Full Content is available to subscribers

Subscribe/Learn More  >

Computational Study of Geometric Parameter Influence on Aggressive Inter-Turbine Duct Performance

[+] Author Affiliations
Paul T. Couey, Craig W. McKeever, Malak F. Malak

Honeywell Aerospace, Phoenix, AZ

S. Balamurugan, H. Raju Veeraraghava, R. Dhinagaran

Honeywell Technology Solutions, Bangalore, India

Paper No. GT2010-23604, pp. 1647-1656; 10 pages
  • ASME Turbo Expo 2010: Power for Land, Sea, and Air
  • Volume 7: Turbomachinery, Parts A, B, and C
  • Glasgow, UK, June 14–18, 2010
  • Conference Sponsors: International Gas Turbine Institute
  • ISBN: 978-0-7918-4402-1 | eISBN: 978-0-7918-3872-3
  • Copyright © 2010 by ASME


Modern direct-drive turbofan engines typically have the fan turbine designed at significantly higher diameter than the gas producer turbine. Furthermore, the gas turbine industry is being pushed to shorten engine length with the goal of reducing weight. This results in a need to design very aggressive inter-turbine-ducts (ITD’s) that have high endwall slopes. The gas turbine design cycle typically begins with conceptual design where many engine configuration iterations are made. During conceptual design, there usually is little firm geometric definition or time for detailed CFD studies on aggressive ITD’s. This can cause a large amount of risk to the engine development schedule and cost if the space allocated for the ITD during conceptual design is found to be insufficient later in the design cycle. Therefore, simple analytical tools for accurately assessing the risk of an ITD in conceptual design are important. The gas turbine industry is familiar with the Sovran and Klomp annular diffuser performance chart [1] as a conceptual design tool for assessing ITD’s. However, its applicability to modern gas turbine ducts with high endwall slope is limited. The location of the maximum pressure recovery for a given length, the Cp* line, considers only two geometric parameters: area ratio and normalized length. The chart makes no distinction of risk of flow separation regarding the level of slope or the pitch-wise turning in the duct. However, intuition would suggest that a high slope duct would have more risk of separation than an equivalent area ratio duct with low slope. Similarly, a duct that turns the flow from axial to radial would be expected to be riskier than a pure axial duct. To help assess the interaction of duct slope and pitch-wise turning with area ratio and length, an analytical Design of Experiments (DOE) was run using approximately sixty different duct configurations. The DOE was carried out using 3D, steady CFD analysis. The results of the DOE are presented with insights provided into how the Cp* line may shift as a function of duct slope. Of particular interest is that slope by itself does not work particularly well as a risk indicator. However, a combination of new area ratio-length and slope-length parameters was found to segregate ducts between separated and non-separated cases.

Copyright © 2010 by ASME
Topics: Turbines , Ducts



Interactive Graphics


Country-Specific Mortality and Growth Failure in Infancy and Yound Children and Association With Material Stature

Use interactive graphics and maps to view and sort country-specific infant and early dhildhood mortality and growth failure data and their association with maternal

Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In