Goss, LP
1994
Observations of Flame Behavior from a Practical Fuel Injector Using Gaseous Fuel in a Technolgoy Combustor
Hedman, P.O.; Sturgess, G.J.; Warren, D.L.; Goss, L.P. and Shouse, D.T.
Transactions of the ASME, 1994 (in press). (Also presented at the ASME International Gas Turbine and Aeroengine Congress and Exposition, The Hague, Netherlands, June 1994. Funded by ACERC, Wright Patterson Air Force Base and Air Force Office of Scientific Research.
This paper presents results from an Air Force program being conducted by researchers at Brigham Young University (BYU), Wright-Patterson Air Force Base (WPAFB), and Pratt and Whitney Aircraft Co. (P&W). This study is part of a comprehensive effort being supported by the Aero Propulsion and Power Laboratory at Wright-Patterson Air Force Base, and Pratt and Whitney, Inc. in which simple and complex diffusion flames are being studied to better understand the fundamentals of gas turbine combustion near lean blowout. The program's long-term goal is to improve the design methodology of gas turbine combustors.
This paper focuses on four areas of investigation: 1) digitized images from still film photographs to document the observed flame structures as fuel equivalence ratio was varied, 2) sets of LDA data to quantify the velocity flow fields existing in the burner, 3) CARS measurements of gas temperature to determine the temperature field in the combustion zone, and to evaluate the magnitude of peak temperature, and 4) two-dimensional images of OH radical concentrations using PLIF to document the instantaneous location of the flame reaction zones.
1992
Investigation of the Combustion Characteristics of a Swirled Injector in a Confined Coannular System with a Sudden Expansion
Warren, D.; Pyper, D.K.; Blackham, S.; Christensen, J.; Hedman, P.O.; Goss, L.P.; Trump, D.; Sarka, B.; Hsu, K.Y. and Roquemore, W.M.
Fall Meeting of the Western States Section/The Combustion Institute, Berkeley, CA, October 1992. Funded by Wright-Patterson Air Force Base and Air Force Office of Scientific Research.
This paper presents preliminary results of an Air Force Office of Scientific Research (AFOSR) program being conducted at Brigham Young University (BYU), Provo, Utah and at Wright-Patterson Air Force Base (WPAFB) under Summer Faculty and Research Initiation Programs. This study is part of an extensive research effort being carried out by the Fuels Combustion Group of the Aero Propulsion and Power Laboratory at Wright Patterson Air Force Base (APPL, WPAFB), Dayton, Ohio, in which simple and complex diffusion flames are being studied to better understand the fundamentals of gas turbine combustion. The program's long-term goal is to improve the design methodology of gas turbine combustors.
The work at BYU is being accomplished by the systematic study of a geometrically simple burner "designed and developed to specifically reproduce recirculation patterns and lean blow out (LBO) processes that occur in a real gas turbine combustor" (Sturgess, et al., 1990). There are two configurations used in the burner. The Task 100 burner uses a central fuel tube surrounded by a concentric air jet with a step expansion at the plane of discharge. The Task 150 burner has replaced the central fuel and air tubes with a double swirler injector from an actual Pratt-Whitney jet engine. Both configurations have been designed to be nearly axisymmetric and incorporate quartz windows to allow laser diagnostics. The burner is currently fueled by propane.
This paper contains a brief summary of work done at BYU and at Wright-Patterson Air Force base during the AFOSR summer faculty research programs. Intriguing flame structures have been visually characterized and captured in both still and video images with both the Task 100 and Task 150 configurations. Additional images of the flame and flow structures have been taken with laser sheet lighting, including Mie scattering and OH- florescence. These two-dimensional laser images have frozen structures missed with the visual observations due to the integrating nature of the eye and camera. LDA velocity maps have been collected over a variety of conditions, ranging from the relatively simple flow of the Task 150. This information not only yields velocity and turbulence data but will be used to obtain streamline functions as well. Both isothermal flow and combusting hot flow data have been collected. Limited CARS temperature data is compared in the paper LDA velocity maps and LIF image of OH-. Additional CARS temperature data are currently being collected at the test conditions of the LDA measurements and OH- images.
1991
Experimental and Theoretical Studies in a Gas-Fueled Research Combustor
Roquemore, W.M.; Reddy, V.K.; Hedman, P.O.; Post, M.E.; Chen, T.H.; Goss, L.P.; Trump, D.; Vilimpoc, V. and Sturgess, G.J.
AIAA 29th Aerospace Sciences Meeting, Reno, NV, January 1991. Funded by US Air Force.
This paper reports the results of an investigation to determine the flow and flame characteristics of a burner which has been carefully designed to "specifically reproduce recirculation patterns and lean-blow-out (LBO) processes that occur in a real gas turbine combustor." When operated in a fuel rich mode, the flame is very stable and is anchored in the jet shear layer by a pilot flame attached to the step, near the outer edge of the air supply tube. As the equilivalence ratio is reduced, the flame becomes less stable, and eventually reaches a point where the pilot flame becomes detached (lifts) from the base region, and the entire flame structure becomes stabilized downstream. Thus, there are two distinct operating modes for the combustor: a fully attached flame and a lifted flame. As the fuel equivalence ratio is further reduced, the flame becomes progressively less stable in its lifted condition, and eventually blows out. Photographs of the flame clearly illustrate the attached and lifted flame operational regimes of the combustor. However, visual observation and conventional photographic techniques are unable to quantify the precise details of the flame transition from an attached to a lifted condition. A Computational Fluid Dynamics (CFD) model with one step chemistry was used to investigate the time-averaged features of the reacting and non-reacting flow fields. The difficulties of predicting the characteristics of the attached flame with a time averaged CFD type model are discussed. Measurements, using OH emissions and gray body radiation from 14 µm diameter filaments located near the base of the flame, clearly indicate the dynamic or intermittent nature of both the attached and lifted flames. It is theorized that unburned hydrocarbon combustion products are transported into the recirculation zone by the intermittent process; and it is these products that provide the fuel needed for the flame to attach to the outer edge of the step.
Goss, LP
1994
Observations of Flame Behavior from a Practical Fuel Injector Using Gaseous Fuel in a Technolgoy Combustor
Hedman, P.O.; Sturgess, G.J.; Warren, D.L.; Goss, L.P. and Shouse, D.T.
Transactions of the ASME, 1994 (in press). (Also presented at the ASME International Gas Turbine and Aeroengine Congress and Exposition, The Hague, Netherlands, June 1994. Funded by ACERC, Wright Patterson Air Force Base and Air Force Office of Scientific Research.
This paper presents results from an Air Force program being conducted by researchers at Brigham Young University (BYU), Wright-Patterson Air Force Base (WPAFB), and Pratt and Whitney Aircraft Co. (P&W). This study is part of a comprehensive effort being supported by the Aero Propulsion and Power Laboratory at Wright-Patterson Air Force Base, and Pratt and Whitney, Inc. in which simple and complex diffusion flames are being studied to better understand the fundamentals of gas turbine combustion near lean blowout. The program's long-term goal is to improve the design methodology of gas turbine combustors.
This paper focuses on four areas of investigation: 1) digitized images from still film photographs to document the observed flame structures as fuel equivalence ratio was varied, 2) sets of LDA data to quantify the velocity flow fields existing in the burner, 3) CARS measurements of gas temperature to determine the temperature field in the combustion zone, and to evaluate the magnitude of peak temperature, and 4) two-dimensional images of OH radical concentrations using PLIF to document the instantaneous location of the flame reaction zones.
1992
Investigation of the Combustion Characteristics of a Swirled Injector in a Confined Coannular System with a Sudden Expansion
Warren, D.; Pyper, D.K.; Blackham, S.; Christensen, J.; Hedman, P.O.; Goss, L.P.; Trump, D.; Sarka, B.; Hsu, K.Y. and Roquemore, W.M.
Fall Meeting of the Western States Section/The Combustion Institute, Berkeley, CA, October 1992. Funded by Wright-Patterson Air Force Base and Air Force Office of Scientific Research.
This paper presents preliminary results of an Air Force Office of Scientific Research (AFOSR) program being conducted at Brigham Young University (BYU), Provo, Utah and at Wright-Patterson Air Force Base (WPAFB) under Summer Faculty and Research Initiation Programs. This study is part of an extensive research effort being carried out by the Fuels Combustion Group of the Aero Propulsion and Power Laboratory at Wright Patterson Air Force Base (APPL, WPAFB), Dayton, Ohio, in which simple and complex diffusion flames are being studied to better understand the fundamentals of gas turbine combustion. The program's long-term goal is to improve the design methodology of gas turbine combustors.
The work at BYU is being accomplished by the systematic study of a geometrically simple burner "designed and developed to specifically reproduce recirculation patterns and lean blow out (LBO) processes that occur in a real gas turbine combustor" (Sturgess, et al., 1990). There are two configurations used in the burner. The Task 100 burner uses a central fuel tube surrounded by a concentric air jet with a step expansion at the plane of discharge. The Task 150 burner has replaced the central fuel and air tubes with a double swirler injector from an actual Pratt-Whitney jet engine. Both configurations have been designed to be nearly axisymmetric and incorporate quartz windows to allow laser diagnostics. The burner is currently fueled by propane.
This paper contains a brief summary of work done at BYU and at Wright-Patterson Air Force base during the AFOSR summer faculty research programs. Intriguing flame structures have been visually characterized and captured in both still and video images with both the Task 100 and Task 150 configurations. Additional images of the flame and flow structures have been taken with laser sheet lighting, including Mie scattering and OH- florescence. These two-dimensional laser images have frozen structures missed with the visual observations due to the integrating nature of the eye and camera. LDA velocity maps have been collected over a variety of conditions, ranging from the relatively simple flow of the Task 150. This information not only yields velocity and turbulence data but will be used to obtain streamline functions as well. Both isothermal flow and combusting hot flow data have been collected. Limited CARS temperature data is compared in the paper LDA velocity maps and LIF image of OH-. Additional CARS temperature data are currently being collected at the test conditions of the LDA measurements and OH- images.
1991
Experimental and Theoretical Studies in a Gas-Fueled Research Combustor
Roquemore, W.M.; Reddy, V.K.; Hedman, P.O.; Post, M.E.; Chen, T.H.; Goss, L.P.; Trump, D.; Vilimpoc, V. and Sturgess, G.J.
AIAA 29th Aerospace Sciences Meeting, Reno, NV, January 1991. Funded by US Air Force.
This paper reports the results of an investigation to determine the flow and flame characteristics of a burner which has been carefully designed to "specifically reproduce recirculation patterns and lean-blow-out (LBO) processes that occur in a real gas turbine combustor." When operated in a fuel rich mode, the flame is very stable and is anchored in the jet shear layer by a pilot flame attached to the step, near the outer edge of the air supply tube. As the equilivalence ratio is reduced, the flame becomes less stable, and eventually reaches a point where the pilot flame becomes detached (lifts) from the base region, and the entire flame structure becomes stabilized downstream. Thus, there are two distinct operating modes for the combustor: a fully attached flame and a lifted flame. As the fuel equivalence ratio is further reduced, the flame becomes progressively less stable in its lifted condition, and eventually blows out. Photographs of the flame clearly illustrate the attached and lifted flame operational regimes of the combustor. However, visual observation and conventional photographic techniques are unable to quantify the precise details of the flame transition from an attached to a lifted condition. A Computational Fluid Dynamics (CFD) model with one step chemistry was used to investigate the time-averaged features of the reacting and non-reacting flow fields. The difficulties of predicting the characteristics of the attached flame with a time averaged CFD type model are discussed. Measurements, using OH emissions and gray body radiation from 14 µm diameter filaments located near the base of the flame, clearly indicate the dynamic or intermittent nature of both the attached and lifted flames. It is theorized that unburned hydrocarbon combustion products are transported into the recirculation zone by the intermittent process; and it is these products that provide the fuel needed for the flame to attach to the outer edge of the step.