Finite element modeling of noise emission in mechanoacoustic systems with rotating subdomains

Vibroactive mechanisms often contain rotating elements that determine their acoustic characteristics. Existing numerical methods make it possible to calculate the acoustics of such rotating systems exclusively in the time domain, while these methods require large computing power and accumulate a calculation error with each subsequent time step. In this paper, a numerical method that allows modeling of the noise emission of rotating mechanoacoustic systems in the frequency domain has been developed. The method is based on the separation of rotating and stationary subdomains from the computational domain and combining them into a single finite element model using a special contact interface that considers the circumferential sliding of the finite element mesh. The method enables one to predict sound emission both at the main frequency of the source and at frequencies that are multiples of the rotation frequency of the elastic body. The method is verified on simple analytical models.