Assessing aircraft noise for quieter take-off and landing
To date, the most important SilentProp achievement concerns noise assessment. The researchers revealed the effects of flight conditions and propeller installation on the aerodynamics and noise of DEP aircraft. “Propeller noise can be reduced by leading-edge installations and the noise generation mechanism can vary between take-off and landing conditions,” explains Richard Jefferson-Loveday of project coordinator University of Nottingham in the United Kingdom. Another key finding involves numerical methods. Project partners developed new numerical models to predict single and multiple propeller noise and the fuselage vibroacoustic response. Yet another notable accomplishment has to do with noise and vibration suppressing. The partners developed and assessed techniques to suppress the DEP noise and vibration by using propeller phase locking, propeller shielding, locally resonant metamaterials and porous-media fuselage filling.
Achieving optimal designs for DEP configurations
Numerical simulations and virtual engineering work demonstrated the use of phase locking to reduce noise levels of DEP and/or urban air mobility (UAM) systems by carefully maintaining specific phase angles between the propellers. The trends observed in the phase locking simulations were validated in laboratory measurements. “The knowledge of the impacts of the relative phase angle between propellers on the system’s noise emission can inform UAM designers and help original equipment manufacturers achieve quiet urban air travel,” states Jefferson-Loveday. Simulation work involved modelling acoustics of various components and their interactions over large computing clusters across the United Kingdom. The data obtained from the high-fidelity numerical simulations and other data sources are being used to train sophisticated machine learning models in predicting propeller noise. The SilentProp team has successfully trained the algorithm to predict propeller noise. Other research has shown promise in the development of acoustic metamaterials that can reduce broadband noise and vibration. This will improve the experience of flight passengers, while decreasing noise emitted by the vehicle. SilentProp (Development of computational and experimental noise assessment and suppression methodologies for the next generation of silent distributed propulsion configurations) ends in September 2023. If you are interested in having your project featured as a ‘Project of the Month’ in an upcoming issue, please send us an email to editorial@cordis.europa.eu and tell us why!
Keywords
SilentProp, distributed electric propulsion, noise, aircraft, propeller