Effects of Effusion Cooling Pattern Near the Dilution Hole for a Double-Walled Combustor Liner: Part 1 — Overall Effectiveness Measurements

Shrager, Adam C.; Thole, Karen A.; Mongillo, Dominic

doi:10.1115/gt2018-77288

“…Also shown in Figure 10, the centerline effectiveness for each case was the same after x/D = 1 for ID = 11, which corresponds to the similarity in downstream flow fields for each case at ID = 11 shown in Figures 9c, 9f, and 9i. In addition, the flowfields of the current study correspond with the companion study [1], which found no significant change in effectiveness between the ID = 30 and 20 cases for the closed and inward geometries and a small decrease in effectiveness between the ID = 30 and 20 cases for the outward geometry.…”

Section: Effects Of the Effusion Hole Patternsupporting

confidence: 70%

“…The geometry was repeated so that there were 15 dilution holes to span the entire width of the wind tunnel and to ensure periodicity. The same panel geometry was presented in a companion paper [1] and was originally modeled after a singlewalled effusion liner with dilution holes presented by Scrittore [8]. Flow from the supply plenum traveled through the impingement holes, which then fed the effusion holes.…”

Section: Experimental Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Effects of Effusion Cooling Pattern Near the Dilution Hole for a Double-Walled Combustor Liner: Part 2 — Flowfield Measurements

Shrager

¹

,

Thole

²

,

Mongillo

³

2018

Volume 5C: Heat Transfer

Self Cite

0

View full text Add to dashboard Cite

The complex flowfield inside a gas turbine combustor creates a difficult challenge in cooling the combustor walls. Many modern combustors are designed with a double-wall that contain both impingement cooling on the backside of the wall and effusion cooling on the external side of the wall. Complicating matters is the fact that these double-walls also contain large dilution holes whereby the cooling film from the effusion holes is interrupted by the high-momentum dilution jets. Given the importance of cooling the entire panel, including the metal surrounding the dilution holes, the focus of this paper is understanding the flow in the region near the dilution holes. Near-wall flowfield measurements are presented for three different effusion cooling hole patterns near the dilution hole. The effusion cooling hole patterns were varied in the region near the dilution hole and include: no effusion holes; effusion holes pointed radially outward from the dilution hole; and effusion holes pointed radially inward toward the dilution hole. Particle image velocimetry (PIV) was used to capture the time-averaged flowfield at approaching freestream turbulence intensities of 0.5% and 13%. Results showed evidence of downward motion at the leading edge of the dilution hole for all three effusion hole patterns. In comparing the three geometries, the outward effusion holes showed significantly higher velocities toward the leading edge of the dilution jet relative to the other two geometries. Although the flowfield generated by the dilution jet dominated the flow downstream, each cooling hole pattern interacted with the flowfield uniquely. Approaching freestream turbulence did not have a significant effect on the flowfield.

show abstract

“…Flowfield measurements of a combustor liner were made in in a low speed, closed-loop wind tunnel. The combustor simulator used in this study is the same as described in a companion paper [1] and is a modification of the combustor simulator previously described by Vakil and Thole [12] and Scrittore et al [14]. The flow is driven by an axial fan and sent through a mainstream and secondary path.…”

Section: Experimental Methodsmentioning

confidence: 99%

“…The results provide a unique understanding of how different effusion cooling patterns interact with the dilution jet for a realistic combustor geometry. In addition, this paper will also provide a brief discussion on how the flowfields relate to the surface cooling measurements, which were presented in a companion paper [1].…”

Section: Introductionmentioning

confidence: 99%

Effects of Effusion Cooling Pattern Near the Dilution Hole for a Double-Walled Combustor Liner—Part II: Flowfield Measurements

Shrager

¹

,

Thole

²

,

Mongillo

³

2018

Journal of Engineering for Gas Turbines and Power

Self Cite

View full text Add to dashboard Cite

The complex flowfield inside a gas turbine combustor creates a difficult challenge in cooling the combustor walls. Many modern combustors are designed with a double-wall that contain both impingement cooling on the backside of the wall and effusion cooling on the external side of the wall. Complicating matters is the fact that these double-walls also contain large dilution holes whereby the cooling film from the effusion holes is interrupted by the high-momentum dilution jets. Given the importance of cooling the entire panel, including the metal surrounding the dilution holes, the focus of this paper is understanding the flow in the region near the dilution holes. Near-wall flowfield measurements are presented for three different effusion cooling hole patterns near the dilution hole. The effusion cooling hole patterns were varied in the region near the dilution hole and include: no effusion holes; effusion holes pointed radially outward from the dilution hole; and effusion holes pointed radially inward toward the dilution hole. Particle image velocimetry (PIV) was used to capture the time-averaged flowfield at approaching freestream turbulence intensities of 0.5% and 13%. Results showed evidence of downward motion at the leading edge of the dilution hole for all three effusion hole patterns. In comparing the three geometries, the outward effusion holes showed significantly higher velocities toward the leading edge of the dilution jet relative to the other two geometries. Although the flowfield generated by the dilution jet dominated the flow downstream, each cooling hole pattern interacted with the flowfield uniquely. Approaching freestream turbulence did not have a significant effect on the flowfield.

show abstract

Application of Planar Laser Rayleigh Scattering for Measurement of Gas Temperature Distributions in Effusion Jet Cooled Panels Exposed to High Temperatures

Grasso

¹

,

Snyder

²

,

Cetegen

³

2021

Journal of Heat Transfer

0

View full text Add to dashboard Cite

This experimental study examines the use of planar laser Rayleigh scattering to measure instantaneous gas temperature distributions at different heights above the surface of an effusion cooled plate. An experimental test rig was used to model combustor conditions with a bulk crossflow temperature of 1500 K. Carbon dioxide was used as coolant at multiple blowing ratios ranging from 1.12 to 11.1. A "temperature-pegging" methodology was used to process Rayleigh light scattering images to create high resolution and accurate temperature images at heights of 2, 2.75, and 3.5 mm above the surface of a prototypical effusion plate. Measured temperature distributions were used to calculate root mean square (RMS) distributions, and were also converted to film effectiveness maps based on the upstream crossflow gas and effusion coolant temperatures. It is found that film cooling region spreads upstream with increasing effusion jet blowing ratio parameter. The root mean square (RMS) deviation of gas temperatures over each measurement plane show that the RMS fluctuations are low inside and outside the effusion film, but are high near the film edge. At a given height above the effusion panel, the RMS fluctuations decrease in the film region with increasing blowing ratio. Film effectiveness follows similar trends with high film effectiveness region expanding with increasing effusion jet blowing ratios.

show abstract

Effects of Effusion Cooling Pattern Near the Dilution Hole for a Double-Walled Combustor Liner: Part 1 — Overall Effectiveness Measurements

Cited by 4 publications

References 18 publications

Effects of Effusion Cooling Pattern Near the Dilution Hole for a Double-Walled Combustor Liner: Part 2 — Flowfield Measurements

Effects of Effusion Cooling Pattern Near the Dilution Hole for a Double-Walled Combustor Liner: Part 2 — Flowfield Measurements

Effects of Effusion Cooling Pattern Near the Dilution Hole for a Double-Walled Combustor Liner—Part II: Flowfield Measurements

Application of Planar Laser Rayleigh Scattering for Measurement of Gas Temperature Distributions in Effusion Jet Cooled Panels Exposed to High Temperatures

Contact Info

Product

Resources

About