Benchmark for modelization of acoustic transmission loss applied to helicopter trim panels

This paper describes the physical, mathematical and numerical approaches applied by laboratories of "Helicopter Garteur Action Group AG20" to vibro-acoustic behavior of helicopter trim-panels. The aim of this numerical activity is to conduct a benchmark study involving different models in order to estimate their framework for using for realistic trim panels. The calculated quantity is the acoustic transmission loss allowing to determine the efficiency of panels to reduce an incident noise. It represents the ratio between incident acoustic power, generally produced by a diffuse acoustic field, and the acoustic power radiated by the panel.