0
Research Papers

Numerical and Experimental Comparison of a Tandem and Single Vane Deswirler Used in an Aero Engine Centrifugal Compressor

[+] Author and Article Information
Peter Jeschke

Institute of Jet Propulsion and Turbomachinery,
RWTH Aachen University,
Templergraben 55,
Aachen 52062, Germany
e-mail: jeschke@ist.rwth-aachen.de

Caitlin Smythe

GE Aviation,
1000 Western Avenue MD47410,
Lynn, MA 01910
e-mail: caitlin.smythe@ge.com

Except for some small areas in the transonic inlet of the diffuser.

For the presented investigation the shroud pressure build-up is not available for the SNG case.

Although the averaging method is not conservative, this method serves the purpose of visualizing the weak areas well, due to the fact that the flow field is not weighted.

1Corresponding author.

Contributed by the International Gas Turbine Institute (IGTI) of ASME for publication in the Journal of Turbomachinery. Manuscript received May 3, 2013; final manuscript received June 20, 2013; published online September 26, 2013. Editor: Ronald Bunker.

J. Turbomach 136(4), 041005 (Sep 26, 2013) (10 pages) Paper No: TURBO-13-1067; doi: 10.1115/1.4024891 History: Received May 03, 2013; Revised June 20, 2013

The present work is part of the research project at the Institute of Jet Propulsion and Turbomachinery at the RWTH Aachen University in collaboration with GE Aviation. The subject is the numerical and experimental analysis of two blading strategies used in the diffusion system of an aero engine centrifugal compressor. The transonic centrifugal compressor investigated contains a close-coupled impeller and passage diffuser, followed by a deswirler system. The deswirler redirects the flow towards the combustion chamber, while decreasing swirl and recovering pressure. It is characterized by a high aerodynamic loading, due to a moderate inlet Mach number of 0.35, in combination with a required flow redirection of 70 deg in circumferential and 135 deg in meridional direction. For this purpose, two different blading strategies are investigated, both retaining the same meridional flow path and integral chord length. The first design is a tandem configuration with 30 vanes in the first row and 60 vanes in the second row. In principal, this approach benefits from the small wetted surface, the short and thereby stable boundary layers as well as the positive blade interaction due to the close alignment. The second design contains one row of 75 vanes. The higher solidity is needed to compensate for the longer boundary layers. The two deswirlers investigated are compared to a less compact baseline deswirler with simple prismatic vanes. Experimental and numerical data shows that both new configurations have very similar stage efficiency. The single row design shows a higher static pressure recovery, resulting in a +0.2%-points total-to-static isentropic efficiency increase compared to the tandem design. Detailed flow analysis in the deswirler system shows different characteristics in terms of losses, loss mechanisms and pressure build-up. Due to the required high turning, both designs suffer from flow separation. Nevertheless, the single row design shows its robustness under the impact of 3D flow, whereas the tandem suffers from end wall induced losses. The results show that the classical mechanisms making a tandem favorable for high flow turning in 2D flow are counteracted by 3D flow mechanisms caused by the spanwise pressure gradient. The low aspect ratio even increases the effect of 3D end wall mechanisms. These results, combined with a higher manufacturing effort, show that a tandem configuration is not necessarily the superior design for highly 3D flow conditions.

FIGURES IN THIS ARTICLE
<>
Copyright © 2014 by ASME
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Fig. 1

3D view of the three deswirler configurations

Grahic Jump Location
Fig. 2

Cross-sectional view of the test rig

Grahic Jump Location
Fig. 3

3D view of the CFD domain of the centrifugal stage

Grahic Jump Location
Fig. 4

Schematical view of the GE-centrifugal stage

Grahic Jump Location
Fig. 5

ωdiff,norm and Cpdiff,norm over the corrected mass flow at the diffuser inlet calculated between plane 4M and 7M shown in Fig. 4

Grahic Jump Location
Fig. 6

Experimental and numerical diffuser meanline pressure buildup

Grahic Jump Location
Fig. 7

Blade-to-blade loading at 50% span

Grahic Jump Location
Fig. 8

Hub and shroud loading at the centerline in between the deswirler blades

Grahic Jump Location
Fig. 9

Flux-averaged streamwise development of ωnorm

Grahic Jump Location
Fig. 10

Flux-averaged streamwise development of Cpnorm

Grahic Jump Location
Fig. 11

Flux-averaged streamwise development of the flow-angle α

Grahic Jump Location
Fig. 12

Entropy distribution in the TND deswirler

Grahic Jump Location
Fig. 13

Entropy distribution in the SNG deswirler

Grahic Jump Location
Fig. 14

Sources for the 3D flow within the TND deswirler

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