Analysing the effects of integration on the Noise from Electric Aircraft Motors

Abstract

A main source of noise and vibration generated by an electrified aircraft is the propulsion system. Recent studies indicate that the electric motor will cause additional noise and thus contribute to the already existing noise sources. The goal of the current project is to determine how the noise generated by the electric drive train changes with the integration of different parts into the propulsion system. In order to analyze the noise and vibration produced by a Permanent Magnet Synchronous Motor (PMSM), an applicable aircraft motor topology was chosen in a first step and an FEM simulation was used to determine the natural frequencies and modal shapes. In a second step, the influence of the motor integration, consisting of a casing, cooling system, and shaft, on the eigenmodes and eigenfrequencies was investigated. Finally, the electric machine system was implemented into a nacelle and the resulting structural dynamic behavior of the whole system was determined. Comparing and evaluating the structural dynamic behavior determined in each step helps to better understand the physical noise radiation process. This is necessary in order to develop noise reduction technologies for future electrified aircraft engines.