Author: Amin Akbari
Publisher:
ISBN: 9781124381060
Category :
Languages : en
Pages : 167
Book Description
The mixing of fuel and air has a significant impact on overall operation efficiency and emissions performance of combustion systems, especially in lean combustion applications. As a result, developing an understanding of the processes associated with the fuel/air mixing is important. In parallel with the evolution of lean combustion, a new generation of fuels is emerging as an alternative to conventional fuels. Thus, it is desirable to study the mixing properties of different fuels from conventional resources, such as methane, as well as from renewable resources, such as hydrogen. One tool that is available to study mixing in complex (e.g., turbulent and elliptic) flows is computational fluid dynamics (CFD). In the present work, mixing of hydrogen and methane into air, for example, is simulated using various CFD approaches. Fuel is injected either co-flowing to the air flow ("axial injection") or perpendicular to the air flow ("radial injection"). The quality of the simulations is evaluated by comparing the numerical results with experimental measurements. Qualitative and quantitative comparisons are used to evaluate the relative accuracy of different CFD approaches to simulate the mixing characteristics. Reynolds Averaged Navier-Stokes (RANS) turbulent models are utilized to model all the cases as steady turbulent models. Moreover, unsteady turbulent models, such as Unsteady RANS, and Large Eddy Simulation (LES) are used to provide information about unsteady features in selected cases. The sensitivity of numerical predictions to different RANS turbulence models as well as to different turbulent Schmidt numbers are explored. The results indicate more sensitivity to turbulence models for radial injection configurations. However, for the axial configuration, more sensitivity to Sct is observed. In general, the RSM turbulence model with Sct=0.7 provides the most promising predictions for various combination of different fuels and injection types.
Numerical and Experimental Study of Mixing Properties of Gaseous Fuels Jets Including Hydrogen and Methane Into the Non-swirl Main Flow in a Premixer Configuration
Author: Amin Akbari
Publisher:
ISBN: 9781124381060
Category :
Languages : en
Pages : 167
Book Description
The mixing of fuel and air has a significant impact on overall operation efficiency and emissions performance of combustion systems, especially in lean combustion applications. As a result, developing an understanding of the processes associated with the fuel/air mixing is important. In parallel with the evolution of lean combustion, a new generation of fuels is emerging as an alternative to conventional fuels. Thus, it is desirable to study the mixing properties of different fuels from conventional resources, such as methane, as well as from renewable resources, such as hydrogen. One tool that is available to study mixing in complex (e.g., turbulent and elliptic) flows is computational fluid dynamics (CFD). In the present work, mixing of hydrogen and methane into air, for example, is simulated using various CFD approaches. Fuel is injected either co-flowing to the air flow ("axial injection") or perpendicular to the air flow ("radial injection"). The quality of the simulations is evaluated by comparing the numerical results with experimental measurements. Qualitative and quantitative comparisons are used to evaluate the relative accuracy of different CFD approaches to simulate the mixing characteristics. Reynolds Averaged Navier-Stokes (RANS) turbulent models are utilized to model all the cases as steady turbulent models. Moreover, unsteady turbulent models, such as Unsteady RANS, and Large Eddy Simulation (LES) are used to provide information about unsteady features in selected cases. The sensitivity of numerical predictions to different RANS turbulence models as well as to different turbulent Schmidt numbers are explored. The results indicate more sensitivity to turbulence models for radial injection configurations. However, for the axial configuration, more sensitivity to Sct is observed. In general, the RSM turbulence model with Sct=0.7 provides the most promising predictions for various combination of different fuels and injection types.
Publisher:
ISBN: 9781124381060
Category :
Languages : en
Pages : 167
Book Description
The mixing of fuel and air has a significant impact on overall operation efficiency and emissions performance of combustion systems, especially in lean combustion applications. As a result, developing an understanding of the processes associated with the fuel/air mixing is important. In parallel with the evolution of lean combustion, a new generation of fuels is emerging as an alternative to conventional fuels. Thus, it is desirable to study the mixing properties of different fuels from conventional resources, such as methane, as well as from renewable resources, such as hydrogen. One tool that is available to study mixing in complex (e.g., turbulent and elliptic) flows is computational fluid dynamics (CFD). In the present work, mixing of hydrogen and methane into air, for example, is simulated using various CFD approaches. Fuel is injected either co-flowing to the air flow ("axial injection") or perpendicular to the air flow ("radial injection"). The quality of the simulations is evaluated by comparing the numerical results with experimental measurements. Qualitative and quantitative comparisons are used to evaluate the relative accuracy of different CFD approaches to simulate the mixing characteristics. Reynolds Averaged Navier-Stokes (RANS) turbulent models are utilized to model all the cases as steady turbulent models. Moreover, unsteady turbulent models, such as Unsteady RANS, and Large Eddy Simulation (LES) are used to provide information about unsteady features in selected cases. The sensitivity of numerical predictions to different RANS turbulence models as well as to different turbulent Schmidt numbers are explored. The results indicate more sensitivity to turbulence models for radial injection configurations. However, for the axial configuration, more sensitivity to Sct is observed. In general, the RSM turbulence model with Sct=0.7 provides the most promising predictions for various combination of different fuels and injection types.
Study of Ing Properties of Gaseous Fuels Jets in a Premixer
Author: Amin Akbari
Publisher: LAP Lambert Academic Publishing
ISBN: 9783848486052
Category :
Languages : en
Pages : 176
Book Description
In the present work, mixing of hydrogen and methane into air is simulated using various CFD approaches. Fuel is injected either co-flowing to the air flow ( axial injection ) or perpendicular to the air flow ( radial injection ). The quality of the simulations is evaluated by comparing the numerical results with experimental measurements. Qualitative and quantitative comparisons are used to evaluate the relative accuracy of different CFD approaches to simulate the mixing characteristics. Reynolds Averaged Navier Stokes (RANS) turbulence models are utilized to model all the cases as steady turbulence models. Moreover, unsteady turbulence models, such as Unsteady RANS, and Large Eddy Simulation (LES) are used to provide information about unsteady features in selected cases. The sensitivities of numerical predictions to different RANS turbulence models as well as to different turbulent Schmidt numbers are explored.
Publisher: LAP Lambert Academic Publishing
ISBN: 9783848486052
Category :
Languages : en
Pages : 176
Book Description
In the present work, mixing of hydrogen and methane into air is simulated using various CFD approaches. Fuel is injected either co-flowing to the air flow ( axial injection ) or perpendicular to the air flow ( radial injection ). The quality of the simulations is evaluated by comparing the numerical results with experimental measurements. Qualitative and quantitative comparisons are used to evaluate the relative accuracy of different CFD approaches to simulate the mixing characteristics. Reynolds Averaged Navier Stokes (RANS) turbulence models are utilized to model all the cases as steady turbulence models. Moreover, unsteady turbulence models, such as Unsteady RANS, and Large Eddy Simulation (LES) are used to provide information about unsteady features in selected cases. The sensitivities of numerical predictions to different RANS turbulence models as well as to different turbulent Schmidt numbers are explored.
Experimental Studies of Hydrogen-air Mixing Processes
Author: Scott P. Hill
Publisher:
ISBN: 9781124513669
Category :
Languages : en
Pages : 323
Book Description
Increasing concerns over pollutant emissions and fuel scarcity have led to increased interest into new fuel sources in general and hydrogen in particular. Hydrogen has the potential to be sourced as a renewable fuel with no net carbon emissions and low pollutant emissions. However, to achieve the low pollutant emissions, a thorough understanding of the fuel and its mixing properties are required. To aid in this understanding, this study focuses on the mixing processes of hydrogen and air. To accomplish this understanding, measurements of fuel concentration and velocity were obtained at a number of planes downstream of the fuel injection plane. Injection type and flow conditions were varied to evaluate their impact on the mixing, and measurements were obtained for both hydrogen and methane. The primary findings of the study suggest that for low pressure drop fuel injection the jet-momentum flux ratio is the controlling value for the injection mixing behavior, and that little to no discernable difference was found in the spatial distribution of hydrogen in comparison to methane. Additionally, it was found that the addition of flow swirl improved mixing near the injection plane, but that it created a reduced level of radial mixing further downstream as it worked to maintain a core of high fuel concentration. Overall, the results suggest that many of the standard design tools employed for more standard fuels such as methane still hold true for hydrogen, with the difference between the two being the larger volume of hydrogen due to its lower density.
Publisher:
ISBN: 9781124513669
Category :
Languages : en
Pages : 323
Book Description
Increasing concerns over pollutant emissions and fuel scarcity have led to increased interest into new fuel sources in general and hydrogen in particular. Hydrogen has the potential to be sourced as a renewable fuel with no net carbon emissions and low pollutant emissions. However, to achieve the low pollutant emissions, a thorough understanding of the fuel and its mixing properties are required. To aid in this understanding, this study focuses on the mixing processes of hydrogen and air. To accomplish this understanding, measurements of fuel concentration and velocity were obtained at a number of planes downstream of the fuel injection plane. Injection type and flow conditions were varied to evaluate their impact on the mixing, and measurements were obtained for both hydrogen and methane. The primary findings of the study suggest that for low pressure drop fuel injection the jet-momentum flux ratio is the controlling value for the injection mixing behavior, and that little to no discernable difference was found in the spatial distribution of hydrogen in comparison to methane. Additionally, it was found that the addition of flow swirl improved mixing near the injection plane, but that it created a reduced level of radial mixing further downstream as it worked to maintain a core of high fuel concentration. Overall, the results suggest that many of the standard design tools employed for more standard fuels such as methane still hold true for hydrogen, with the difference between the two being the larger volume of hydrogen due to its lower density.
International Aerospace Abstracts
Applied Mechanics Reviews
Dissertation Abstracts International
Author:
Publisher:
ISBN:
Category : Dissertations, Academic
Languages : en
Pages : 886
Book Description
Publisher:
ISBN:
Category : Dissertations, Academic
Languages : en
Pages : 886
Book Description
MILD Combustion: Modelling Challenges, Experimental Configurations and Diagnostic Tools
Author: Alessandro Parente
Publisher: Frontiers Media SA
ISBN: 2889717003
Category : Technology & Engineering
Languages : en
Pages : 160
Book Description
Publisher: Frontiers Media SA
ISBN: 2889717003
Category : Technology & Engineering
Languages : en
Pages : 160
Book Description
AN EXPERIMENTAL STUDY OF COAXIAL TURBULENT MIXING OF LIQUID AND GASEOUS FUEL WITH AIR
Flashback Mechanisms in Lean Premixed Gas Turbine Combustion
Author: Ali Cemal Benim
Publisher: Academic Press
ISBN: 0128008261
Category : Technology & Engineering
Languages : en
Pages : 134
Book Description
Blending fuels with hydrogen offers the potential to reduce NOx and CO2 emissions in gas turbines, but doing so introduces potential new problems such as flashback. Flashback can lead to thermal overload and destruction of hardware in the turbine engine, with potentially expensive consequences. The little research on flashback that is available is fragmented. Flashback Mechanisms in Lean Premixed Gas Turbine Combustion by Ali Cemal Benim will address not only the overall issue of the flashback phenomenon, but also the issue of fragmented and incomplete research. - Presents a coherent review of flame flashback (a classic problem in premixed combustion) and its connection with the growing trend of popularity of more-efficient hydrogen-blend fuels - Begins with a brief review of industrial gas turbine combustion technology - Covers current environmental and economic motivations for replacing natural gas with hydrogen-blend fuels
Publisher: Academic Press
ISBN: 0128008261
Category : Technology & Engineering
Languages : en
Pages : 134
Book Description
Blending fuels with hydrogen offers the potential to reduce NOx and CO2 emissions in gas turbines, but doing so introduces potential new problems such as flashback. Flashback can lead to thermal overload and destruction of hardware in the turbine engine, with potentially expensive consequences. The little research on flashback that is available is fragmented. Flashback Mechanisms in Lean Premixed Gas Turbine Combustion by Ali Cemal Benim will address not only the overall issue of the flashback phenomenon, but also the issue of fragmented and incomplete research. - Presents a coherent review of flame flashback (a classic problem in premixed combustion) and its connection with the growing trend of popularity of more-efficient hydrogen-blend fuels - Begins with a brief review of industrial gas turbine combustion technology - Covers current environmental and economic motivations for replacing natural gas with hydrogen-blend fuels
Turbulent Premixed Flames
Author: Nedunchezhian Swaminathan
Publisher: Cambridge University Press
ISBN: 1139498584
Category : Technology & Engineering
Languages : en
Pages : 447
Book Description
A work on turbulent premixed combustion is important because of increased concern about the environmental impact of combustion and the search for new combustion concepts and technologies. An improved understanding of lean fuel turbulent premixed flames must play a central role in the fundamental science of these new concepts. Lean premixed flames have the potential to offer ultra-low emission levels, but they are notoriously susceptible to combustion oscillations. Thus, sophisticated control measures are inevitably required. The editors' intent is to set out the modeling aspects in the field of turbulent premixed combustion. Good progress has been made on this topic, and this cohesive volume contains contributions from international experts on various subtopics of the lean premixed flame problem.
Publisher: Cambridge University Press
ISBN: 1139498584
Category : Technology & Engineering
Languages : en
Pages : 447
Book Description
A work on turbulent premixed combustion is important because of increased concern about the environmental impact of combustion and the search for new combustion concepts and technologies. An improved understanding of lean fuel turbulent premixed flames must play a central role in the fundamental science of these new concepts. Lean premixed flames have the potential to offer ultra-low emission levels, but they are notoriously susceptible to combustion oscillations. Thus, sophisticated control measures are inevitably required. The editors' intent is to set out the modeling aspects in the field of turbulent premixed combustion. Good progress has been made on this topic, and this cohesive volume contains contributions from international experts on various subtopics of the lean premixed flame problem.