Investigation on continuous pressure wave in a periodic transient flow using a three-dimensional CFD model

This paper explores continuous pressure wave characteristics and flow features in a periodic transient flow induced by a rotary pressure wave generator. A three-dimensional CFD model based on the realizable k-ϵ turbulence model is established to conduct the simulations. The results show that the turbulent kinetic energy evolution in the periodic transient flow is similar to that in an instantaneous transient flow. In addition, there exists an optimal frequency corresponding to the maximum wave amplitude, which is closely related to the fluid properties and system parameters. When the disturbance frequency is less than the optimal frequency, the pressure and velocity derivative satisfy a linear relation in all zones of the upstream pipe. In contrast, a linear zone away from the rotor is locally formed at regions where the linear relation is approximately valid. Correspondingly, a nonlinear zone is near the rotor where the linear relation is inapplicable. The disturbance frequency significantly affects the axial wave amplitude distribution.