TY  - JOUR
A1  - Bergmann, Ole
A1  - Möhren, Felix
A1  - Braun, Carsten
A1  - Janser, Frank
T1  - On the influence of elasticity on swept propeller noise
JF  - AIAA SCITECH 2023 Forum
N2  - High aerodynamic efficiency requires propellers with high aspect ratios, while propeller sweep potentially reduces noise. Propeller sweep and high aspect ratios increase elasticity and coupling of structural mechanics and aerodynamics, affecting the propeller performance and noise. Therefore, this paper analyzes the influence of elasticity on forward-swept, backward-swept, and unswept propellers in hover conditions. A reduced-order blade element momentum approach is coupled with a one-dimensional Timoshenko beam theory and Farassat's formulation 1A. The results of the aeroelastic simulation are used as input for the aeroacoustic calculation. The analysis shows that elasticity influences noise radiation because thickness and loading noise respond differently to deformations. In the case of the backward-swept propeller, the location of the maximum sound pressure level shifts forward by 0.5 °, while in the case of the forward-swept propeller, it shifts backward by 0.5 °. Therefore, aeroacoustic optimization requires the consideration of propeller deformation.
Y1  - 2023
U6  - http://dx.doi.org/10.2514/6.2023-0210
N1  - Session: Propeller, Open Rotor, and Rotorcraft Noise II

AIAA SCITECH 2023 Forum, 23-27 January 2023, National Harbor, MD & Online
PB  - AIAA
ER  - 
TY  - JOUR
A1  - Möhren, Felix
A1  - Bergmann, Ole
A1  - Janser, Frank
A1  - Braun, Carsten
T1  - On the influence of elasticity on propeller performance: a parametric study
JF  - CEAS Aeronautical Journal
N2  - The aerodynamic performance of propellers strongly depends on their geometry and, consequently, on aeroelastic deformations. Knowledge of the extent of the impact is crucial for overall aircraft performance. An integrated simulation environment for steady aeroelastic propeller simulations is presented. The simulation environment is applied to determine the impact of elastic deformations on the aerodynamic propeller performance. The aerodynamic module includes a blade element momentum approach to calculate aerodynamic loads. The structural module is based on finite beam elements, according to Timoshenko theory, including moderate deflections. Several fixed-pitch propellers with thin-walled cross sections made of both isotropic and non-isotropic materials are investigated. The essential parameters are varied: diameter, disc loading, sweep, material, rotational, and flight velocity. The relative change of thrust between rigid and elastic blades quantifies the impact of propeller elasticity. Swept propellers of large diameters or low disc loadings can decrease the thrust significantly. High flight velocities and low material stiffness amplify this tendency. Performance calculations without consideration of propeller elasticity can lead to decreased efficiency. To avoid cost- and time-intense redesigns, propeller elasticity should be considered for swept planforms and low disc loadings.
KW  - Propeller
KW  - Finite element method
KW  - Blade element method
KW  - Propeller elasticity
KW  - Aeroelasticity
Y1  - 2023
U6  - http://dx.doi.org/10.1007/s13272-023-00649-y
SN  - 1869-5590 (Online)
SN  - 1869-5582 (Print)
N1  - Corresponding author: Felix Möhren
VL  - 14
SP  - 311
EP  - 323
PB  - Springer Nature
CY  - Berlin
ER  -