Composite UHBR Fan for Forced Response and Flutter Investigations

Eggers, Torben; Friedrichs, Jens; Goessling, Jan; Seume, Joerg R.; Natale, N.; Flüh, Jan Peter; Paletta, Nicola

doi:10.1115/gt2021-58941

Cited by 4 publications

(10 citation statements)

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“…The fan blade is modified using the 3D blade design process described in [4]. For the new thickness distribution the maximum thickness position x t was moved upstream in the hub region, from x t = 0.55 to x t = 0.35.…”

Section: Methodsmentioning

confidence: 99%

“…The flutter simulations of the different composite blade designs are performed with the nonlinear research solver TRACE Harmonic Balance (HB) at design speed with a constant static back pressure close to the surge line. For further information on the setups, please refer to the previous publications [4] and [5].…”

Section: Methodsmentioning

confidence: 99%

“…The design process includes steady and unsteady numerical simulation for aerodynamics and aeroelastics respectively. Details about the interdisciplinary and iterative process, as well as the numerical setups are described in [4] and [5]. The fan stage design consists of 18 rotor blades and 40 stator vanes.…”

Section: Fan Stage Designmentioning

confidence: 99%

“…The fan stage design consists of 18 rotor blades and 40 stator vanes. Investigations on the aerodynamic tip gap sensitivity in [6] resulted in a new configuration with an increased tip gap size up to 0.75 mm as the best compromise with mechanical design requirements, compared to the preliminary design in [4] with 0.5 mm in tip gap size. Additionally, the maximum thickness of the blade was reduced by 25% compared to the preliminary design, in order to meet aeroelastic and structural requirements [6].…”

Section: Fan Stage Designmentioning

confidence: 99%

“…S to meet the specifications for fan flutter. For a deeper insight, please refer to the previous work [4]. Based on the improved design that meets the aerodynamic and aeroelastic specifications, a hotcold-transformation of the fan at design loads is performed in an iterative process, using MSC Nastran.…”

Section: Fan Stage Designmentioning

confidence: 99%

See 4 more Smart Citations

Effect of 3D blade design on the aerodynamic, aeroelastic and structural behavior of a scaled UHBR fan

Eggers

Friedrichs

Goessling

et al. 2023

J. Phys.: Conf. Ser.

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In this paper, the effect of a 3D blade design on the aerodynamic, aeroelastic and structural behavior of a scaled UHBR fan is investigated numerically. First, an initial sensitivity analysis for the geometrical design features sweep and lean as well as an adaption of the thickness position in the fan hub region is conducted. Positive sweep is found to benefit the total pressure ratio, while positive lean improves the polytropic efficiency of the fan stage. Moving the maximum thickness position upwards leads to decreased flow turning and total pressure ratio. The mode shape and by that the twist-to-plunge ratio of the first mode is significantly influenced by the modifications. Thus, changing the aerodynamic damping of the blade and influencing the flutter behavior of the fan. Additionally, the fan displacements under aerodynamic and rotational loads are affected. For the fan presented a positive lean causes the blade to bend towards the pressure side when subjected to inertial forces, countering deformation from aerodynamic loads. Thickness adaption moves the shear center of the cross sections to the back. These results are used to optimize the fan blade behavior to achieve the project’s objectives. A final design, which satisfies the aerodynamic, aeroelastic and structrual needs of the CA3ViAR fan stage, is presented.

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Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Fan Stage Designmentioning

confidence: 99%

Section: Fan Stage Designmentioning

confidence: 99%

Section: Fan Stage Designmentioning

confidence: 99%

See 3 more Smart Citations

Effect of 3D blade design on the aerodynamic, aeroelastic and structural behavior of a scaled UHBR fan

Eggers

Friedrichs

Goessling

et al. 2023

J. Phys.: Conf. Ser.

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High-speed Digital Image Correlation (DIC) for measuring deformation and vibration of fast rotating fan blades

Goessling

Seume

2023

J. Phys.: Conf. Ser.

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Due to ecological requirements, the bypass-ratio of future civil turbofan engines will be increased. This leads to ultra-high bypass ratio (UHBR) engines, which bring in new challenges concerning the blade material, structural integration, and aeroelastic behaviour of the fan. The ambition of the project Composite fan Aerodynamic, Aeroelastic, and Aeroacoustic Validation Rig (CA3ViAR) is to design and test an open-test-case fan that experiences instability mechanisms, which are representative for UHBR fans of civil aircrafts. The optical measurement technique Digital Image Correlation (DIC) allows for the spatial measurement of deformations. The aim is to apply this technique to measure rotor blade deformation under loading and its vibration due to aeroelastic phenomena to get a better understanding of the structural and aeroelastic behaviour of the composite fan. However, the high rotational speeds, blade vibration frequencies, and expected amplitudes pose challenges for the measurement setup. In this work, a high-speed DIC system is prepared and tested to measure deformation and vibration of a fast rotating blade. Additionally, the requirements for the DIC setup are defined and presented. The expected blade tip speeds in the CA3ViAR project are up to 295 m/s and the blade frequencies of interest up to 650 Hz. Therefore, particular emphasis must be given to the setup in order to eliminate motion blur due to the rotation and to achieve the required frequency. This leads to a setup with synchronised high-speed cameras and a laser to measure frequency vibrations up to 1 kHz with an exposure time below 210 ns. Test measurements are conducted on a stationary beam and an axial blower with a max. blade tip speed of 50 m/s. A data analysis method is developed and described to eliminate the rigid body rotation, analyse the deformation of each blade compared to a reference condition, and analyse the spatial vibration in the frequency domain for a high number of data points per time step. The results of the structural beam are in agreement with the reference measurements and numerical simulations. By analysing the spatial vibration modes of the axial blower, the 1F-flap mode is identified at 38 Hz. In conclusion, this DIC setup shows promising results for future deformation and vibration measurements on a scaled UHBR fan.

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Experiments on Tuned UHBR Open-Test-Case Fan ECL5/CATANA: Performance and Aerodynamics

Schneider,

Fiquet,

Paoletti

et al. 2024

Journal of Turbomachinery

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With the advancement of modern fan architectures the lack of experimental benchmarks for the research community became apparent in recent years. Enormous effort in method development could not be validated on representative geometries and motivated the development of the open-test-case ECL5/CATANA. A carbon fibre fan stage has been designed by Ecole Centrale de Lyon and shared with the community in 2021. The fan is representative of modern UHBR architectures with sonic design speed. The reference configuration has been investigated experimentally with multi-physical instrumentation. In this publication the results of the first experimental campaign are presented with a detailed analysis of the aerodynamic performance and system symmetry. The presented results comprise full stage mappings across the whole operating range for three main speedlines (55%, 80% and 100%) using performance rakes, unsteady wallpressure arrays, tip-clearance and stagger-angle measurements. Radial profiles of intake boundary layer and rotor-exit conditions at selected conditions complete the full validation dataset for steady and unsteady aerodynamic simulations. Results are discussed in comparison to blind-test RANS simulations of different international institutes. Significant predicition inaccuracies of the tip flow and corner separations of the stator are observed and reveal the requirement of real-blade-geometry measurements at running conditions. This paper is accompanied by a publication with a focus on aeroelastic instabilities observed near the stability limit. The results represent a comprehensive dimensional benchmark dataset and allow method validation on multiple levels of fidelity for the aerodynamic and aeroelastic research community.

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Composite UHBR Fan for Forced Response and Flutter Investigations

Cited by 4 publications

References 0 publications

Effect of 3D blade design on the aerodynamic, aeroelastic and structural behavior of a scaled UHBR fan

Effect of 3D blade design on the aerodynamic, aeroelastic and structural behavior of a scaled UHBR fan

High-speed Digital Image Correlation (DIC) for measuring deformation and vibration of fast rotating fan blades

Experiments on Tuned UHBR Open-Test-Case Fan ECL5/CATANA: Performance and Aerodynamics

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