6533b7d2fe1ef96bd125dda1

RESEARCH PRODUCT

Study and Simulation of Helicopter Gearboxes Noise

subject

description

International audience; Main gearbox is one of the main noise sources in helicopter cabin. In order to improve the comfort of customers and reduce the health impact, acoustic and vibration mechanisms of gearboxes have to be understood and simulated during development phases. Thus, we first present the global methodology chosen to compute main gearboxes noise in helicopter cabins. Secondly, we described the way we compute mechanical excitation sources induced from gear mesh, static transmission error and meshing stiffness. Depending on the type of gear, we compute those using either analytical specially developed code or EC codes. Thirdly, we propose a modeling to compute dynamic loads on bearings being the excitation sources for the housing. We propose to compute them in the case of transmissions composed of several cylindrical and/or spiral bevel gear pairs. This modeling relies on a finite element method generally used in the case of overall acoustic and vibration studies of rotating machines. At last, a realistic example is proposed and some conclusions are drawn concerning the capability of this model.