Loading...
Please wait, while we are loading the content...
Similar Documents
Gt 2018-77290 Effects of Effusion Cooling Pattern near the Dilution Hole for a Double-walled Combustor Liner — Part 2 : Flowfield Measurements
| Content Provider | Semantic Scholar |
|---|---|
| Author | Shrager, Adam C. Thole, Karen A. |
| Copyright Year | 2018 |
| Abstract | 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. NOMENCLATURE b turbulence grid bar diameter d effusion hole diameter D dilution hole diameter DR density ratio of coolant to mainstream, ρc/ρ∞ H distance between impingement and effusion plates I momentum flux ratio, ρcUc/ ρ∞U∞ l characteristic length L length of effusion hole M blowing ratio, ρcUc/ ρ∞U∞ Rein inlet Reynolds number, U∞l/ Sp,d pitchwise spacing of effusion holes Ss,d spanwise spacing of effusion holes t thickness of effusion and impingement plates T temperature TL turbulence level, √(u′2 + w′)/2/U∞ Tu freestream turbulence intensity, √(u′∞ 2 +w′∞ 2 )/2/U∞ u,w xand z-velocities U∞ mainstream velocity VR velocity ratio, Uc/U∞ x,y,z position measured from origin at the center of the dilution hole |
| File Format | PDF HTM / HTML |
| DOI | 10.1115/gt2018-77290 |
| Alternate Webpage(s) | https://www.mne.psu.edu/turbine/Pubs/2018-Shrager-TE-Pt2_replace-later.pdf |
| Alternate Webpage(s) | https://doi.org/10.1115/gt2018-77290 |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
