Research Papers

Toward the Expansion of Low-Pressure-Turbine Airfoil Design Space

[+] Author and Article Information
E. A. Grover

United Technologies,
Pratt & Whitney,
East Hartford, CT 06108

S. A. Sjolander

Department of Mechanical and
Aerospace Engineering,
Carleton University,
Ottawa, ON K1S 5B6, Canada

R. Sondergaard

Air Force Research Laboratory,
WPAFB, OH 45433

Contributed by the International Gas Turbine Institute (IGTI) of ASME for publication in JOURNAL OF TURBOMACHINERY. Manuscript received March 21, 2011; final manuscript received January 28, 2013; published online September 13, 2013. Editor: David Wisler.

J. Turbomach 135(6), 061007 (Sep 13, 2013) (8 pages) Paper No: TURBO-11-1046; doi: 10.1115/1.4024796 History: Received March 21, 2011; Revised January 28, 2013

Future engine requirements, including high-altitude flight of unmanned air vehicles as well as an impetus to reduce engine cost and weight, are challenging the current state of the art in low-pressure-turbine airfoil design. These new requirements present low-Reynolds number challenges as well as the need for high-performance, high-lift design concepts. Here, we report on an effort to expand the relatively well established aerodynamic design space for low-pressure turbine airfoils through the application of recent developments in transition modeling to airfoil design. Analytical and experimental midspan performance data and predicted loadings are presented for four high-lift airfoil designs based on the Pack B velocity triangles. The new designs represent a systematic expansion of low-pressure turbine airfoil design space through the application of high-lift design concepts for front- and aft-loaded airfoils. All four designs performed as predicted across a range of operationally representative Reynolds numbers. Full-span loss data for the new high-lift designs reveal increased endwall losses, which, with the application of nonaxisymmetric endwall contouring, have been substantially reduced. Taken holistically, the results presented here demonstrate that accurate transition modeling provides a reliable method to develop optimized, very high-lift airfoil designs. However, further improvements in endwall-loss mitigation technologies are required to enable the implementation of the very high-lift technology presented here in engine systems.

Copyright © 2013 by ASME
Your Session has timed out. Please sign back in to continue.



Grahic Jump Location
Fig. 1

Low-pressure turbine airfoil counts as a function of pressure ratio demonstrating the trend toward reduced count

Grahic Jump Location
Fig. 2

Four high-lift airfoil designs compared to the baseline Pack B design

Grahic Jump Location
Fig. 3

Design-intent loading distribution for the baseline Pack B airfoil design

Grahic Jump Location
Fig. 4

Pack B loss data from both the CU and WP test facilities. Also plotted are steady loss data for the U1 airfoil design of Howell et al. [5].

Grahic Jump Location
Fig. 5

Pack D-A and D-F surface static-pressure distributions compared with the Pack B loading

Grahic Jump Location
Fig. 6

Comparisons of Pack D-A and D-F measured losses with Pack B included for reference

Grahic Jump Location
Fig. 7

Pack E and F surface pressure distributions with the baseline Pack B shown for reference

Grahic Jump Location
Fig. 8

Pack E and F measured loss data versus Reynolds number with Pack B data included for reference

Grahic Jump Location
Fig. 9

Comparison of loss-versus-Reynolds number characteristics for the four high-lift and baseline Pack B designs with power-law fits for each data set

Grahic Jump Location
Fig. 10

Midspan losses for Pack B, D-A, and D-F designs as a function of the reduced frequency of unsteady bar-generated wake passing

Grahic Jump Location
Fig. 11

Unsteady loss data for Pack B, D-F, and the U1 airfoil design of Howell et al. [5]. The steady losses for Pack B are included for reference.

Grahic Jump Location
Fig. 12

Endwall contouring applied to the Pack D-F design. A single airfoil is shown in this image.

Grahic Jump Location
Fig. 13

Comparisons of the spanwise loss distributions for Pack B and D-F with planar endwalls and Pack D-F with contoured endwalls




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 Journal Articles
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