0
Research Papers

Optimization of Nonaxisymmetric Endwalls in Compressor S-Shaped Ducts

[+] Author and Article Information
Edward M. J. Naylor, Cecilia Ortiz Dueñas, Robert J. Miller, Howard P. Hodson

Whittle Laboratory, University of Cambridge, Cambridge, Cambridgeshire CB3 0DY, UK

J. Turbomach 132(1), 011011 (Sep 17, 2009) (10 pages) doi:10.1115/1.3103927 History: Received September 01, 2008; Revised December 17, 2008; Published September 17, 2009

This paper presents a new design methodology for strutted S-shaped compressor ducts that allows for more aggressive designs while maintaining current levels of duct loss. A baseline duct geometry was selected, which had a radius change to length ratio that is 34% larger than current engine design limits. A large-scale low-speed model of the baseline duct was experimentally tested. The flow in the corner between the hub and the strut was found to separate due to the high local diffusion causing an increase in duct loss. Area ruling was applied to the baseline duct and was predicted to reduce the size and extent of the strut-hub corner separation, but the duct design was compromised. The duct loss coefficient at midpitch was predicted to increase compared with that of the baseline design. Nonaxisymmetric endwall profiling was then used on the duct wall, locally to the strut, to remove the strut-hub corner separation and thus reduce net duct loss, without compromising the duct design away from the strut. The endwall geometry was produced by numerical optimization. It was shown that the net duct loss was insensitive to casing profiling but highly sensitive to hub profiling. The optimal hub geometry was experimentally tested and shown to completely remove endwall strut-hub corner separation. The profiling was found to reduce the net duct loss by 16%. The paper shows that the key benefit to endwall profiling is that it can be used to safely increase the size of the design space in which aeroengine duct designers can operate.

Copyright © 2010 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 21

Flow visualization on the surface of the strut for the nonaxisymmetric experimental test

Grahic Jump Location
Figure 22

Measured exit contours of total pressure coefficient for nonaxisymmetric test

Grahic Jump Location
Figure 20

Measured Cp at 10% of span with and without endwall profiling

Grahic Jump Location
Figure 19

Computed exit total pressure coefficient of the optimal design

Grahic Jump Location
Figure 18

Computed near wall streamlines for the predicted optimal design

Grahic Jump Location
Figure 17

Computed optimum hub Cp distribution on the hub endwall and lines of perturbation height

Grahic Jump Location
Figure 16

Computed baseline Cp distribution on the hub endwall

Grahic Jump Location
Figure 15

Predicted optimal hub endwall design. Contours of perturbation height as a fraction of hin.

Grahic Jump Location
Figure 14

Computed Cp distributions at the strut-hub interface

Grahic Jump Location
Figure 13

Predicted Pareto solutions for the fifth update to response surface

Grahic Jump Location
Figure 12

Axial location of control points

Grahic Jump Location
Figure 11

Computed near wall streamlines on the axisymmetric profiled design

Grahic Jump Location
Figure 10

Computed near wall streamlines on the baseline strut

Grahic Jump Location
Figure 9

Computed exit total pressure coefficient for the axisymmetric profiled design

Grahic Jump Location
Figure 8

Computed exit total pressure coefficient for the baseline design

Grahic Jump Location
Figure 7

Area distribution of Duct74, baseline duct, and area-ruled duct with blockage of strut removed

Grahic Jump Location
Figure 6

Measured exit contours of total pressure coefficient for 74% length duct

Grahic Jump Location
Figure 5

Flow visualization on the surface of the strut in the 74% length duct experimental test

Grahic Jump Location
Figure 4

Measured strut pressure distribution compared with the inviscid static pressure distribution for 74% length duct

Grahic Jump Location
Figure 3

Net duct loss for unstrutted and strutted ducts

Grahic Jump Location
Figure 1

Schematic of the duct pressure fields

Tables

Errata

Discussions

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