Implementation of acoustic materials to the VLS-1 Fairing - a sensitivity analysis using SEA

satellite launchers are submitted to severe acoustic loads mainly during lift-off where spl achieve, at the upper parts, values within the range of 140-160 db. such an excitation can damage embedded elements, if energy attenuation measures are not adopted. in view of managing the plf vibro-acoustic environment, numerical techniques are applied to predict elasto-acoustic behavior. this manuscript presents a numerical study on the design of acoustic insulation for the vls-1 fairing compartment. an excitation profile based on the literature is applied on a sea coupled model of this structural-acoustic system and absorbing materials are added to the model. two parameters of the absorbing material layer are analyzed: thickness and covered area. two nct modeling approaches are used to simulate the effect of blanketing the vls-1 fairing: acoustic materials biot's parameters, given by the manufacturer, and material samples absorption coefficient, measured in a kundt tube. results show that an increase in the blanket thickness from 7.62 to 12.7 cm results in a tl of 1.7 db ospl, while variations of up to 3.0 db ospl are calculated if the fairing cavity blanketed area varies from 30% to 100%.