Full Content is available to subscribers

Subscribe/Learn More  >

Fast Optimisation of a Three-Dimensional Bypass System Using a New Aerodynamic Design Method

[+] Author Affiliations
F. Barbarossa, M. E. Rife, M. Carnevale, L. di Mare

Imperial College London, London, UK

A. B. Parry, J. S. Green

Rolls Royce, Derby, UK

Paper No. GT2017-63324, pp. V02BT41A010; 10 pages
  • ASME Turbo Expo 2017: Turbomachinery Technical Conference and Exposition
  • Volume 2B: Turbomachinery
  • Charlotte, North Carolina, USA, June 26–30, 2017
  • Conference Sponsors: International Gas Turbine Institute
  • ISBN: 978-0-7918-5079-4
  • Copyright © 2017 by Rolls-Royce plc


The propulsive efficiency of civil aviation power plants can be effectively improved by increasing the bypass ratio. Higher bypass ratios, however, exacerbate issues of performance, stability and integrity due to the interaction between the engine pylon, the outlet guide vanes (OGV) and the fan. These issues are due to the distortion of the static pressure field at fan exit due to the presence of the pylon and its transmission through the OGV bladerow and are more pronounced the closer the components of the low pressure compression (LPC) system are. These issues make a rational and effective design of the LPC system of paramount importance for the success of very high-bypass ratio engines.

At the preliminary design phase, methods that utilise computational fluid dynamics (CFD) are prohibitively expensive, particularly if they are used as part of optimisation processes involving highly three dimensional, non-axisymmetric OGV designs. An alternative method is being developed exploiting the simplicity and the accuracy of surface singularity element methods to investigate the sensitivity of the bypass system to changes in the design variables. Although the singularity method is based on simplified assumptions of inviscid, incompressible flow, it still performs remarkably well when combined with a tailored optimisation technique. This paper discusses the optimisation framework in detail, including the underlying mathematical models that describe the three-dimensional aerodynamic flowfield as well as the optimisation tools, variables and cost functions used within the optimisation process. The results show that the proposed approach can be used to explore quickly and efficiently a far wider design space than attempted so far in literature. Furthermore, the proposed method leads to non-axysymmetric cascade designs whereby every vane has the same load as the nominal vane whilst greatly reducing the static pressure distortion at fan exit.

Copyright © 2017 by Rolls-Royce plc



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