Deflector shape impact on aero-acoustic noise generation and propagation

Abstract

The vibroacoustic loading generated during the launch of space vehicles can cause the failure of electronic and mechanical components. Therefore, the prediction and mitigation of these vibroacoustic levels are crucial to improve the reliability of launchers and payload comfort. Because a properly designed flame deflector has the power to significantly reduce the acoustic pressure level, the aeroacoustics characteristics of diverse types of flame deflectors must be understood. Three different deflector geometries have been analysed: a wedge-type deflector, which is currently used on the VEGA rocket launch pad, a 30-degree inclined deflector, since new studies highlight its noise reduction capacity, and a flat deflector, since the impact on a flat plate is the simplest case of reflection. The sound generation and propagation in the launch platform full domain for each case were studied using dedicated computational fluid dynamics in BSC MareNostrum. To assess noise generation, the main shock waves were identified, and the evolution of the generated sound pressure was assessed. Moreover, the sound pressure levels at the fairing surface have been studied. Further research is focused right now on the use of an efficient solver running on graphics processing units that is capable of computing large-scale turbulence.

Aeroacoustic Improvements during Lift-off of Launch Vehicles

“…Therefore, because a properly designed flame deflector can significantly reduce the acoustic pressure level, we study the aeroacoustic characteristics of diverse flame deflectors for the VEGA launch vehicle. The results presented in this section have been published in the article [186]. This work was devised before the LES model was developed, so the URANS model of OpenFOAM was used.…”