Partial Premixing Effects on the Reacting Jet of a High Pressure Axially Staged Combustor

2020 ◽  
Author(s):  
Tommy Genova ◽  
Michelle Otero ◽  
Jonathan Reyes ◽  
Kareem Ahmed ◽  
Scott Martin
Keyword(s):  
Gas Turbine ◽  
Particle Image ◽  
Recirculation Region ◽  
The Core ◽  
Jet In Crossflow ◽  
Image Velocimetry ◽  
Flow Field Characteristics ◽  
Partial Premixing ◽  
Coaxial Injector ◽  
Flame Behavior

Abstract The effects of partial premixing on a reacting jet-in-crossflow is investigated in a five atmosphere axially staged combustor at stationary gas turbine relevant conditions. The facility consists of a dump style headend burner that provides a crossflow with a quasi-uniform velocity and temperature profile to the axial stage to isolate the effects of the jet-in-crossflow. The headend burner is run with methane and air at a lean equivalence ratio to match industry emissions standards. For the current work,, the total air to the headend and axial stage is kept constant, and fuel is split between the headend and axial stage to represent different gas turbine loading conditions. For the cases analyzed, the fuel split to the axial stage went up to 25%. The axial stage consists of an optically accessible test section with a coaxial injector that provides variability to how long the methane and air can mix before entering the facility. Three different premixed levels are studied: fully premixed, non-premixed, and partially premixed. The flow-field characteristics of the reacting jet-in-crossflow are analyzed using particle image velocimetry (PIV), and flame behavior is quantified by employing CH* chemiluminescence. NO measurements are made at the exit of the facility using a Horiba emissions analyzer. Two different flames are observed: flames that burn in the leeward recirculation region and flames that burn at the core of the jet.

Partial Premixing Effects On the Reacting Jet of a High-Pressure Axially Staged Combustor

2021 ◽  
Author(s):  
Tommy Genova ◽  
Michelle Otero ◽  
Jonathan Reyes ◽  
Scott Martin ◽  
Kareem Ahmed
Keyword(s):  
Gas Turbine ◽  
Particle Image ◽  
Recirculation Region ◽  
The Core ◽  
Jet In Crossflow ◽  
Image Velocimetry ◽  
Flow Field Characteristics ◽  
Partial Premixing ◽  
Coaxial Injector ◽  
Flame Behavior

Abstract The effects of partial premixing on a reacting jet-in-crossflow is investigated in a five atmosphere axially staged combustor at stationary gas turbine relevant conditions. The facility consists of a dump style headend burner that provides a crossflow with a quasi-uniform velocity and temperature profile to the axial stage to isolate the effects of the jet-in-crossflow. The headend burner is run with methane and air at a lean equivalence ratio to match industry emissions standards. For the current work, the total air to the headend and axial stage is kept constant, and fuel is split between the headend and axial stage to represent different gas turbine loading conditions. For the cases analyzed, the fuel split to the axial stage went up to 25%. The axial stage consists of an optically accessible test section with a coaxial injector that provides variability to how long the methane and air can mix before entering the facility. Three different premixed levels are studied: fully premixed, non-premixed, and partially premixed. The flow-field characteristics of the reacting jet-in-crossflow are analyzed using particle image velocimetry (PIV), and flame behavior is quantified by employing CH* chemiluminescence. NO measurements are made at the exit of the facility using a Horiba emissions analyzer. Two different flames are observed: flames that burn in the leeward recirculation region and flames that burn at the core of the jet.

The Influence of Pressure on Flame-Flow Characteristics of a Reacting Jet in Crossflow

2021 ◽  
pp. 1-30
Author(s):  
Michelle Otero ◽  
Tommy Genova ◽  
Bernhard Stiehl ◽  
Anthony Morales ◽  
Scott Martin ◽  
...  
Keyword(s):  
Ignition Delay Time ◽  
Particle Image ◽  
Flow Characteristics ◽  
Elevated Pressure ◽  
Jet In Crossflow ◽  
Air Jet ◽  
Jet Trajectory ◽  
Image Velocimetry ◽  
Lift Off ◽  
Flame Behavior

Abstract This work experimentally investigates the effects of elevated combustor pressures on the characteristics of a lean premixed reacting methane/air jet injected into a lean vitiated crossflow using a 12.7mm axial jet. Experiments were conducted in an axially staged combustor, which implements a reacting jet in crossflow (RJIC) configuration and operates over a pressure range of 1 to 5 atmospheres. Simultaneous CH* chemiluminescence and Particle Image Velocimetry (PIV) are used to study the flow field and flame behavior. The results show that the reacting jet trajectory exhibits greater penetration with elevated pressure, which is a novel finding compared to available data in the literature. However, the flame lift-off point and ignition delay time both decreased with elevated pressure, which was attributed to decreased vorticity along the flame boundary which corresponds to increased Damköhler numbers (Da). Emissions measurements confirm the NOx increase with pressure as reported in the literature for single stage gas turbine combustors. Concurrently, emission measurements for the staged configuration show the strong NOx benefit of the RJIC system: the data proves a reduction of global outlet emission levels at elevated pressure with the axially staged configuration. The axial emission reduction was attributed to the decreasing lift-off at elevated pressure levels. Hence, the research emphasizes that the flame and emission characteristics are coupled; they are not only dependent on the geometric parameters and momentum flux ratios but are also a function of pressure.

scholarly journals Hydrodynamic Interactions between Bracket and Propeller of Podded Propulsor Based on Particle Image Velocimetry Test

Water ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1142
Author(s):  
Dagang Zhao ◽  
Chunyu Guo ◽  
Tiecheng Wu ◽  
Wei Wang ◽  
Xunbin Yin
Keyword(s):  
Particle Image Velocimetry ◽  
Flow Field ◽  
Working Conditions ◽  
Cross Sections ◽  
Particle Image ◽  
Podded Propulsor ◽  
Image Velocimetry ◽  
Theoretical Significance ◽  
Practical Engineering ◽  
Flow Field Characteristics

In this study, particle image velocimetry was used to measure the fine flow-field characteristics of an L-type podded propulsor in various working conditions. The flow-field details at different cross-sections between the propeller and the inclined bracket were compared and analyzed, allowing for more intuitive comparison of the flow-field characteristics of L-type podded propulsors. The interference mechanisms among the propeller, pod, and bracket of the L-type podded propulsors at different advance coefficients, deflection angles, and deflection directions were investigated in depth. The results of this study can serve as reference material and provide technical support for the design and practical shipbuilding application of L-type podded propulsors. Therefore, the results have theoretical significance and practical engineering value.

An Experimental Study on the Performance of Drag-Reducing Polymers in Single- and Multiphase Horizontal Flow Using Particle Image Velocimetry

2018 ◽  
Vol 140 (5) ◽  
Author(s):  
Ihab H. Alsurakji ◽  
A. Al-Sarkhi ◽  
M. Habib ◽  
Hassan M. Badr
Keyword(s):  
Particle Image Velocimetry ◽  
Particle Image ◽  
Pipe Wall ◽  
Fluid Dynamic ◽  
Water Soluble ◽  
Experimental Investigations ◽  
Two Phase ◽  
Image Velocimetry ◽  
Flow Field Characteristics ◽  
Phase Water

This paper presents experimental investigations conducted to understand the influence of water-soluble drag-reducing polymers (DRPs) in single- and two-phase (stratified wavy) flow on flow-field characteristics. These experiments have been presented for water and air–water flowing in a horizontal polyvinyl chloride 22.5-mm ID, 8.33-m long pipe. The effects of liquid flow rates and DRP concentrations on streamlines and the instantaneous velocity were investigated by using particle image velocimetry (PIV) technique. A comparison of the PIV results was performed by comparing them with the computational results obtained by fluent software. One of the comparisons has been done between the PIV results, where a turbulent flow with DRP was examined, and the laminar–computational fluid dynamic (CFD) prediction. An agreement was found in the region near the pipe wall in some cases. The results showed the powerfulness of using the PIV techniques in understanding the mechanism of DRP in single- and two-phase flow especially at the regions near the pipe wall and near the phases interface. The results of this study indicate that an increase in DRP concentrations results in an increase in drag reduction up to 45% in single-phase water flow and up to 42% in air–water stratified flow.

Velocity and Pressure Measurements Along a Row of Confined Cylinders

2007 ◽  
Vol 129 (10) ◽  
pp. 1314-1327 ◽  
Author(s):  
Barton L. Smith ◽  
Jack J. Stepan ◽  
Donald M. McEligot
Keyword(s):  
Reynolds Number ◽  
Particle Image Velocimetry ◽  
Particle Image ◽  
Flow Behavior ◽  
Symmetry Plane ◽  
Recirculation Region ◽  
Wide Angle ◽  
Pressure Measurements ◽  
Image Velocimetry ◽  
Flow Experiments

The results of flow experiments performed in a row of confined cylinders designed to mimic a model of a prismatic gas-cooled reactor lower plenum design are presented. Pressure measurements between the cylinders were made. Additionally, the flow field was measured using particle image velocimetry at two different resolutions (one at high resolution and a second with wide angle that includes three cylinders). Based on these measurements, five regimes of flow behavior are identified that are found to depend on Reynolds number. It is found that the recirculation region behind the cylinders is shorter than that of half-cylinders placed on the wall representing the symmetry plane. Unlike a single cylinder, the separation point is always found to be on the rear of the cylinders, even at very low Reynolds number.

Flow Structures behind Cylinders of Different Diameters Arranged Side-by-Side at Small Gap Ratios

2014 ◽  
Vol 348 ◽  
pp. 171-178
Author(s):  
Cheng Hsiung Kuo ◽  
Sen Yun Tseng ◽  
Sun Wen Hsu
Keyword(s):  
Particle Image Velocimetry ◽  
Particle Image ◽  
Recirculation Region ◽  
Flow Structures ◽  
Passive Flow Control ◽  
Passive Flow ◽  
Gap Ratio ◽  
Image Velocimetry ◽  
Large Cylinder ◽  
Different Diameters

The flow structures and their interactions behind side-by-side cylinders of unequal diameters at small gap ratios are studied by dye-flow visualization and particle image velocimetry at Reynolds number 1000. The whole-field mean and fluctuating velocity distributions and evolutions in the wakes are studied by the particle image velocimetry. As the gap ratio decreases, the mutual interaction of the wakes behind side-by-side cylinders pushes the recirculation region behind the large cylinder farther downstream at the expense of deterioration of the wake behind small cylinder. This change is important and may be relevant to the applications of passive flow control strategy.

Using CFD to Improve Aero-Engine Air/Oil Separator Design

2002 ◽  
Author(s):  
Carol Eastwick ◽  
Stephen Hibberd ◽  
Kathy Simmons ◽  
Yi Wang ◽  
Ian Care ◽  
...  
Keyword(s):  
Experimental Data ◽  
Particle Image Velocimetry ◽  
Gas Turbine ◽  
Particle Image ◽  
Environmental Concern ◽  
Labyrinth Seals ◽  
Two Phase ◽  
Turbine Engine ◽  
Image Velocimetry ◽  
Aero Engine

Within the transmission system of a commercial gas turbine engine the lubrication and cooling of shaft bearings is performed by oil injected into bearing chambers that are typically sealed with air-pressurised labyrinth seals. The subsequent air/oil mixture is scavenged from the bearing chamber with the oil being re-used, whilst the air is discharged overboard via an air/oil separator. Efficiency of separators is becoming a high priority to industry, with any loss of oil an environmental concern. To help improve the design of separators a computational model was created of an existing design and coupled two-phase CFD calculations were performed. A limited amount of experimental data, collected by particle image velocimetry (PIV) was available for validation.

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