improvement.
{"title":"CFD Modeling and Comparison With Data From the NIST Reference Spray Combustor","authors":"D. Crocker, J. Widmann, C. Presser","doi":"10.1115/imece2001/htd-24236","DOIUrl":"https://doi.org/10.1115/imece2001/htd-24236","url":null,"abstract":"\u0000 Validation of computational fluid dynamics (CFD) predictions for spray combustion application has been a challenging task due to difficulties in both modeling and experimental measurements. However, validation is considered to be an essential exercise for the success of CFD tools in the development of future combustion systems. This paper describes a benchmark spray combustion database collected at National Institute of Standards and Technology (NIST) and validation of a commercial CFD code using these data. Swirl-stabilized combustion of methanol at lean operating conditions in the NIST reference spray combustor facility was selected to be the baseline case for which both measurements and predictions were made. A comparison is presented of CFD predictions with experimental data for droplet size and velocity, and spray volume flux. The agreement between the CFD calculations and the experimental data is generally good once certain adjustments were made to the measured data close to the injector tip. The adjustments were made based on extrapolation from more accurate downstream measurements. Specification of droplet initial conditions for computational modeling that accurately reflect the laboratory conditions remains a significant issue that needs further improvement.","PeriodicalId":426926,"journal":{"name":"Heat Transfer: Volume 4 — Combustion and Energy Systems","volume":"148 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115409846","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}
Pub Date : 2001-11-11DOI: 10.1115/imece2001/htd-24251
K. McGrattan, J. Floyd, S. Hostikka
A numerical fire model, Fire Dynamics Simulator (FDS), is being developed at NIST to study fire behavior and to evaluate the performance of fire protection systems in buildings. To date, about half of the applications of the model have been for design of smoke handling systems and sprinkler/detector activation studies. The other half consists of residential and industrial fire reconstructions. Improvements are being made to address the second set of applications, most importantly a mixture fraction combustion model and a finite volume radiation transport algorithm using either a gray gas or a wide band assumption. The methods will be discussed and a sample calculation presented.
{"title":"A Mixture Fraction Combustion Model for Large Scale Fire Modeling","authors":"K. McGrattan, J. Floyd, S. Hostikka","doi":"10.1115/imece2001/htd-24251","DOIUrl":"https://doi.org/10.1115/imece2001/htd-24251","url":null,"abstract":"\u0000 A numerical fire model, Fire Dynamics Simulator (FDS), is being developed at NIST to study fire behavior and to evaluate the performance of fire protection systems in buildings. To date, about half of the applications of the model have been for design of smoke handling systems and sprinkler/detector activation studies. The other half consists of residential and industrial fire reconstructions. Improvements are being made to address the second set of applications, most importantly a mixture fraction combustion model and a finite volume radiation transport algorithm using either a gray gas or a wide band assumption. The methods will be discussed and a sample calculation presented.","PeriodicalId":426926,"journal":{"name":"Heat Transfer: Volume 4 — Combustion and Energy Systems","volume":"89 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116798962","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}
Pub Date : 2001-11-11DOI: 10.1115/imece2001/htd-24261
V. Travkin, K. Hu, I. Catton
Volume Averaging Theory (VAT), an effective and rigorous approach for study of transport (laminar and turbulent) phenomena, is used to model flow and heat transfer in porous media. The modeling is based on a simple pore level network. The primary difficulties in applying VAT to straight capillary networks, the many unknown integral and differential terms that are needed for closure, are overcome. VAT based modeling of pore level transport in straight capillaries results in two sets of scale governing equations. One scale is the upper scale VAT equations which describe ensemble properties for flow and heat transfer in porous media. The other scale is the lower scale laminar and turbulent transport equations that represent flow and heat transport in each straight pore capillary. It is how the unknown VAT terms in the upper scale equations can be estimated using the relationships between upper scale properties and lower scale properties. Exact closures and mathematical procedures are developed for the turbulent regime, extending the previous laminar regime work. Numerical results for turbulent and laminar transport in straight capillary porous media are shown in this paper.
{"title":"Exact Closure Procedures of Hierarchical VAT Capillary Thermo-Convective Problem for Turbulent and Laminar Regimes","authors":"V. Travkin, K. Hu, I. Catton","doi":"10.1115/imece2001/htd-24261","DOIUrl":"https://doi.org/10.1115/imece2001/htd-24261","url":null,"abstract":"\u0000 Volume Averaging Theory (VAT), an effective and rigorous approach for study of transport (laminar and turbulent) phenomena, is used to model flow and heat transfer in porous media. The modeling is based on a simple pore level network. The primary difficulties in applying VAT to straight capillary networks, the many unknown integral and differential terms that are needed for closure, are overcome. VAT based modeling of pore level transport in straight capillaries results in two sets of scale governing equations. One scale is the upper scale VAT equations which describe ensemble properties for flow and heat transfer in porous media. The other scale is the lower scale laminar and turbulent transport equations that represent flow and heat transport in each straight pore capillary. It is how the unknown VAT terms in the upper scale equations can be estimated using the relationships between upper scale properties and lower scale properties. Exact closures and mathematical procedures are developed for the turbulent regime, extending the previous laminar regime work. Numerical results for turbulent and laminar transport in straight capillary porous media are shown in this paper.","PeriodicalId":426926,"journal":{"name":"Heat Transfer: Volume 4 — Combustion and Energy Systems","volume":"117 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117215070","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}
Pub Date : 2001-11-11DOI: 10.1115/imece2001/htd-24279
A. Nnanna, K. T. Harris, A. Haji-sheikh
An experimental validation of non-Fourier behavior in porous media due to short time thermal perturbation is presented. The governing energy equation is formulated based on the two-equation model and the non-Fourier model. This formulation leads to the emergence of four thermal parameters: lag-time in heat flux τq, lag-time τt in temperature due to interstitial heat transfer coefficient h, and lag-time in the transient response of the temperature gradient τx in the heat flux equation. These parameters account for the microstructural thermal interaction between the fluid and neighboring solid matrix as well as the delay time needed for both phases to approach thermal equilibrium. An experimental verification of the microscale model was performed under standard laboratory conditions. The values of the aforementioned thermal parameters were determined to compute the fluid and solid temperatures. Results predicted from three models (classical Fourier, non-Fourier, and experimental) were compared. It indicates an excellent agreement between the non-Fourier and the experimental model, and a significant deviation of Fourier prediction from the experimental results.
{"title":"Experimental Validation of Non-Fourier Thermal Response in Porous Media","authors":"A. Nnanna, K. T. Harris, A. Haji-sheikh","doi":"10.1115/imece2001/htd-24279","DOIUrl":"https://doi.org/10.1115/imece2001/htd-24279","url":null,"abstract":"\u0000 An experimental validation of non-Fourier behavior in porous media due to short time thermal perturbation is presented. The governing energy equation is formulated based on the two-equation model and the non-Fourier model. This formulation leads to the emergence of four thermal parameters: lag-time in heat flux τq, lag-time τt in temperature due to interstitial heat transfer coefficient h, and lag-time in the transient response of the temperature gradient τx in the heat flux equation. These parameters account for the microstructural thermal interaction between the fluid and neighboring solid matrix as well as the delay time needed for both phases to approach thermal equilibrium. An experimental verification of the microscale model was performed under standard laboratory conditions. The values of the aforementioned thermal parameters were determined to compute the fluid and solid temperatures. Results predicted from three models (classical Fourier, non-Fourier, and experimental) were compared. It indicates an excellent agreement between the non-Fourier and the experimental model, and a significant deviation of Fourier prediction from the experimental results.","PeriodicalId":426926,"journal":{"name":"Heat Transfer: Volume 4 — Combustion and Energy Systems","volume":"64 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125668833","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}
Pub Date : 2001-11-11DOI: 10.1115/imece2001/htd-24243
F. Battaglia, R. Rehm, H. Baum, Mohamed I. Hassan, Kozo Saito
Perhaps the most dramatic example of surprising behavior when circulation is imposed on a combustion-driven flow is the fire whirl, where the burning gases form a tall slender column. Relatively few studies have addressed the influence of circulation on the development of combustion-driven flows. Three dimensionless parameters characterize this interplay: the Froude number, the swirl number and the Reynolds number. It is surprising that for most studies, even with plausible assumptions concerning the experiments, not enough information is given to determine the values of these parameters. We will experimentally reconstruct these studies in an effort to characterize parametrically these interactions. Both buoyancy-driven and momentum-driven combustion processes will be investigated to determine the influence of circulation. Theoretical studies will occur in conjunction to provide the most complete parametric investigation.
{"title":"A Perspective on Combustion-Driven Flows With Circulation","authors":"F. Battaglia, R. Rehm, H. Baum, Mohamed I. Hassan, Kozo Saito","doi":"10.1115/imece2001/htd-24243","DOIUrl":"https://doi.org/10.1115/imece2001/htd-24243","url":null,"abstract":"\u0000 Perhaps the most dramatic example of surprising behavior when circulation is imposed on a combustion-driven flow is the fire whirl, where the burning gases form a tall slender column. Relatively few studies have addressed the influence of circulation on the development of combustion-driven flows. Three dimensionless parameters characterize this interplay: the Froude number, the swirl number and the Reynolds number. It is surprising that for most studies, even with plausible assumptions concerning the experiments, not enough information is given to determine the values of these parameters. We will experimentally reconstruct these studies in an effort to characterize parametrically these interactions. Both buoyancy-driven and momentum-driven combustion processes will be investigated to determine the influence of circulation. Theoretical studies will occur in conjunction to provide the most complete parametric investigation.","PeriodicalId":426926,"journal":{"name":"Heat Transfer: Volume 4 — Combustion and Energy Systems","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130138312","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}
Pub Date : 2001-11-11DOI: 10.1115/imece2001/htd-24240
R. Vance, I. Wichman
A linear stability analysis is performed on two simplified models representing a one-dimensional flame between oxidizer and fuel reservoirs and a two-dimensional “edge-flame” between the same reservoirs but above a cold, inert wall. Comparison of the eigenvalue spectra for both models is performed to discern the validity of extending the results from the one-dimensional problem to the two-dimensional problem. Of primary interest is the influence on flame stability of thermal-diffusive imbalances, i.e. non-unity Lewis numbers. Flame oscillations are observed when Le > 1, and cellular flames are witnessed when Le < 1. It is found that when Le > 1 the characteristics of flame behavior are consistent between the two models. Furthermore, when Le < 1, the models are found to be in good agreement with respect to the magnitude of the critical wave numbers. Results from the coarse mesh analysis of the two-dimensional system are presented and compared to the one-dimensional eigenvalue spectra. Additionally, an examination of low reactant convection is undertaken. It is concluded that for low flow rates the behavior in one and two dimensions are similar qualitatively and quantitatively.
{"title":"A Comparison of Diffusion Flame Stability in One and Two Spatial Dimensions Near Cold, Inert Surfaces","authors":"R. Vance, I. Wichman","doi":"10.1115/imece2001/htd-24240","DOIUrl":"https://doi.org/10.1115/imece2001/htd-24240","url":null,"abstract":"\u0000 A linear stability analysis is performed on two simplified models representing a one-dimensional flame between oxidizer and fuel reservoirs and a two-dimensional “edge-flame” between the same reservoirs but above a cold, inert wall. Comparison of the eigenvalue spectra for both models is performed to discern the validity of extending the results from the one-dimensional problem to the two-dimensional problem. Of primary interest is the influence on flame stability of thermal-diffusive imbalances, i.e. non-unity Lewis numbers. Flame oscillations are observed when Le > 1, and cellular flames are witnessed when Le < 1. It is found that when Le > 1 the characteristics of flame behavior are consistent between the two models. Furthermore, when Le < 1, the models are found to be in good agreement with respect to the magnitude of the critical wave numbers. Results from the coarse mesh analysis of the two-dimensional system are presented and compared to the one-dimensional eigenvalue spectra. Additionally, an examination of low reactant convection is undertaken. It is concluded that for low flow rates the behavior in one and two dimensions are similar qualitatively and quantitatively.","PeriodicalId":426926,"journal":{"name":"Heat Transfer: Volume 4 — Combustion and Energy Systems","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116001108","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}
Pub Date : 2001-11-11DOI: 10.1115/imece2001/htd-24252
R. Vance, I. Wichman
The profile of a spreading flamelet is analyzed by examining the heat losses to surrounding surfaces. The study addresses the reasons why flamelets have shapes ranging from round hemispherical “caps” to flat “coin-like” discs. A parabolic shape profile is used for the thin flame sheet, which provides both flame length and flame curvature. A third parameter specifies the height of the flame from the surface beneath it. Radiation and conduction heat losses from the flame sheet are calculated for various flame shapes. Overall heat losses as well as heat losses to the surface beneath the flamelet are examined. Some of the heat “losses” are misnamed because they produce the necessary surface decomposition for subsequent gaseous flame fuel vapors. Strictly, then, “losses” do not contribute appreciably to the maintenance of the flame. Physical arguments are made to explain observed flame spread behavior and flame shapes in response to prevailing flow and environmental conditions.
{"title":"Heat Loss Analysis of Flamelets in Near-Limit Spread Over Solid Fuel Surfaces","authors":"R. Vance, I. Wichman","doi":"10.1115/imece2001/htd-24252","DOIUrl":"https://doi.org/10.1115/imece2001/htd-24252","url":null,"abstract":"\u0000 The profile of a spreading flamelet is analyzed by examining the heat losses to surrounding surfaces. The study addresses the reasons why flamelets have shapes ranging from round hemispherical “caps” to flat “coin-like” discs. A parabolic shape profile is used for the thin flame sheet, which provides both flame length and flame curvature. A third parameter specifies the height of the flame from the surface beneath it. Radiation and conduction heat losses from the flame sheet are calculated for various flame shapes. Overall heat losses as well as heat losses to the surface beneath the flamelet are examined. Some of the heat “losses” are misnamed because they produce the necessary surface decomposition for subsequent gaseous flame fuel vapors. Strictly, then, “losses” do not contribute appreciably to the maintenance of the flame. Physical arguments are made to explain observed flame spread behavior and flame shapes in response to prevailing flow and environmental conditions.","PeriodicalId":426926,"journal":{"name":"Heat Transfer: Volume 4 — Combustion and Energy Systems","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121315115","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}
Pub Date : 2001-11-11DOI: 10.1115/imece2001/htd-24275
M. Whale
The non-Planckian spectrum of microscale thermal radiation is interpreted using a formulation for non-thermal radiation. The non-thermal aspects of the energy spectrum that results when radiating bodies are in close proximity are examined using the fluctuational electrodynamic approach to microscale thermal radiation. A definition of the effective flux temperature for microscale thermal radiation is presented. A technique to determine the entropy flux in a microscale field is obtained and used to calculate the effective flux temperature for chromium surfaces. The effective flux temperature of microscale radiation permits an assessment of the limits of the performance of proposed devices for the exploitation the spacing effect for energy conversion. The performance of a microscale thermophotovoltaic device is examined in terms of this flux temperature.
{"title":"Effective Flux Temperature Formulation for Energy Conversion Using Microscale Thermal Radiation","authors":"M. Whale","doi":"10.1115/imece2001/htd-24275","DOIUrl":"https://doi.org/10.1115/imece2001/htd-24275","url":null,"abstract":"\u0000 The non-Planckian spectrum of microscale thermal radiation is interpreted using a formulation for non-thermal radiation. The non-thermal aspects of the energy spectrum that results when radiating bodies are in close proximity are examined using the fluctuational electrodynamic approach to microscale thermal radiation. A definition of the effective flux temperature for microscale thermal radiation is presented. A technique to determine the entropy flux in a microscale field is obtained and used to calculate the effective flux temperature for chromium surfaces. The effective flux temperature of microscale radiation permits an assessment of the limits of the performance of proposed devices for the exploitation the spacing effect for energy conversion. The performance of a microscale thermophotovoltaic device is examined in terms of this flux temperature.","PeriodicalId":426926,"journal":{"name":"Heat Transfer: Volume 4 — Combustion and Energy Systems","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125181282","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}
Pub Date : 2001-11-11DOI: 10.1115/imece2001/htd-24250
M. Kramer, M. Greiner, J. Koski
A series of large-scale experiments were recently performed to measure heat transfer to a massive cylindrical calorimeter engulfed in a 30-minute circular-pool fire [1]. The calorimeter inner surface temperature was measured at several locations and an inverse conduction technique was used to determine the net heat flux. The flame emissive heat flux was measured at several locations around the calorimeter. Light winds of around 2 m/s blew across the calorimeter axis at the beginning of the test but diminished and stopped as the test continued. The winds tilted the fire so that the windward side of the calorimeter was only intermittently engulfed. As a result, the measured flame emissive power near the windward side was substantially less than the leeward surface. The variation of calorimeter temperature and heat flux was closely correlated with the measured flame emissive power.
{"title":"Radiation Heat Transfer to the Leeward Side of a Massive Object Suspended Over a Pool Fire","authors":"M. Kramer, M. Greiner, J. Koski","doi":"10.1115/imece2001/htd-24250","DOIUrl":"https://doi.org/10.1115/imece2001/htd-24250","url":null,"abstract":"\u0000 A series of large-scale experiments were recently performed to measure heat transfer to a massive cylindrical calorimeter engulfed in a 30-minute circular-pool fire [1]. The calorimeter inner surface temperature was measured at several locations and an inverse conduction technique was used to determine the net heat flux. The flame emissive heat flux was measured at several locations around the calorimeter. Light winds of around 2 m/s blew across the calorimeter axis at the beginning of the test but diminished and stopped as the test continued. The winds tilted the fire so that the windward side of the calorimeter was only intermittently engulfed. As a result, the measured flame emissive power near the windward side was substantially less than the leeward surface. The variation of calorimeter temperature and heat flux was closely correlated with the measured flame emissive power.","PeriodicalId":426926,"journal":{"name":"Heat Transfer: Volume 4 — Combustion and Energy Systems","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116520164","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}
Pub Date : 2001-11-11DOI: 10.1115/imece2001/htd-24233
G. Goldin, D. Choudhury
Two steady-state simulations of a benchmark (Sandia Flame D) methane-air, turbulent, partially premixed flame are compared. The first uses an equilibrium mixture fraction model for the thermo-chemistry, while the second uses a steady, strained laminar-flamelet model. These non-premixed combustion models are coupled with a premixed reaction progress model to simulate a partially premixed jet flame. The laminar-flamelet approach predicts CO and H2 more accurately than the equilibrium model by accounting for the unbumt premixed stream within individual flamelets, and improved radical (such as OH) predictions by incorporating non-equilibrium chemistry effects due aerodynamic strain (fluid shear).
{"title":"Steady-State Simulation of a Methane-Air Partially Premixed Turbulent Flame","authors":"G. Goldin, D. Choudhury","doi":"10.1115/imece2001/htd-24233","DOIUrl":"https://doi.org/10.1115/imece2001/htd-24233","url":null,"abstract":"\u0000 Two steady-state simulations of a benchmark (Sandia Flame D) methane-air, turbulent, partially premixed flame are compared. The first uses an equilibrium mixture fraction model for the thermo-chemistry, while the second uses a steady, strained laminar-flamelet model. These non-premixed combustion models are coupled with a premixed reaction progress model to simulate a partially premixed jet flame. The laminar-flamelet approach predicts CO and H2 more accurately than the equilibrium model by accounting for the unbumt premixed stream within individual flamelets, and improved radical (such as OH) predictions by incorporating non-equilibrium chemistry effects due aerodynamic strain (fluid shear).","PeriodicalId":426926,"journal":{"name":"Heat Transfer: Volume 4 — Combustion and Energy Systems","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132746447","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}
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