Acoustic analysis of H-IIA launch vehicle fairing using SEA

Acoustic tests with the required specific spectrum for launch vehicle payload are performed in Environmental and Structural Test Lab., TKSC, NASDA. This article demonstrates a method to combine experimental and analytical parameters for Statistical Energy Analysis (SEA) to predict the actual interior acoustic pressure level at high frequency of the H-IIA launch vehicle fairing precisely, considering the payload effects. Damping loss factors and coupling loss factors of fairing and interior cavity are significant parameters for the accuracy of SEA model. This article discusses the approach to extract the equivalent damping loss factors and coupling loss factors measured in-situ by impact and acoustic excitation experiments to raise the analytical accuracy of SEA model. The combined hybrid model of H-IIA fairing is validated in ground acoustical environment test inside the reverberation room conducted at Tsukuba Space Center. Results indicate that good agreements between analysis and measurement are achieved.