A model for flow-induced acoustics in corrugated pipes

Waves and vortex shedding in corrugated pipes during gas injection can produce distinct tonal noise and structural vibration. In this study, we propose a model which couples an acoustic pipe and self-excited oscillation with vortex shedding over the cavity. In the model, the acoustic response of the corrugated pipe is simulated by connecting the lossless medium moving with a constant velocity with a source based on discrete distribution of van der Pol oscillators arranged along the pipe. Our time accurate solutions exhibit dynamic behaviour consistent with that experimentally observed, including the lock-in frequency of vortex shedding and pipe oscillation, and the onset fluid velocity capable of generating the lock-in.