Simulation and evaluation of noise and vibration reduction techniques in a helicopter cabin using SEA

Increasing acoustic comfort inside the helicopter is demanded especially by VIP customer. Noise reduction is a big challenge, due to the high acoustic levels generated by the main sources (gearbox, engines, rotors, hydraulic and oil pumps) and requires the synergy of all available technologies. A mock-up built using a real helicopter is used like test-bench in order to apply and to validate noise and vibration reduction systems. In parallel, a SEA analytical model has been developed to reproduce the test results both in term of noise transfer path and of acoustic levels in running condition. The validated digital mock-up in "bare" configuration will be then used to compare several trimmed configurations to select only the most promising to be tested, saving time and costs required by experimental tests.