Improved acoustical properties of launcher fairings

Research Project, 2012 – 2015

Extremely high sound pressures are created by the rocket engines during lift-off when launching rockets carrying satellites and other payload. The high sound pressure causes high vibrations on the satellite that is inside the payload fairing at the nose end of the rocket. The fairing function is to provide a safe acoustic environment during lift-off and throughout the flight. A specified requirement for noise reduction has to be achieved through fairing acoustical design. Together with the propulsion noise, the acoustical properties of the fairing determine the spacecraft acoustic environment. These properties are therefore key properties for the potential customers of the rocket.

The fairings of today are made of a lightweight, stiff and slightly damped sandwich constructions that require careful consideration for acoustic transmission performance. The acoustical protection is achieved with the addition of a large amount of soundproofing and sound absorbing materials that give disadvantages such as increased weight and reduced payload volume.

The goal of the proposed project is to develop new fairings on a conceptual level which can provide overall improved performance in terms of payload comfort and cost. This means that the acoustical properties must be integrated in the design of the fairing from the start. Theoretical models, computer simulations and experimental testing support the development of the new fairing concept.

The project is carried out at the Divison of Applied Acoustics in the research group Vibroacoustics.