Fan Stage Design and Performance Optimization for Low Specific Thrust Turbofans

In modern turbofan engines, the bypass section of the fan stage alone provides the majority of the total thrust required in cruise, and the size of the fan has a considerable effect on the overall engine weight and nacelle drag. Thrust requirements in different parts of the flight envelope must also...

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Main Authors: Oliver Sjögren, Tomas Grönstedt, Anders Lundbladh, Carlos Xisto
Format: Article
Language:English
Published: MDPI AG 2023-12-01
Series:International Journal of Turbomachinery, Propulsion and Power
Subjects:
Online Access:https://www.mdpi.com/2504-186X/8/4/53
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author Oliver Sjögren
Tomas Grönstedt
Anders Lundbladh
Carlos Xisto
author_facet Oliver Sjögren
Tomas Grönstedt
Anders Lundbladh
Carlos Xisto
author_sort Oliver Sjögren
collection DOAJ
description In modern turbofan engines, the bypass section of the fan stage alone provides the majority of the total thrust required in cruise, and the size of the fan has a considerable effect on the overall engine weight and nacelle drag. Thrust requirements in different parts of the flight envelope must also be satisfied together with sufficient margins towards stalling. An accurate description of the interdependencies between the 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 the direct operating cost with enough confidence during the conceptual design phase. The contribution of this study is to apply a parametric optimization approach to the 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 modeled by training Kriging surrogate models on the results from the parametric optimization. A case study is provided in the end to demonstrate the potential implications of including a higher level of fan-stage parameter interdependency in an engine systems model. Results implied that being able to predict the rotor solidity required to maintain a given average blade loading—in addition to stage efficiency—is of significant importance when it comes to evaluating the trade-off between engine weight and thrust-specific fuel consumption.
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spelling doaj.art-92e7bd075b0846dbb752bf83608fd4872023-12-22T14:15:41ZengMDPI AGInternational Journal of Turbomachinery, Propulsion and Power2504-186X2023-12-01845310.3390/ijtpp8040053Fan Stage Design and Performance Optimization for Low Specific Thrust TurbofansOliver Sjögren0Tomas Grönstedt1Anders Lundbladh2Carlos Xisto3Department of Mechanics and Maritime Sciences, Chalmers University of Technology, 41296 Gothenburg, SwedenDepartment of Mechanics and Maritime Sciences, Chalmers University of Technology, 41296 Gothenburg, SwedenDepartment of Mechanics and Maritime Sciences, Chalmers University of Technology, 41296 Gothenburg, SwedenDepartment of Mechanics and Maritime Sciences, Chalmers University of Technology, 41296 Gothenburg, SwedenIn modern turbofan engines, the bypass section of the fan stage alone provides the majority of the total thrust required in cruise, and the size of the fan has a considerable effect on the overall engine weight and nacelle drag. Thrust requirements in different parts of the flight envelope must also be satisfied together with sufficient margins towards stalling. An accurate description of the interdependencies between the 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 the direct operating cost with enough confidence during the conceptual design phase. The contribution of this study is to apply a parametric optimization approach to the 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 modeled by training Kriging surrogate models on the results from the parametric optimization. A case study is provided in the end to demonstrate the potential implications of including a higher level of fan-stage parameter interdependency in an engine systems model. Results implied that being able to predict the rotor solidity required to maintain a given average blade loading—in addition to stage efficiency—is of significant importance when it comes to evaluating the trade-off between engine weight and thrust-specific fuel consumption.https://www.mdpi.com/2504-186X/8/4/53fansoptimizationperformanceturbofanspropulsionsurrogate modeling
spellingShingle Oliver Sjögren
Tomas Grönstedt
Anders Lundbladh
Carlos Xisto
Fan Stage Design and Performance Optimization for Low Specific Thrust Turbofans
International Journal of Turbomachinery, Propulsion and Power
fans
optimization
performance
turbofans
propulsion
surrogate modeling
title Fan Stage Design and Performance Optimization for Low Specific Thrust Turbofans
title_full Fan Stage Design and Performance Optimization for Low Specific Thrust Turbofans
title_fullStr Fan Stage Design and Performance Optimization for Low Specific Thrust Turbofans
title_full_unstemmed Fan Stage Design and Performance Optimization for Low Specific Thrust Turbofans
title_short Fan Stage Design and Performance Optimization for Low Specific Thrust Turbofans
title_sort fan stage design and performance optimization for low specific thrust turbofans
topic fans
optimization
performance
turbofans
propulsion
surrogate modeling
url https://www.mdpi.com/2504-186X/8/4/53
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AT tomasgronstedt fanstagedesignandperformanceoptimizationforlowspecificthrustturbofans
AT anderslundbladh fanstagedesignandperformanceoptimizationforlowspecificthrustturbofans
AT carlosxisto fanstagedesignandperformanceoptimizationforlowspecificthrustturbofans