An Experimental Study of the Aeroacoustic Properties of a Propeller in Energy Harvesting Configuration

Abstract

The aim of the present manuscript is to investigate the noise footprint of an isolated propeller in different flight configurations for the propulsion of a hybrid-electric aircraft. Experimental tests were performed at the Low-Turbulence Tunnel located at Delft University of Technology with a powered propeller model and flush-mounted microphones in the tunnel floor. The propeller was investigated at different advance ratios in order to study the noise impact in propulsive and energy harvesting configurations. For brevity, this work only reports the results at the conditions of maximum efficiency in both propulsive and energy harvesting regimes, for a fixed blade pitch setting. Comparing these two configurations, a frequency-domain analysis reveals a significant modification in the nature of the noise source. In the propulsive configuration, most of the energy is related to the tonal noise component, as expected for an isolated propeller; however, in energy harvesting configuration, the broadband noise component increases significantly compared to the propulsive mode. A more detailed analysis requires separation of the two noise components and, for this purpose, an innovative decomposition strategy based on proper orthogonal decomposition (POD) has been defined. This novel technique shows promising results; both in the time and in the Fourier domains the two reconstructed components perfectly describe the original signal and no phase delays or other mathematical artifices are introduced. In this sense, it can represent a very powerful tool to identify noise sources and, at the same time, to define a proper control strategy aimed at noise mitigation.

Aeroacoustics Analysis of Propeller Blade

“…The pressure and velocity over the propeller blade with pitch 25degrees is analyzed and studied the pressure and velocity contours as shown below Figures 11 to 13 To calculate Thrust force the analysis of the pressure and velocity is important from the contours of pressure and velocity we can determine the aerodynamic property of propeller blade [4].…”

Cross-Wavelet Analysis on Radiation Emitted by the plume of a small-size Solid Rocket Motor

“…Wavelet based post processing tecnique has been one of the most used methods to analyze randomical data. Starting from 3 decades ago [8,9] one of the best application of this analysis is on turbulent flows experimental or numerical data, in the large amount of literature the authors suggest [10,11,12]. Theoretical aspects of wavelet analysis are presented by [13] where also cross-wavelet analysis is introduced.…”

Set-Based Design Space Exploration to Investigate the Effect of Energy Storage Durability on the Energy Management Strategy of a Hybrid-Electric Aircraft

“…Currently, few studies have been published targeting this specific problem but limited to the Urban Air Mobility (UAM) sector [5,6]. This gap falls within the scope of the FutPrint50 project [7], which aims to identify and assess the role of the key technologies required for the successful implementation of hybrid-electric propulsion for regional turboprop airplanes [8][9][10]. Alongside this technical goal, the project aims to develop a design space exploration and optimization framework that takes into consideration the uncertainty of a new design and provides multiple alternatives in deciding which concept to pursue for a given set of top level requirements.…”