In the framework of the MATIM project, an acoustic test campaign was conducted on a platform derived from a commercial-class quadcopter within the CIRA semi-anechoic chamber. A dedicated rotor rig allowed systematic measurements of thrust, torque, and shaft speed together with near- and far-field noise using ten calibrated 1/2-inch precision microphones. Three configurations were examined: an isolated rotor, the same rotor mounted on an aluminium quadcopter plate, and the full four-rotor assembly. The resulting data set, acquired over 3000–8000 rpm, documents the azimuthal directivity and radial decay of tonal and broadband noise while separating motor, propeller, and installation contributions. Analysis shows that a nearby rigid plate scatters part of the sound field towards frontal and oblique observers and produces a shielding effect in the rotor plane. The combined operation of four rotors further redistributes energy and broadens blade-passing frequency harmonics. The database is intended as a benchmark for aeroacoustics codes and for the development of reduced-order models.

A rocket’s turbulent jet radiates intense acoustic waves, which are an acoustic load for structural components like payload, launch structure, and rocket avionics, and impact communities near the launch site. Therefore, a careful characterization of the acoustic field produced by a rocket engine can provide crucial information during the design phase. In particular, this deals with improving the understanding of the acoustics of low-thrust hybrid rocket engines. Since an accurate jet noise detection around the entire launch site is time-consuming and extremely cost-prohibitive, a fast and reliable predictive tool is invaluable. For this purpose, a semi-empirical model was employed, using the exhaust plume property and geometric characteristics of the nozzle as input. Experimental data collected during a firing test campaign, conducted in the framework of HYPROB-NEW project by the Italian Aerospace Research Center, were decisive to discuss the validity of the model also for low-thrust hybrid propulsion and support the goodness of the noise curves and metrics estimated for nearby regions and provide considerations about the implications of engine geometric characteristics on noise emissions.

Fuel cells offer a promising route to eliminating in-flight emissions from regional aviation, but certification requires proof that stacks can withstand the vibration and shock environment of turboprop aircraft. As part of the EU-funded NEWBORN project, we combined detailed finite element modeling with shaker tests to evaluate the vibration immunity of PowerCell Group’s prototype stack. The numerical model combined an orthotropic, two-zone 3D mesh of the cell package with reduced-order representations of plates, compression bands, disc springs and the mounting cage. The assembled stack was excited between 10 and 300 Hz using pseudo-random and sine-sweep inputs up to 2.0 g, from which 54 frequency response functions were obtained. The tuned model accurately reproduced the first global modes and captured the overall dynamic behavior with good, though not perfect, agreement. The combined numerical–experimental methodology therefore offers a framework for refining test campaigns and delivering early, qualitative evidence of vibration immunity in fuel cell stacks destined for flight.

The growing need to reduce aviation’s carbon footprint and reliance on fossil fuels has prompted the exploration of alternative propulsion technologies. Fuel cell (FC) systems offer a sustainable solution, generating only water vapor as a by-product. This paper presents a conceptual study, focusing on subsystem integration and safety aspects, for an 80-passenger, hydrogen-powered aircraft developed within the European Union (EU) co-funded NEWBORN (NExt generation high poWer fuel cells for airBORNe applications) Project. The designed configuration incorporates wing-mounted pods housing fuel cells, an electric motor, an inverter, a Thermal Management System (TMS), and Balance of Performance (BoP). This configuration is an effort towards environmentally friendly solutions, addressing climate change and paving the way towards greener aviation.

This study presents a surrogate modeling framework designed for the rapid yet reliable assessment of sonic boom impacts. The methodology is demonstrated through two case studies: a transatlantic flight from Milan to New York, highlighting the sonic boom impact along the route; and a representative supersonic overflight of Italy, quantifying the population exposure to varying noise levels. Aerodynamic numerical simulations were carried out using an open-source code to capture near-field pressure signatures at three critical mission points. These signatures were used to compute the Whitham F-functions, which were then propagated through a homogeneous atmosphere to the ground using the Whitham equal area rule. The resulting N-waves enabled the computation of aircraft shape factors, which were employed in a regression model to predict the sonic boom characteristics across the full mission profile. Finally, the integration of noise metrics and geographical information system software provided the evaluation of environmental impact and population noise exposure.

In the framework of the European project MOREandLess, under Horizon 2020 program, this work aims to contribute to the growing research on supersonic aircraft for commercial use. Through collaboration between ISL and CIRA, a series of outdoor investigation activities were conducted to produce a large amount of high-quality experimental data suitable for both characterizing the sonic boom and for validating or refining existing and novel analytical methods for sonic boom prediction. The sonic boom is the massive thunder-like noise produced when an aircraft breaks through the sound barrier, representing one of the most persistent challenges of the supersonic regime. To address this issue, considerable efforts were devoted to developing various demonstrators and evaluating their impact on the intensity of sonic booms. A first test campaign, consisting of five free-flight tests, was carried out on October 4th and 5th, 2022, at the ISL firing range in Saint-Louis, France. During these tests, a reduced and slightly modified version of the STRATOFLY MR3 vehicle was launched using a 91 mm powder cannon, reaching an initial Mach number of approximately 4.7. To capture the sonic boom, ISL and CIRA deployed various types of sensors in the field. The collected data was subsequently processed to generate a sonic boom directivity diagram for the model and a comparison with Whitham’s modified linear theory predictions.