Towards numerical noise prediction for future electrified aircraft engines

The interior permanent magnet synchronous machine (IPMSM) has high potential to be widely applied in electrical flight propulsions, with the goal of making civil aviation more climate-friendly and quieter. As a key component of the electrical flight propulsion system, the noise generated by IPMSM must be investigated and modeled to understand its physical noise generation mechanisms and its contribution to the overall aircraft noise.

A key factor of the vibration and acoustic noise in electrical motors is the radial electromagnetic stress acting in the motor air-gap. In this paper, a multi-physic domain based model for estimating the vibroacoustic behavior of an IPMSM due to the radial electromagnetic stress is presented. Due to the lack of physical models for IPMSM with the power density required in aviation, an existing electric motor design from automotive industry is used as a benchmark. The basic data of the IPMSM with 8 poles and 48 slots is provided in Table 1 and a cross section is shown in Fig. 1.

Based on the selected model, the first step of the calculation process (see Fig. 2) is the electromagnetic simulation that provides the radial electromagnetic stress. Subsequently, modal analysis and structural harmonic response analyses are performed to simulate the vibration behavior of the system. Finally, the model is utilized to predict the far-field sound pressure level by coupling multi-physics domain simulation packages together.