Research on Vibro-acoustic Prediction and Passive Control Technique of a Rocket-Payload Model

This paper deals with the vibro-acoustic prediction and passive control of a rocket-payload coupled model based on the statistical energy analysis (SEA). Firstly, the coupled model is built and the external loads inputting to the SEA model are determined. The external loads include the impulse force of the liquid rocket motor, the accelerations of the thrust chamber and turbo-pump, the sound pressure level of thrust chamber nozzle, which come from the ground-test, and the turbulent boundary layer of the payload fairing, which come from the calculating result by AutoSEA2 software. Secondly, the vibro-acoustic environment in the payload fairing is calculated using AutoSEA2 software. Finally, the passive control technique to reduce the vibro-acoustic level in the payload fairing are proposed, including laying acoustic blanket inside the payload fairing, increasing the main parts´ damp of the liquid rocket motor and the damp of the connect part between launch vehicle and liquid rocket motor. Results indicate that the SEA theory is viable to predicted the vibro-acoustic environment of the spacecraft, and the passive control technique for sound and vibration reduction in this paper is effective.