Fan Stage Design and Performance Optimization for Low Specific Thrust Turbofans
Paper in proceeding, 2023

In modern turbofan engines the bypass section of the fan stage alone provides the majority of the total thrust in cruise and the size of the fan has a considerable effect on overall engine weight and nacelle drag. Thrust requirements in different parts of the flight envelope must also be satisfied together with sufficient margins towards stall. An accurate description of the interdependencies of relevant performance and design attributes of the fan stage alone - such as efficiency, surge margin, fan-face Mach number, stage loading, flow coefficient and aspect ratio - are therefore necessary to estimate system level objectives such as mission fuel burn and direct operating cost with enough confidence during the conceptual design phase. The contribution of this study is to apply a parametric optimization approach to conceptual design of fan stages for low specific thrust turbofans based on the streamline curvature method. Trade-offs between fan stage attributes for Pareto-optimal solutions are modelled by training a Kriging surrogate model on the results from the parametric optimization. The trends predicted by the resulting surrogate model are analyzed both quantitatively and qualitatively. Most of the trends could be justified with some degree of physical reasoning or comparison with common guidelines from the literature. Trends of stage efficiency with Mach number and stage loading may indicate that shock losses have a larger impact on stage efficiency for designs with low stage loading compared to designs with high stage loading. Means to reduce the strength of the passage shock wave, such as blade sweep, may therefore be of more importance as stage loading is reduced.

PROPULSION

PERFORMANCE

OPTIMIZATION

FANS

TURBOFANS

SURROGATE MODELLING

Author

Oliver Sjögren

Chalmers, Mechanics and Maritime Sciences (M2), Fluid Dynamics

Tomas Grönstedt

Chalmers, Mechanics and Maritime Sciences (M2), Fluid Dynamics

Carlos Xisto

Chalmers, Mechanics and Maritime Sciences (M2), Fluid Dynamics

Anders Lundbladh

GKN Aerospace Services

Chalmers, Mechanics and Maritime Sciences (M2)

International Journal of Turbomachinery, Propulsion and Power

2504186X (eISSN)

15th European Conference on Turbomachinery Fluid Dynamics and Thermodynamics 2023, ETC 2023
Budapest, Hungary,

Fan Alternatives for Next Generation engines 2 (FANG2)

VINNOVA (2023-01193), 2023-07-01 -- 2024-08-31.

Subject Categories

Aerospace Engineering

Energy Engineering

Vehicle Engineering

Fluid Mechanics and Acoustics

DOI

10.3390/ijtpp8040053

More information

Latest update

4/4/2024 1