Behavior of Unconfined Swirling Flames Under Fuel-Lean Conditions Using Particle Image Velocimetry

2006 ◽  
Author(s):  
S. S. Archer ◽  
A. K. Gupta
Keyword(s):  
Direct Injection ◽  
Air Flow ◽  
Model Development ◽  
Flow Characteristics ◽  
Swirl Flow ◽  
Flow Dynamics ◽  
Swirl Burner ◽  
Swirl Number ◽  
Outer Flow ◽  
Lean Direct Injection

The effect of swirl and combustion are presented to determine the flow dynamics of a fuel-lean direct injection (LDI) configuration under unconfined non-burning and combustion conditions. Specifically, the effect of radial distribution of combustion air swirl in a burner is examined under non-burning and burning conditions using propane as the fuel. The study explores the swirl flow interaction with the use of an experimental double concentric swirl burner that simulates one swirl cup of a practical gas turbine combustor. Three-dimensional (3-D) flowfield data has been obtained immediately downstream of a double concentric swirl burner exit using PIV, to determine the flow dynamics associated with the flow under fuel-lean direct injection (LDI) conditions. Propane fuel was injected radially into the surrounding swirl flow. Flow characteristics of the resulting flowfield, both without and with combustion have been obtained for co- and counter-swirl distributions to the combustion air flow under unconfined environment. Flat vane swirlers have been used to induce swirl to the air flow. Both combustion and swirl distribution significantly influences the resulting flowfield. The 3-D data also allows one to determine the local swirl number of the resulting flow. Results show that swirl distribution in the burner and combustion has significant effect on the characteristics of the internal and external recirculation zones. The heat release from combustion enhanced the inner recirculation zone by increasing its width and length. Combustion increased the magnitude of the vorticity and provided enhanced symmetry to the flowfields. The calculated local swirl number differs under non-burning and combustion cases. They also differ from that estimated using available geometrical relationships that are derived from the swirl vane angle and swirler dimensions only. Combustion enhanced significant increase in velocity magnitudes than that for the no combustion conditions. The entrained mass flowrate is larger for the co-swirl distribution cases and this entrainment is further enhanced with combustion. The results provide the role of radial swirl distribution and combustion on the mean and turbulence characteristics of flows for two varying shear conditions between the inner and outer flow of the burner, thus providing insightful information on the flow dynamics in complex swirl flowfields in addition to providing data for model validation and model development.

Confinement Effects on Flow Dynamics in Swirling Flames

2005 ◽  
Author(s):  
S. Archer ◽  
A. K. Gupta
Keyword(s):  
Gas Turbine ◽  
Recirculation Zone ◽  
Direct Injection ◽  
Model Development ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Flow Dynamics ◽  
Swirl Number ◽  
Outer Flow ◽  
Lean Direct Injection

Three-dimensional (3-D) flowfield data has been obtained using Particle Image Velocimetry (PIV) for varying swirl distributions in the burner. The 3-D data also allows one determine the local swirl number of the resulting flow. Flow characteristics of the resulting flowfield, both without and with combustion, have been examined for the effect of co- and counter-swirl under lean direct injection conditions using unconfined and confined combustor geometry. Experimental results of the effect of swirl and combustion are presented to simulate the flow dynamics of Lean Direct Injection (LDI) configuration gas turbine combustion. The selected configuration is typical because it does not make use a premixing zone and relies totally on the swirl and the injector to accomplish rapid mixing. Specifically, the effect of radial distribution of combustion air and swirl in a burner are examined under non-burning and burning conditions using propane as the fuel. The present study explores single swirler interaction with the use of an experimental double concentric swirl burner that simulates one swirler of a practical gas turbine combustor. Results showed that both swirl and combustion has significant effect on the characteristics of the internal and external recirculation zones. The calculated local swirl number differs significantly form that estimated using geometrical relationship derived from the vane angle only. The effect of combustion for the confined and unconfined geometries was also been found to be different. In the confined geometry combustion decreases the size of the recirculation zone. This is in contrast to that found for the unconfined conditions. Combustion enhances the recirculation zone in the unconfined geometry. Combustion provides greater velocity magnitudes than their counter non-combustion conditions. The counter-swirl combination resulted in smaller and more well defined internal recirculation regions. The results provide the role of swirl and combustion on the mean and turbulence characteristics of flows over a range of swirl and shear conditions between the inner and outer flow of the burner. This data provides important insights on the flow dynamics in addition to providing data for model validation and model development.

Flow Dynamics of Unconfined and Confined Swirl Stabilized Gaseous Flames

2004 ◽  
Author(s):  
S. Archer ◽  
A. K. Gupta
Keyword(s):  
Gas Turbine ◽  
Recirculation Zone ◽  
Direct Injection ◽  
Model Development ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Flow Dynamics ◽  
Swirl Number ◽  
Outer Flow ◽  
Lean Direct Injection

Three-dimensional (3-D) flowfield data has been obtained using Particle Image Velocimetry (PIV) for varying swirl distributions in the burner. The 3-D data also allows one determine the local swirl number of the resulting flow. Flow characteristics of the resulting flowfield, both without and with combustion, have been examined for the effect of co- and counter-swirl under lean direct injection conditions using unconfined and confined combustor geometry. Experimental results of the effect of swirl and combustion are presented to simulate the flow dynamics of Lean Direct Injection (LDI) configuration gas turbine combustion. The selected configuration is typical because it does not make use a premixing zone and relies totally on the swirl and the injector to accomplish rapid mixing. Specifically, the effect of radial distribution of combustion air and swirl in a burner are examined under non-burning and burning conditions using propane as the fuel. The present study explores single swirler interaction with the use of an experimental double concentric swirl burner that simulates one swirler of a practical gas turbine combustor. Results showed that both swirl and combustion has significant effect on the characteristics of the internal and external recirculation zones. The calculated local swirl number differs significantly form that estimated using geometrical relationship derived from the vane angle only. The effect of combustion for the confined and unconfined geometries was also been found to be different. In the confined geometry combustion decreases the size of the recirculation zone. This is in contrast to that found for the unconfined conditions. Combustion enhances the recirculation zone in the unconfined geometry. Combustion provides greater velocity magnitudes than their counter non-combustion conditions. The counter-swirl combination resulted in smaller and more well defined internal recirculation regions. The results provide the role of swirl and combustion on the mean and turbulence characteristics of flows over a range of swirl and shear conditions between the inner and outer flow of the burner. This data provides important insights on the flow dynamics in addition to providing data for model validation and model development.

Confinement Effects on Flow and Combustion Under Fuel Lean Conditions

2004 ◽  
Author(s):  
S. Archer ◽  
A. K. Gupta
Keyword(s):  
Gas Turbine ◽  
Recirculation Zone ◽  
Direct Injection ◽  
Model Development ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Flow Dynamics ◽  
Swirl Number ◽  
Outer Flow ◽  
Lean Direct Injection

Three-dimensional (3-D) flowfield data has been obtained using Particle Image Velocimetry (PIV) for varying swirl distributions in the burner. The 3-D data also allows one determine the local swirl number of the resulting flow. Flow characteristics of the resulting flowfield, both without and with combustion, have been examined for the effect of co- and counter-swirl under lean direct injection conditions using unconfined and confined combustor geometry. Experimental results of the effect of swirl and combustion are presented to simulate the flow dynamics of Lean Direct Injection (LDI) configuration gas turbine combustion. The selected configuration is typical because it does not make use a premixing zone and relies totally on the swirl and the injector to accomplish rapid mixing. Specifically, the effect of radial distribution of combustion air and swirl in a burner are examined under non-burning and burning conditions using propane as the fuel. The present study explores single swirler interaction with the use of an experimental double concentric swirl burner that simulates one swirler of a practical gas turbine combustor. Results showed that both swirl and combustion has significant effect on the characteristics of the internal and external recirculation zones. The calculated local swirl number differs significantly form that estimated using geometrical relationship derived from the vane angle only. The effect of combustion for the confined and unconfined geometries was also been found to be different. In the confined geometry combustion decreases the size of the recirculation zone. This is in contrast to that found for the unconfined conditions. Combustion enhances the recirculation zone in the unconfined geometry. Combustion provides greater velocity magnitudes than their counter non-combustion conditions. The counter-swirl combination resulted in smaller and more well defined internal recirculation regions. The results provide the role of swirl and combustion on the mean and turbulence characteristics of flows over a range of swirl and shear conditions between the inner and outer flow of the burner. This data provides important insights on the flow dynamics in addition to providing data for model validation and model development.

Flow Dynamics Under Confined and Unconfined Combustion Conditions

2004 ◽  
Author(s):  
S. Archer ◽  
A. K. Gupta
Keyword(s):  
Spatial Distribution ◽  
Gas Turbine ◽  
Recirculation Zone ◽  
Direct Injection ◽  
Model Development ◽  
Flow Dynamics ◽  
Swirl Number ◽  
Iccd Camera ◽  
Outer Flow ◽  
Lean Direct Injection

Three-dimensional (3-D) flowfield data has been obtained using Particle Image Velocimetry (PIV). Information on selected intermediate flame generated species that mark the flame front and heat release rate has been obtained using optical emission spectroscopy (OES). Instantaneous images on the spatial distribution of OH, CH, and C2 species from within the flames have been obtained using an ICCD camera and narrow band interference filters. The instantaneous images are then integrated to obtain time-averaged information. The PIV and OES diagnostics are employed for varying swirl distributions in the burner. The 3-D data also allows one determine the local swirl number of the resulting flow. Flow characteristics of the resulting flowfield, both without and with combustion, have been examined for the effect of co- and counter-swirl under lean direct injection conditions using unconfined and confined combustor geometry. The OES diagnostics provides information on the spatial distribution of desired species as affected by flame confinement and swirl distribution in flames. Experimental results of the effect of swirl and combustion are presented to simulate the flow dynamics of Lean Direct Injection (LDI) configuration gas turbine combustion. The selected configuration is typical because it does not make use a premixing zone and relies totally on the swirl and the injector to accomplish rapid mixing. Specifically, the effect of radial distribution of combustion air and swirl in a burner are examined under non-burning and burning conditions using propane as the fuel. The present study explores single swirler interaction with the use of an experimental double concentric swirl burner that simulates one swirler of a practical gas turbine combustor. Results showed that both swirl and combustion has significant effect on the characteristics of the internal and external recirculation zones. The calculated local swirl number differs significantly form that estimated using geometrical relationship derived from the vane angle only. The effect of combustion for the confined and unconfined geometries has also been found to be different. In the confined geometry combustion decreases the size of the recirculation zone. This is in contrast to that found for the unconfined conditions. Combustion enhances the recirculation zone in the unconfined geometry. Combustion provides greater velocity magnitudes than their counter noncombustion conditions. The counter-swirl combination resulted in smaller and better defined internal recirculation regions. OES results showed that swirl distribution affects the shape of the spatial distribution by spreading the high intensity regions radially outwards with the co-swirl configuration. Confinement increased the intensity and spatial distribution of the investigated species. The results provide the role of swirl, combustion and flame confinement on the mean and turbulence characteristics of flows over a range of swirl and shear conditions between the inner and outer flow of the burner. The results also provide important role on the flow and chemical behavior. This data provides important insights on the flow dynamics in addition to providing data for model validation and model development.

Swirl and Combustion Effects on Flow Dynamics in Lean Direct Injection Gas Turbine Combustion

2003 ◽  
Author(s):  
S. Archer ◽  
A. K. Gupta
Keyword(s):  
Gas Turbine ◽  
Direct Injection ◽  
Model Development ◽  
Flow Characteristics ◽  
Flow Dynamics ◽  
Outer Flow ◽  
Lean Direct Injection ◽  
Image Velocimetry ◽  
Recirculation Zones ◽  
Gas Turbine Combustion

The effect of swirl and combustion are presented for a Lean Direct Injection (LDI) configuration in gas turbine combustion. Specifically, the effect of radial distribution of combustion air and swirl in a burner are examined under nonburning and burning conditions using propane as the fuel. The present study explores single swirler interaction with the use of an experimental double concentric swirl burner that simulates one swirler of a practical gas turbine combustor. Flowfield data has been obtained using Particle Image Velocimetry (PIV) for varying swirl distributions. The flow characteristics of the resulting flowfields have been examined under lean direct injection (LDI) conditions. The affects of coand counter-swirl have also been carried out. Results showed that both swirl and combustion has significant effect on the characteristics of the internal and external recirculation zones. Combustion provides greater axial velocities than their counter non-combustion conditions. The counter-swirl combination resulted in smaller and more well defined internal recirculation regions. The results provide the role of swirl and combustion on the mean and turbulence characteristics of flows over a range of swirl and shear conditions between the inner and outer flow of the burner. This data provides important insights on the flow dynamics in addition to providing data for model validation and model development.

Flow Dynamics of Unconfined Swirling Flames Under Fuel-Lean Conditions

2006 ◽  
Author(s):  
S. S. Archer ◽  
A. K. Gupta ◽  
K. Kitagawa
Keyword(s):  
Direct Injection ◽  
Air Flow ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Swirl Flow ◽  
Flow Dynamics ◽  
Swirl Number ◽  
Burner Exit ◽  
Swirl Vane

This study provides the role of co- and counter swirl distribution in a experimental double concentric swirl burner that simulates the that simulates one swirl cup of a practical gas turbine combustor. Results of the effect of radial distribution of swirl in a burner under unconfined non-burning and combustion conditions are presented on the flow dynamics of a fuel-lean direct injection (LDI) configuration using propane as the fuel. Three-dimensional (3-D) flowfield data has been obtained immediately downstream of the burner exit to determine the detailed flow dynamics associated with the flow. The fuel was injected radially into the surrounding swirl flow. Flow characteristics, both without and with combustion, have been obtained for the co- and counter-swirl distributions to the combustion air flow under unconfined conditions. Flat vane swirlers have been used to induce swirl to the air flow. Both combustion and swirl distribution significantly influences the resulting flowfield. The resulting swirl number of the flow was calculated using the 3-D velocity data. Results show that swirl distribution in the burner and combustion provides significant effect on the characteristics of the internal and external recirculation zones. The heat release from combustion enhances the inner recirculation zone by increasing its width and length. Combustion causes significant increase to the velocity and vorticity magnitudes in the flow, and promotes flowfield symmetry. Combustion also affects the swirl number of the flow. The swirl number calculated from the geometrical relationships, derived from the swirl vane angle and swirler dimensions, is much different than that determined from the 3-D velocity field data. The entrained mass flow rate is larger for the co-swirl distribution case and this entrainment is further enhanced with combustion. The results provide the role of radial swirl distribution on the mean and turbulence characteristics of flows for the two different shear flow conditions between the inner and outer annulus of the burner.

Flow Field of a Model Gas Turbine Swirl Burner

2012 ◽  
Vol 622-623 ◽  
pp. 1119-1124 ◽  
Author(s):  
Cheng Tung Chong ◽  
Simone Hochgreb
Keyword(s):  
Flow Field ◽  
Radial Velocity ◽  
Gas Turbine ◽  
Air Flow ◽  
Atmospheric Condition ◽  
Flow Fields ◽  
Swirl Flow ◽  
Scale Model ◽  
Swirl Burner ◽  
Swirling Air Flow

The flow field of a lab-scale model gas turbine swirl burner was characterised using particle imaging velocimetry (PIV) at atmospheric condition. The swirl burner consists of an axial swirler, a twin-fluid atomizer and a quartz tube as combustor wall. The main non-reacting swirling air flow without spray was compared to swirl flow with spray under unconfined and enclosed conditions. The introduction of liquid fuel spray changes the flow field of the main swirling air flow at the burner outlet where the radial velocity components are enhanced. Under reacting conditions, the enclosure generates a corner recirculation zone that intensifies the strength of the radial velocity. Comparison of the flow fields with a spray flame using diesel and palm biodiesel shows very similar flow fields. The flow field data can be used as validation target for swirl flame modelling.

Study of Swirling Air Flow Characteristics in a Lean Direct Injection Combustor

2010 ◽  
Author(s):  
Dipanjay Dewanji ◽  
Arvind G. Rao ◽  
Mathieu Pourquie ◽  
Jos P. van Buijtenen
Keyword(s):  
Numerical Model ◽  
Flow Field ◽  
Swirling Flow ◽  
Direct Injection ◽  
Flow Characteristics ◽  
Single Element ◽  
Complex Flow ◽  
Flow Passage ◽  
Lean Direct Injection ◽  
Entire Flow

This paper investigates the non-reacting aerodynamic flow characteristics in Lean Direct Injection (LDI) combustors. The RANS modeling is used to simulate the turbulent, non-reacting, and confined flow field associated with a single-element and a nine-element LDI combustor. The results obtained from the simulation are compared with some experimental data available in literature. The numerical model, which is in accordance with an experimental combustor, consists of an air swirler with 6 helical axial vanes of 60 degree vane angle and a converging-diverging duct, extending in a square flame tube. The numerical model covers the entire flow passage, including the highly swirling flow passage through the swirler vanes, and the combustion chamber. Simulation has been performed with a low Reynolds number realizable k-ε model and a Reynolds stress turbulence model. It is observed that the computational model is able to predict the central re-circulation zones (CTRZ), the corner recirculation zones, and the complex flow field associated with the adjacent swirlers with reasonable accuracy. The computed velocity components for the single-element case show that the flow field is similar to the experimental observations.

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