Design Requirements of Acoustic Flight LAB Platform

Economic aircraft design demands for short development times. In frame of interior noise this requires reliable prediction methods for the design process, where the complex interaction of the excitation/fuselage as well as the radiation to the cabin is captured. Especially in the mid frequency range between 80-250Hz modern finite element based numerical models still show a lack of accuracy for a full aircraft configuration.However it is difficult to find out which part of the model has the highest impact the accuracy. Flight tests/ground tests of full aircraft configurations have an inherent high complexity and only a limited observability. Therefore in frame of the Lufo-4 funded project COCLEA an acoustic design platform is developed to serve as basis to improve numerical models by stepwise increase of the complexity. The main design requirements are: realistic excitation, fuselage structure with low complexity and clean boundary conditions.In this paper the importance of these requirements are demonstrated by results from an existing platform (A400M Fuselage Demonstrator). Here the limits due to high complexity and boundary conditions are shown by comparison of numerical model with detailed test data. Furthermore first results of the excitation reproduction system consisting out of 128 speaker array are presented.